tag:theconversation.com,2011:/uk/topics/phosphorus-1878/articlesPhosphorus – The Conversation2024-02-13T13:20:14Ztag:theconversation.com,2011:article/2151272024-02-13T13:20:14Z2024-02-13T13:20:14ZFlowers grown floating on polluted waterways can help clean up nutrient runoff and turn a profit<figure><img src="https://images.theconversation.com/files/573604/original/file-20240205-30-14awa7.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6173%2C4087&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The cut flowers could pay for themselves and even turn a profit.</span> <span class="attribution"><span class="source">Margi Rentis</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Flowers grown on inexpensive floating platforms can help clean polluted waterways, over 12 weeks extracting 52% more phosphorus and 36% more nitrogen than the natural nitrogen cycle removes from untreated water, according to our <a href="https://doi.org/10.1016/j.envadv.2023.100405">new research</a>. In addition to filtering water, the cut flowers can generate income via the <a href="https://www.ers.usda.gov/data-products/chart-gallery/gallery/chart-detail/?chartId=106472">multibillion-dollar floral market</a>. </p>
<p>In our trials of various flowers, giant marigolds stood out as the most successful, producing long, marketable stems and large blooms. Their yield matched typical <a href="https://www.lsuagcenter.com/articles/page1662131594449">flower farm production</a>.</p>
<h2>Why it matters</h2>
<p><a href="https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution">Water pollution</a> is caused in large part by runoff from farms, urban lawns and even septic tanks. When it rains, excess phosphorus, nitrogen and other chemicals wash into lakes and rivers.</p>
<p>These nutrients feed algae, leading to widespread and harmful algae blooms, which can severely lower oxygen in water, creating “<a href="https://unstats.un.org/sdgs/report/2021/goal-14/">dead zones</a>” where aquatic life cannot survive. Nutrient runoff is a critical issue as urban areas expand, affecting the health of water ecosystems. </p>
<p>Water pollution is an escalating crisis in our area of Miami-Dade and Broward counties in Florida. The <a href="https://storymaps.arcgis.com/stories/b5d43852c8984a4c8db4d077ec04bd35">2020 Biscayne Bay fish kill</a>, the largest mass death of aquatic life on record for the region, serves as a stark reminder of this growing environmental issue.</p>
<h2>How we do our work</h2>
<p>We study <a href="https://case.fiu.edu/earth-environment/agroecology/">sustainable agriculture</a> and <a href="https://crestcache.fiu.edu/">water pollution</a> in South Florida.</p>
<p>Inspired by traditional floating farm practices, including the Aztecs’ <a href="https://www.bbc.com/travel/article/20221009-the-return-of-aztec-floating-farms">chinampas in Mexico</a> and the <a href="https://www.pbs.org/video/the-secret-islands-of-the-everglades-lncj6r/">Miccosukees’ tree island settlements in Florida</a>, we tested the idea of growing cut flowers on floating rafts as a way to remove excess nutrients from waterways. Our hope was not only that the flowers would pay for themselves, but that they could provide jobs here in Miami, the center of the U.S. cut-flower trade.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An outdoor tank contains a large floating perforated mat. Each hole contains a young plant." src="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573507/original/file-20240205-23-zkmaeu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Chemical conditions in the test tanks were the same as in nearby polluted waterways.</span>
<span class="attribution"><span class="source">Jazmin Locke-Rodriguez</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>We floated 4-by-6-foot (1.2-by-1.8-meter) mats of inexpensive polyethylene foam called <a href="http://www.beemats.com/">Beemats</a> in 620-gallon (2,300-liter) outdoor test tanks that mirrored water conditions of nearby polluted waterways. Into the mats we transplanted flower seedlings, including zinnias, sunflowers and giant marigolds. The polluted tank water was rich in nutrients, eliminating the need for any fertilizer. As the seedlings matured into plants over 12 weeks, we tracked the tanks’ improving water quality. </p>
<p>Encouraged by the success of the marigolds in our tanks, we moved our trials to the nearby canals of Coral Gables and Little River. We anchored the floating platforms with 50-pound (22.7-kilograms) weights and also tied them to shore for extra stability. No alterations to the landscape were needed, making the process simple and doable.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Closeup photo of base of a marigold plant showing a tangle of visible roots." src="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573517/original/file-20240205-15-ot28qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some plants grow roots in places – such as the stem – other than where their original roots began.</span>
<span class="attribution"><span class="source">Jazmin Locke-Rodriguez</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>What still isn’t known</h2>
<p>The success of the giant marigolds might be linked to the extra roots that grow from their stems known as <a href="https://propg.ifas.ufl.edu/05-cuttings/01-terminology/01-cuttingterms-adventitiousroot.html">adventitious roots</a>. These roots likely help keep the plants stable on the floating platforms. Identifying additional plants with roots like these could help broaden plant choices. </p>
<p>Future raft designs may also need modifications to ensure better stability and growth for other cut-flower and crop species. </p>
<h2>What’s next</h2>
<p>Our promising findings show floating cut-flower farms could be a sustainable option for mitigating water pollution. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Nim52wi_4z4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How floating cut-flower farms can clean polluted waterways.</span></figcaption>
</figure>
<p>One of us (Locke-Rodriguez) is expanding this research and working to scale up floating farms in South Florida as a demonstration of what could take place in the many locations facing similar issues worldwide.</p>
<p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take on interesting academic work.</em></p><img src="https://counter.theconversation.com/content/215127/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jazmin Locke received funding from the USDA-NIFA-NNF and NSF-CREST as a PhD student to help fund this dissertation research at Florida International University.</span></em></p><p class="fine-print"><em><span><a href="mailto:jayachan@fiu.edu">jayachan@fiu.edu</a> receives funding from USDA-NIFA. </span></em></p>Phosphorus and nitrogen contribute to water pollution and cause harmful algal blooms. New research shows how mats of floating flower beds can take advantage of these nutrients while cleaning the water.Jazmin Locke-Rodriguez, Post Doctoral Associate in the Institute of Environment, Florida International UniversityKrishnaswamy Jayachandran, Professor of Agroecology, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2077142023-06-14T23:03:46Z2023-06-14T23:03:46ZFor the first time, astronomers have found life-supporting molecules called phosphates on Enceladus<figure><img src="https://images.theconversation.com/files/531898/original/file-20230614-22-z3g0a3.png?ixlib=rb-1.1.0&rect=742%2C233%2C3155%2C1760&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">NASA/JPL/Space Science Institute</span></span></figcaption></figure><p>The search for habitable conditions beyond Earth has just become more interesting with the discovery of biologically available phosphorus from one of Saturn’s moons. Phosphorus is the most elusive of the six crucial elements needed for life.</p>
<p>In research <a href="https://doi.org/10.1038/s41586-023-05987-9">published today in Nature</a>, data from the Cassini spacecraft were used to find phosphorus compounds called phosphates in <a href="https://solarsystem.nasa.gov/news/13021/put-a-ring-on-it/">Saturn’s E ring</a> – one of the fainter outer rings of the planet.</p>
<p>These compounds likely came from the ice volcano (cryovolcano) plumes from the <a href="https://theconversation.com/waterworld-cassini-spots-the-motion-of-enceladuss-ocean-25069">sub-surface liquid water ocean</a> on Saturn’s moon Enceladus.</p>
<h2>A famous moon</h2>
<p>Enceladus seemed like a typical moon of Saturn until the Cassini spacecraft came to take a closer look. <a href="https://theconversation.com/a-look-back-at-cassinis-incredible-mission-to-saturn-before-its-final-plunge-into-the-planet-83226">Arriving at Saturn in 2005</a>, Cassini has been making <a href="https://solarsystem.nasa.gov/news/12892/cassini-10-years-at-saturn-top-10-discoveries/">discovery after discovery</a> that have catapulted Enceladus to one of the top places to look for life beyond Earth.</p>
<p>In particular, we learned Enceladus has a liquid water ocean beneath its icy surface, heated by gravitational tidal forcing – the kind of forcing that produces ocean tides on Earth.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=640&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=640&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=640&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=805&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=805&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531895/original/file-20230614-19-jl252o.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=805&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The process of organic compounds making their way onto ice grains emitted in plumes from Saturn’s moon Enceladus, where they were detected by NASA’s Cassini spacecraft.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech</span></span>
</figcaption>
</figure>
<p>This environment is tantalisingly similar to the <a href="https://theconversation.com/origins-of-life-new-evidence-first-cells-could-have-formed-at-the-bottom-of-the-ocean-126228">hydrothermal vents thought by some</a> to be the place where life may have originated on Earth. Such vents certainly host life on Earth today.</p>
<p>Most life on Earth ultimately relies on photosynthesis – generating energy from sunlight. Meanwhile, the ultimate energy source for any life on Enceladus would be the gravity of Saturn producing tides far stronger than the Moon produces on Earth, allowing a liquid water ocean despite the very cold -200°C ice crust surface.</p>
<h2>Easy sampling</h2>
<p>The Enceladus plumes have been called a “gimme” for efforts to sample the oceans of alien worlds. One wouldn’t need to land to collect a sample, nor to then launch to return it for analysis.</p>
<p>An obvious approach to sampling an ice volcano is to simply fly through it. However, this is difficult because the speed at which a space probe would encounter the plume would likely kill most organics.</p>
<p>Instead, the easiest approach is to examine the accumulation of ejected material from Enceladus in Saturn’s E ring, which is what the team did in this latest study. </p>
<p>Using this approach, researchers have previously discovered <a href="https://academic.oup.com/mnras/article/489/4/5231/5573821">complex organic molecules</a> <a href="https://www.nature.com/articles/s41586-018-0246-4">coming from Enceladus</a>. These findings confirmed that the watery environment on Enceladus supports complex chemistry involving nitrogen and oxygen.</p>
<p>However, until now we didn’t know about the availability of phosphorus on Enceladus; in many environments this element is locked in rocks.</p>
<h2>A crucial element</h2>
<p>The discovery of phosphates in Saturn’s E ring suggests phosphates could be available within the oceans of Enceladus at a concentration 100 times higher than in Earth’s oceans.</p>
<p>Phosphorus is crucial for life as we know it, partly because it is a key building block of DNA and RNA, molecules essential to all life on Earth. Phosphate is also vital for a number of other metabolic processes in all life. </p>
<p>Many of the essential components necessary for the emergence of life as we know it have thus been discovered on Enceladus. This puts it at or near the top of lists of places to search for life beyond Earth in our Solar System. </p>
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Read more:
<a href="https://theconversation.com/humans-are-still-hunting-for-aliens-heres-how-astronomers-are-looking-for-life-beyond-earth-197621">Humans are still hunting for aliens. Here's how astronomers are looking for life beyond Earth</a>
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<p>Nevertheless, this discovery is only the start of the story. For phosphate to form bonds with carbon – this type of bond is found in the backbone of DNA – we need specialised chemistry that’s very dependent on the environment.</p>
<p>We’ll need further study of the chemistry in and under the crust of Enceladus. But a future detection of organic phosphate compounds would be particularly interesting for the potential for life in the moon’s oceans.</p>
<h2>No ‘smoking gun’</h2>
<p>This research is reminiscent of the reported detection of <a href="https://theconversation.com/the-detection-of-phosphine-in-venus-clouds-is-a-big-deal-heres-how-we-can-find-out-if-its-a-sign-of-life-146185">phosphine on Venus</a> in September 2020, which was <a href="https://www.universetoday.com/158983/sofia-fails-to-find-phosphine-in-the-atmosphere-of-venus-but-the-debate-continues/">cast into doubt by later evidence</a>.</p>
<p>However, the detection method is quite different. On Venus the presence of phosphine was proposed by observing the atmosphere from Earth. The phosphates in this study were detected using an instrument orbiting Saturn called a mass spectrometer, which measured the mass of individual compounds found in the ice of the E ring.</p>
<p>To verify the analysis, the authors created a water solution on Earth very similar to the predicted Enceladus ocean.</p>
<p>That said, both detection methods carry a risk of misidentification, where a different molecule that’s not phosphine is actually responsible for the result. </p>
<p>It would be great to have a “smoking gun” for life beyond Earth, but realistically it will instead be a trickle of evidence that grows as we discover more about these environments. </p>
<p>The study published today is one more piece of evidence supporting the fact that Enceladus may be a great location in our search for extraterrestrial life. </p>
<hr>
<p><em>Acknowledgements: We thank Prof Steve Benner from The Foundation For Applied Molecular Evolution for his insight and contributions to this article.</em></p><img src="https://counter.theconversation.com/content/207714/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Phosphorus is the most elusive element crucial for life as we know it – and we now have the first evidence there’s some available in the oceans of Enceladus.Laura McKemmish, Lecturer, UNSW SydneyAlbert Fahrenbach, Senior Lecturer, UNSW SydneyMartin Van Kranendonk, Professor and Director of the Australian Centre for Astrobiology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1989032023-02-08T08:48:18Z2023-02-08T08:48:18ZPulses are packed with goodness: Five cool things you should know about them<figure><img src="https://images.theconversation.com/files/508577/original/file-20230207-19-vtdp97.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">pbd Studio/shutterstock</span></span></figcaption></figure><p>Each year on February 10, the United Nations commemorates what probably sounds to many like a strange occasion: <a href="https://www.un.org/en/observances/world-pulses-day">World Pulses Day</a>. </p>
<p>But, as a researcher focused on <a href="https://www.slcu.cam.ac.uk/people/nadia-radzman">forgotten and underutilised legumes</a>, I think the initiative is an important step towards food security. Getting people to eat more pulses can ultimately help achieve <a href="https://www.un.org/sustainabledevelopment/hunger/">UN Sustainable Development Goal 2: Zero Hunger</a>.</p>
<p>First, for clarification, “legumes” and “pulses” have different meanings. “Legumes” are all plants belong to the family <em>Leguminosae</em> or <em>Fabaceae</em>, while “pulses” are the dried seeds of legume plants. Pulses include beans, lentils and chickpeas.</p>
<p>One reason that legume plants offer such promise in ending hunger is that they don’t need good soil or nitrogen fertilisers. Plants need nitrogen to build important molecules such as protein and DNA. Most legumes can thrive in poor soil by fixing nitrogen gas from the air for their own use. This happens through symbiotic interaction with friendly bacteria known as rhizobia. The rhizobia are housed inside structures called nodules on the plant’s roots.</p>
<p>Thanks to their nitrogen-fixing ability, pulses are nutritional powerhouses: high in protein and fibre, and low in fat. </p>
<p>But that’s not the only interesting thing about legumes and pulses. In honour of World Pulses Day 2023, I would like to highlight five pulses that have unique properties and stories.</p>
<h2>1. The African yam bean: high protein beans and underground tubers</h2>
<p>The African yam bean (<em>Sphenostylis stenocarpa</em>) offers two servings of food: beans and underground tubers. The tubers have higher protein content than any non-legume tuber crops like potato and cassava, and the beans are also high in protein. Their nutritional value was proved <a href="https://link.springer.com/chapter/10.1007/978-1-4613-0433-3_18">during the Nigerian Civil War (1967-1970)</a> when the beans were cooked with amaranthus, telfaria or cassava leaves to feed the malnourished in war-affected areas.</p>
<p>This crop is native to Africa and was <a href="https://link.springer.com/article/10.1007/BF02866625">once grown across the African continent</a>. Researchers have proposed that it may have been <a href="https://link.springer.com/article/10.1007/BF02866626">domesticated multiple times in west and central Africa</a>. Today, it is <a href="https://www.sciencedirect.com/science/article/pii/S240584402032301X">mostly grown as security or subsistence crop</a>, rather than commercially. But its high protein content and drought tolerance are attracting increasing interest.</p>
<h2>2. Common bean: diversity and environmental versatility</h2>
<p>The common bean (<em>Phaseolus vulgaris</em>) comes in many varieties around the world. Examples are black beans, red kidney beans and pinto beans – they look different but they are the same species. What’s special about them is that they can <a href="https://link.springer.com/article/10.1023/A:1024199013926">pair with a larger number of rhizobial species</a> than <a href="https://www.frontiersin.org/articles/10.3389/fmicb.2015.00945/full">other legumes</a> can. This may have helped the common bean to thrive outside its native land and diversify in various habitats around the world. It’s able to fix nitrogen in different environments, making it a resilient legume species.</p>
<h2>3. Pea: a role in early understanding of genetics</h2>
<p>The pea (<em>Pisum sativum</em>) is among the oldest domesticated crops in the world. It contributed to the understanding of genetics, thanks to <a href="https://www.britannica.com/biography/Gregor-Mendel">Gregor Mendel’s</a> famous <a href="https://www.nature.com/scitable/topicpage/gregor-mendel-and-the-principles-of-inheritance-593/">experiment</a> with pea plants. Mendel observed the way that different physical properties of the pea plants were inherited: pod shape, seed shape, seed colour, unripe pod colour, flower colour, stem length, and flower placement. He crossed two pea plants that had different properties and observed the seven traits in the subsequent generations for two years. From this experiment, he established <a href="http://www.dnaftb.org/1/bio.html">Mendel’s Rules of Inheritance</a> – still applicable in modern day genetic study. </p>
<p>The rich genetic diversity of the pea is also <a href="https://www.mdpi.com/2073-4395/2/2/74">a valuable resource for important crop traits</a> that can withstand various weather conditions due to climate change.</p>
<h2>4. Chickpea: built for drought</h2>
<p>Many pulses are drought tolerant and use less water for production than animal-sourced proteins, especially beef. Chickpea (<em>Cicer arietinum</em>) is known to be <a href="https://www.frontiersin.org/articles/10.3389/fpls.2019.01759/full">highly drought tolerant</a>. Most of this crop is grown under rainfed conditions in arid and semi-arid areas. This special ability to grow where water is scarce is <a href="https://link.springer.com/article/10.1007/s10722-006-9197-y">more prominent in wild species of chickpea</a>. Wild chickpeas can also tolerate temperatures up to 40°C – another valuable genetic resource for better drought tolerance in modern chickpeas. </p>
<p>Still, chickpea yield is highly compromised when there is lack of water. Therefore, <a href="https://www.nature.com/articles/s41588-019-0401-3">scientists are looking for beneficial traits</a> that can reduce the yield loss in chickpeas during drought. This may contribute to a more secure food source in the midst of climate change.</p>
<h2>5. Lupins: special cluster roots to seek nutrients</h2>
<p>White lupins (<em>Lupinus albus</em>), yellow lupins (<em>Lupinus luteus</em>) and pearl lupins (<em>Lupinus mutabilis</em>) can <a href="https://link.springer.com/article/10.1023/B:PLSO.0000016544.18563.86">form special roots</a> to get more nutrients without the need for additional fertilisers. Plants need not only nitrogen but phosphorus. Usually it’s given to plants in fertiliser to increase crop yield. <a href="https://extension.umn.edu/phosphorus-and-potassium/understanding-phosphorus-fertilizers#process-619211">Phosphate fertiliser is made from phosphate rock</a> –- a non-renewable resource which is rapidly depleting through agricultural use. The white, yellow, and pearl lupins have unique root modifications called cluster roots that can liberate phosphorus from soil particles when the nutrient is low. These roots <a href="https://link.springer.com/article/10.1007/s11104-004-2725-7">look like bottlebrush</a> and are formed only when the level of phosphorus in the soil is low. These cluster roots <a href="https://academic.oup.com/aob/article/110/2/329/2769292">exude negatively charged compound called carboxylate</a> that can liberate phosphorus from the soil and make it available for the plant to use. So lupins do not have to rely on phosphate fertilisers and can even help neighbouring plants by increasing the phosphorus level in the soil.</p>
<h2>Food security</h2>
<p>Pulses deserve our attention not just on February 10 but every day. The five pulses I’ve presented here can serve as sustainable protein sources and make food systems more diverse. They can greatly contribute to better food security in the future.</p><img src="https://counter.theconversation.com/content/198903/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nadia Radzman is a research associate at the Sainsbury Laboratory Cambridge University that receives funding from the Gatsby Foundation. She is the co-chair of Cambridge University Food Security Society and a steering committee member of the Cambridge Global Food Security interdisciplinary research centre.</span></em></p>Pulses are important for many reasons. They are packed with nutrition, resilient and crucial for achieving food security in Africa.Nadia Radzman, Research Associate in Plant Biology, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1965382022-12-16T15:48:40Z2022-12-16T15:48:40ZPhosphorus supply is increasingly disrupted – we are sleepwalking into a global food crisis<figure><img src="https://images.theconversation.com/files/501356/original/file-20221215-18-61v94h.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5751%2C3819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">oticki / shutterstock</span></span></figcaption></figure><p>Without phosphorus food cannot be produced, since all plants and animals need it to grow. Put simply: if there is no phosphorus, there is no life. As such, phosphorus-based fertilisers – it is the “P” in “NPK” fertiliser – have become critical to the global food system. </p>
<p>Most phosphorus comes from non-renewable phosphate rock and it cannot be synthesised artificially. All farmers therefore need access to it, but 85% of the world’s remaining high-grade phosphate rock is concentrated in just five countries (some of which are “geopolitically complex”): Morocco, China, Egypt, Algeria and South Africa. </p>
<p>Seventy per cent is found in <a href="https://investingnews.com/daily/resource-investing/agriculture-investing/phosphate-investing/top-phosphate-countries-by-production/">Morocco alone</a>. This makes the global food system extremely vulnerable to disruptions in the phosphorus supply that can lead to sudden price spikes. For example, in 2008 the price of phosphate fertilisers rocketed 800%.</p>
<p>At the same time, phosphorus use in food production is extremely inefficient, from mine to farm to fork. It runs off agricultural land into rivers and lakes, polluting water which in turn can kill fish and plants, and make water too toxic to drink. </p>
<p>In the UK alone, less than half of the 174,000 tonnes of imported phosphate are <a href="https://www.sciencedirect.com/science/article/pii/S0301479722005941?via%3Dihub">actually used productively to grow food</a>, with similar phosphorus efficiencies measured <a href="https://link.springer.com/article/10.1007/s13280-019-01255-1">throughout the EU</a>. Consequently, the planetary boundaries (the Earth’s “safe space”) for the amount of phosphorus flow into water systems <a href="https://iopscience.iop.org/article/10.1088/1748-9326/6/1/014009">have long been transgressed</a>.</p>
<p>Unless we fundamentally transform the way we use phosphorus, any supply disruption will cause a global food crisis since most countries are largely dependent on imported fertilisers. Using phosphorus in a smarter way, including using more recycled phosphorus, would also help already stressed rivers and lakes. </p>
<p>We are currently experiencing the third major phosphate fertiliser price spike in 50 years, thanks to the COVID-19 pandemic, China (the biggest exporter) imposing <a href="https://www.reuters.com/article/china-fertilizers-quotas-idUSKBN2OQ0KY">export tariffs</a>, and Russia (one of top five producers) banning exports and then invading Ukraine. Since the start of the pandemic, fertiliser prices have risen steeply and at one point had quadrupled within two years. They are still at their <a href="https://openknowledge.worldbank.org/bitstream/handle/10986/37223/CMO-April-2022-special-focus.pdf">highest levels since 2008</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graph of global phosphate prices since 1970" src="https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=314&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=314&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=314&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=395&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=395&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501533/original/file-20221216-22499-bhmjst.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=395&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Prices spiked in 2008 and again over the past year. DAP and TSP are two of the main fertilisers extracted from phosphate rock.</span>
<span class="attribution"><span class="source">Dana Cordell; data: World Bank</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Stop ignoring phosphorus</h2>
<p>Despite its critical importance, there is no comprehensive global framework for phosphorus governance. It is largely ignored in international policy discussions, and in countries where phosphorus regulation does exist, it is often dated and fails to address food security. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of phosphorus use" src="https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=785&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=785&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=785&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=986&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=986&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501542/original/file-20221216-11363-qlu8jq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=986&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How phosphorus goes from mine to food.</span>
<span class="attribution"><span class="source">UK Phosphorus Transformation Strategy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Policies have generally focused on removing phosphorus from wastewater to prevent water pollution or encouraging farmers to fertilise fields with phosphorus-rich animal manure or to use less phosphorus in the first place. These are fine, but they are piecemeal and ignore important inefficiencies at other stages in the food supply chain, for example in producing fertiliser, or in food processing or arising from our <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab9271/meta">dietary choices</a>.</p>
<p><a href="https://theconversation.com/time-for-policy-action-on-global-phosphorus-security-5594">For more than a decade</a>, scientists have been warning that if no one takes responsibility for ensuring phosphorus security, further disruptions in its supply can have major consequences for the food system. Vulnerable farmers could be pushed to the brink and global crop yields severely reduced. We are essentially sleepwalking into a food crisis.</p>
<h2>The first comprehensive national strategy</h2>
<p>But there is still time to wake up. We have put together the first ever <a href="https://doi.org/10.5281/zenodo.7404622">UK National Phosphorus Transformation Strategy</a> to help guide the country away from its current unsustainable situation. If the UK government and institutions were to adopt this strategy, we hope it could trigger a broader transformation elsewhere.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="boxes with words and images" src="https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=271&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=271&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=271&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=341&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=341&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501531/original/file-20221216-32459-xer2tt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=341&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">What the strategy hopes to achieve.</span>
<span class="attribution"><span class="source">UK Phosphorus Transformation Strategy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Surprisingly, despite being almost entirely dependent on imported phosphorus in fertilisers and animal feed, our team’s <a href="https://www.sciencedirect.com/science/article/pii/S0301479722005941?via%3Dihub">research</a> shows the UK theoretically has enough phosphorus already circulating in the food system: 90,000 tonnes per year of “legacy phosphorus” accumulate in agricultural soils, 26,000 tonnes per year leak into water bodies and 22,000 tonnes are sent to landfill and construction. These hotspots of phosphorus inefficiency and loss represent a critical resource, which could instead be used productively. </p>
<p>The strategy identifies six phosphorus priority pathways that can turn that around, ranging from the development of innovative technologies to financial incentives for industry and engaging communities in the changes needed. </p>
<p>This includes things like supporting the roll-out of “biodigesters” to process bulky animal manures and food wastes into concentrated and nutrient-rich fertilisers that can be more cost-effectively transported across the country to crop production areas. Or harmonising national policies to incentivise both phosphorus removal to prevent pollution, and stimulate the productive reuse of phosphorus-rich wastes for farmers. </p>
<p>The good news is that some of these actions are already underway at a small scale. If they are scaled up and others are introduced and become part of mainstream operations, then the UK’s phosphorus system can become more resilient. For that to happen, we need the commitment of all sectors involved and we need to address the issues in an integrated and collaborative way. </p>
<p>Importantly, the strategy has been developed after extensive consultation with farmers, regulators, policy-makers, food producers, wastewater companies and environmental managers. This should give us the confidence that change is possible.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RDhC1zeB350?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Phosphorus and the UK food system: a video made by Seed in collaboration with the authors.</span></figcaption>
</figure>
<hr>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
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<p class="fine-print"><em><span>The Phosphorus Transformation Strategy was produced as part of the RePhoKUs project (The role of phosphorus in the sustainability and resilience of the UK food system) funded by BBSRC, ESRC, NERC, and the Scottish Government under the UK Global Food Security research programme (Grant No. BB/R005842/1). RePhoKUs project was led by Lancaster University with the University of Leeds, the University of Technology Sydney AFBI, UK CEH.</span></em></p><p class="fine-print"><em><span>Brent Jacobs receives funding from the UK Research Councils (BBSRC, ESRC, NERC), the Scottish Government, the European Union, and the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Dana Cordell receives funding from the UK Research Councils (BBSRC, ESRC, NERC), the Scottish Government, the European Union, and the Australian Research Council. </span></em></p>This crucial fertiliser component is mostly found in just five countries.Julia Martin-Ortega, Professor, Sustainability Research Insitute. Associate Director water@leeds, University of LeedsBrent Jacobs, Research Director, Institute for Sustainable Futures, University of Technology SydneyDana Cordell, Associate Professor, Institute for Sustainable Futures, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1862862022-07-18T12:26:45Z2022-07-18T12:26:45ZTo reduce harmful algal blooms and dead zones, the US needs a national strategy for regulating farm pollution<figure><img src="https://images.theconversation.com/files/474164/original/file-20220714-32338-xz3rmp.jpeg?ixlib=rb-1.1.0&rect=52%2C0%2C8713%2C5835&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Satellite photo of an algal bloom in western Lake Erie, July 28, 2015.</span> <span class="attribution"><a class="source" href="https://eoimages.gsfc.nasa.gov/images/imagerecords/86000/86327/erie_oli_2015209_lrg.jpg">NASA Earth Observatory</a></span></figcaption></figure><p>Midsummer is the time for forecasts of the size of this year’s “dead zones” and algal blooms in major lakes and bays. Will the <a href="https://www.nola.com/news/environment/article_bfc1ba32-e2ac-11ec-9909-5fd0e4edb56b.html">Gulf of Mexico dead zone</a> be the size of New Jersey, or only as big as Connecticut? Will Lake Erie’s bloom blossom to a <a href="https://www.toledoblade.com/local/2014/08/03/Water-crisis-grips-area/stories/20140803090">human health crisis</a>, or just devastate the <a href="https://www.ectinc.com/projects/economic-benefits-costs-of-reducing-harmful-algal-blooms-in-lake-erie/">coastal economy</a>? </p>
<p>We are scientists who each have spent almost 50 years figuring out <a href="https://scholar.google.com/citations?user=ARkaE6cAAAAJ&hl=en">what causes dead zones</a> and what it will take to resuscitate them and reduce <a href="https://scholar.google.com/citations?user=-K4wV5QAAAAJ&hl=en">risks of toxic blooms of algae</a>. Researchers can <a href="https://theconversation.com/forecasting-dead-zones-and-toxic-algae-in-us-waterways-a-bad-year-for-lake-erie-43747">forecast</a> these phenomena quite well and have calculated the nitrogen and phosphorus pollution cuts needed to reduce them. </p>
<p>These targets are now written into formal government commitments to clean up <a href="https://doi.org/10.1016/j.jglr.2016.09.007">Lake Erie</a>, the <a href="https://doi.org/10.1073/pnas.1705293114">Gulf</a> and the <a href="https://doi.org/10.1002/eap.2384">Chesapeake Bay</a>. Farmers and land owners nationwide received US$30 billion to support conservation, including practices designed to reduce water pollution, from <a href="https://www.ewg.org/news-insights/news-release/new-ewg-database-details-30-billion-spent-us-farm-conservation-programs">2005 to 2015</a>, and are scheduled to receive $60 billion more between <a href="https://crsreports.congress.gov/product/pdf/IF/IF12024#:%7E:text=Spending%20for%20agricultural%20conservation%20programs,are%20reauthorized%20with%20no%20changes.">2019 and 2028</a>. </p>
<p>But these efforts have fallen short, mainly because controls on nutrient pollution from agriculture are <a href="https://doi.org/10.3389/fmars.2019.00123">weak and ineffective</a>. In our view, there is no shortage of solutions to this problem. What’s needed is technological innovation and stronger political will. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing a zone with low oxygen values along the Louisiana coast." src="https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=299&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=299&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=299&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=376&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=376&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474157/original/file-20220714-32176-2cyi2q.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=376&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Gulf of Mexico hypoxic (dead) zone in 2021, which measured 6,334 square miles (16,400 square kilometers). Lower values represent less dissolved oxygen in the water.</span>
<span class="attribution"><a class="source" href="https://nrtwq.usgs.gov/nwqn/Sites/GULF_PRELIM/cruise2021-Final_2021_map_KM.jpg">Louisiana Universities Marine Consortium</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Problems return to Lake Erie</h2>
<p>State and federal agencies have known since the 1970s that overloading lakes and bays with nutrients generates huge blooms of algae. When the algae die and decompose, they deplete oxygen in the water, creating dead zones that can’t support aquatic life. But in each of these “big three” water bodies, efforts to curb nutrient pollution have been slow and halting. </p>
<p>The U.S., Canada and cities around Lake Erie started working to reduce phosphorus pollution in the lake from domestic and industrial wastes <a href="https://clevelandhistorical.org/items/show/58?tour=12&index=11">in 1972</a>. Water quality quickly improved, dead zones shrank and harmful algal blooms became less frequent. </p>
<p>But the scourges of <a href="https://doi.org/10.1016/j.jglr.2014.02.004">low-oxygen waters and sometimes-toxic algae</a> reappeared in the mid-1990s. This time, the source was mostly runoff from farm soils saturated with phosphorus from repeated applications of fertilizer and manure. Climate change made matters worse: Warmer waters hold less oxygen and <a href="https://blog.nature.org/science/2014/08/27/understanding-the-lake-erie-algal-bloom-toledo-water-shutdown/">cause faster growth of algae</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bar chart showing phosphorus entering Lake Erie 1967-2001." src="https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=324&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=324&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=324&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=407&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=407&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474182/original/file-20220714-33068-wgdrw3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=407&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Phosphorus loads to Lake Erie, 1967-2001. Nonpoint sources are wide areas without a distinct discharge point, such as farm fields.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1016/j.jglr.2014.02.004">Scavia et al., 2014</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Slow progress in the Chesapeake Bay</h2>
<p>Nitrogen and phosphorus reach the Chesapeake Bay from sources including wastewater treatment plants; air pollution emitters, such as factories and cars; and runoff from urban, suburban and agricultural lands. In 1987 the federal government and states around the bay agreed to reduce these flows by <a href="https://www.epa.gov/chesapeake-bay-tmdl/chesapeake-bay-agreements">40% by the year 2000</a> to restore water quality. But this effort relied on voluntary action and failed to make much progress. </p>
<p>In 2010 the states and the U.S. Environmental Protection Agency entered <a href="https://www.epa.gov/chesapeake-bay-tmdl/chesapeake-bay-tmdl-document">a legally binding commitment</a>, to reduce pollutant loads below prescribed maximum levels needed to restore water quality. If the states make inadequate progress, the EPA can limit or rescind their permitting authority, and the states may lose federal funding. </p>
<p>Nitrogen and phosphorus pollution has been <a href="https://www.chesapeakeprogress.com/clean-water/2017-watershed-implementation-plans">reduced</a> primarily by tightening permit requirements and upgrading wastewater treatment plants. Air pollution controls for power plants and vehicles have also reduced nitrogen reaching the bay. Water quality has improved, and the yearly dead zone has <a href="https://doi.org/10.1016/j.scitotenv.2021.152722">shrunk modestly</a>. </p>
<p>But with the commitment’s 2025 deadline nearing, nitrogen loads have been reduced by less then 50% of the targeted amounts, phosphorus by <a href="https://www.chesapeakebay.net/news/pressrelease/bay_program_model_shows_decline_in_nutrient_sediment_pollution_entering_the">less then 64%</a>. Most of the remaining pollution comes from <a href="https://doi.org/10.1002/jeq2.20101">farm runoff and urban stormwater</a>.
Intensifying agriculture in rural areas and sprawl in urban areas are counteracting other cleanup efforts. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Og4gYUR_m94?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Cleaning up water bodies with large watersheds, like the Chesapeake Bay (64,000 square miles/165,000 square kilometers, involves many states and thousands of pollution sources.</span></figcaption>
</figure>
<h2>Failure in the Gulf of Mexico</h2>
<p>The Gulf of Mexico dead zone forms every year during the summer, fueled by nutrients washing down the Mississippi River from Midwest farms. It <a href="https://www.noaa.gov/news-release/larger-than-average-gulf-of-mexico-dead-zone-measured">typically covers at least 6,000 square miles</a>, sometimes expanding up to 9,000 square miles (23,000 square kilometers), and affects an area very rich in fisheries. </p>
<p>In 2001, the EPA and 12 Mississippi River basin states agreed to take action to reduce the Gulf dead zone by two-thirds by 2015. Researchers estimated that this would require <a href="https://www.epa.gov/sites/default/files/2015-03/documents/2008_1_31_msbasin_sab_report_2007.pdf">reducing nitrogen loads reaching the Gulf by about 45%</a>, mostly from the Corn Belt. </p>
<p>Now that deadline has been <a href="https://www.epa.gov/sites/default/files/2015-10/documents/htf_report_to_congress_final_-_10.1.15.pdf">extended to 2035</a>. Nitrogen and phosphorus loadings at the mouth of the Mississippi River <a href="https://nrtwq.usgs.gov/nwqn/#/GULF">haven’t budged in 30 years</a>, so actions taken to date have <a href="https://www.epa.gov/ms-htf/history-hypoxia-task-force">failed to shrink the Gulf dead zone</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bar chart showing measurements of the Gulf of Mexico dead zone since 1985." src="https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474158/original/file-20220714-32145-o1yeg7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Since 2017 the Gulf of Mexico dead zone has covered an average of 5,380 square miles (14,000 square kilometers), which is 2.8 times larger than the 2035 target set by a federal task force.</span>
<span class="attribution"><a class="source" href="https://www.noaa.gov/news-release/larger-than-average-gulf-of-mexico-dead-zone-measured">LUMCON/NOAA</a></span>
</figcaption>
</figure>
<h2>Overwhelmed by agriculture</h2>
<p>In 2020, the EPA and Ohio <a href="https://epa.ohio.gov/static/Portals/35/tmdl/MaumeeNutrient/Maumee-Nutrient-TMDL-062022.pdf">adopted an agreement</a> similar to that for the Chesapeake to reduce phosphorus pollution below a prescribed maximum load from the Maumee River watershed at the western end of Lake Erie, where algal blooms occur most often. To date, Mississippi River basin states and even the EPA have <a href="https://doi.org/10.15779/Z38T727G2Q">opposed similarly mandating maximum pollution loads</a> to reduce the Gulf of Mexico dead zone. </p>
<p>Despite substantial government subsidies to implement various agricultural management practices, nitrogen and phosphorus pollution in streams in <a href="https://doi.org/10.1371/journal.pone.0195930">Iowa</a> and <a href="https://www2.illinois.gov/epa/topics/water-quality/watershed-management/excess-nutrients/Documents/NLRS-2021-Biennial-Report-FINAL.pdf">Illinois</a> has actually increased over the 1980-1996 baseline of the Gulf agreement. </p>
<p>Even with increasing crop yields and more efficient use of fertilizer, the expansion and intensification of agriculture in the Midwest has overwhelmed any water quality gains. One driver is ethanol production, which has increased <a href="https://www.eia.gov/todayinenergy/detail.php?id=36892">fortyfold</a> since the Gulf action plan was adopted in 2001. Today, over 40% of corn grown in the U.S. is <a href="https://www.ers.usda.gov/topics/crops/corn-and-other-feedgrains/feedgrains-sector-at-a-glance/">used for ethanol</a>, mostly in the Midwest, while most of the rest is used to feed animals. </p>
<p>In all three regions, the growth of large-scale livestock farms – <a href="https://www.vox.com/the-highlight/22344953/iowa-select-jeff-hansen-pork-farming">hogs in the Midwest</a>, <a href="https://www.delmarvanow.com/story/news/2021/10/29/84-poultry-operations-raised-water-pollution-concerns-yet-few-fined-report-environmental-watchdog/6180639001/">poultry around the Chesapeake Bay</a> – is also contributing to nutrient pollution. <a href="https://doi.org/10.1016/j.resconrec.2020.105065">Improper management of animal waste</a> adds to nitrogen and phosphorus loads in soils and local waters. </p>
<p>Studies show that agriculture contributes <a href="http://scavia.seas.umich.edu/wp-content/uploads/2018/02/Final-Report-Update-20160415.pdf">85% of Lake Erie’s Maumee River phosphorus load</a>, <a href="https://pubs.usgs.gov/circ/1486/cir1486.pdf">65% of the Chesapeake Bay’s nitrogen load</a> and 73.2% of the nitrogen load and 56% of the phosphorus load to the <a href="https://doi.org/10.1111/1752-1688.12905">Gulf of Mexico</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1223304943265648642"}"></div></p>
<h2>Incentives aren’t working</h2>
<p>We believe the evidence is clear that the largely voluntary approaches taken to date, with technical assistance and substantial public financing, are not working. </p>
<p>Economists have called for a <a href="https://doi.org/10.1111/1752-1688.13010">fundamental shift in policies controlling agricultural pollution</a>. Instead of offering polluters subsidies to clean up their operations, these experts argue, the strategy should be to pay farmers for performance, based on environmental outcomes that can be measured <a href="https://doi.org/10.13031/trans.12379">or predicted</a> at appropriate scales and specific places. </p>
<p>Under this approach, government would set limits on the amount of nutrients that can be lost to the environment, and farmers would choose how to meet them, based on what kinds of action work best for their specific soils and climate. For example, <a href="https://doi.org/10.1038/s41586-020-03042-5">restoring wetlands</a> within the watershed could help to capture nutrients that unavoidably wash off of farmlands. </p>
<p>The ongoing shift to electric vehicles offers an opportunity to grow far less grain for ethanol, which <a href="https://theconversation.com/the-us-biofuel-mandate-helps-farmers-but-does-little-for-energy-security-and-harms-the-environment-168459">doesn’t even help the climate</a>. And in the long run, developing <a href="https://www.scientificamerican.com/article/heres-how-much-food-contributes-to-climate-change/">efficient, plant-based food systems</a> would both reduce nutrient pollution and limit climate change. </p>
<p>In June 2022, the Government Accountability Office concluded that federal agencies charged with preventing and controlling harmful algal blooms and dead zones under a <a href="https://www.govinfo.gov/content/pkg/PLAW-105publ383/pdf/PLAW-105publ383.pdf">1998 law</a> have <a href="https://www.gao.gov/assets/gao-22-104449.pdf">failed to establish a national program</a> to address these issues. Fifty years after the federal Clean Water Act was enacted, we believe such a program is long overdue.</p><img src="https://counter.theconversation.com/content/186286/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Donald Boesch does not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article. He currently receives no external funding, but previously received funding from the National Science Foundation, Environmental Protection Agency, National Oceanic and Atmospheric Administration, and the Walton Family Foundation.</span></em></p><p class="fine-print"><em><span>Donald Scavia does not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article. He has received research funding from the National Science Foundation, Environmental Protection Agency, National Oceanic and Atmospheric Administration, and the Erb Family Foundation.</span></em></p>Nutrient pollution fouls lakes and bays with algae, killing fish and threatening public health. Progress curbing it has been slow, mainly because of farm pollution.Donald Boesch, Professor of Marine Science, University of Maryland Center for Environmental ScienceDonald Scavia, Professor Emeritus of Environment and Sustainability, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1807972022-07-10T07:20:35Z2022-07-10T07:20:35ZMorocco - a top fertiliser producer - could hold a key to the world’s food supply<figure><img src="https://images.theconversation.com/files/457076/original/file-20220408-25087-8s385g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Workers fill bags with fertiliser in Morocco's northern city of Meknes.</span> <span class="attribution"><span class="source">Photo by Fadel Senna/AFP via Getty Images</span></span></figcaption></figure><p>Morocco has a large fertiliser industry with huge production capacity and international reach. It is one of the world’s <a href="https://www.worldstopexports.com/top-fertilizers-exports-by-country/">top four</a> fertiliser exporters following Russia, China and Canada.</p>
<p>Fertilisers tend to divide into three main categories; nitrogen fertilisers, phosphorus fertilisers, potassium fertilisers. In 2020 the fertiliser market size <a href="https://www.gminsights.com/industry-analysis/fertilizer-market">was about</a> US$190 billion.</p>
<p>Morocco has distinct advantage in the production of phosphorus fertilisers. It possesses <a href="https://www.statista.com/statistics/681747/phosphate-rock-reserves-by-country/">over</a> 70% of the world’s phosphate rock reserves, from which the phosphorus used in fertilisers is derived. And this makes Morocco a gatekeeper of global food supply chains because all food crops require the element phosphorus to grow. Indeed, so does all plant life. Unlike other finite resources, such as fossil fuels, there is no alternative to phosphorus.</p>
<p>In 2021, the global phosphorus fertiliser market amounted to <a href="https://brandessenceresearch.com/chemical-and-materials/phosphate-fertilizers-market-size">about</a> US$59 billion. In Morocco, the sector’s 2020 revenues amounted to <a href="https://ocpsiteprodsa.blob.core.windows.net/media/2021-08/OCP-Sustainability_report_2020-GRI_certified.pdf">US$5.94 billion</a>. Office Chérifien des Phosphates, the producer owned by the Moroccan state, accounted for <a href="https://www.fitchratings.com/research/corporate-finance/fitch-revises-outlook-on-ocp-to-stable-affirms-at-bb-28-10-2020">about 20%</a> of the kingdom’s export revenues. It is also the country’s largest employer, providing jobs for <a href="https://ocpsiteprodsa.blob.core.windows.net/media/2021-08/OCP-Sustainability_report_2020-GRI_certified.pdf">21,000 people</a>. </p>
<p>Morocco plans to produce an additional 8.2 million tonnes of phosphorus fertiliser by 2026. <a href="https://www.mei.edu/publications/morocco-counters-russias-weaponization-food-energy-nexus">Currently production</a> is at about 12 million tonnes. </p>
<p>The state company recently <a href="https://medias24.com/2022/06/05/engrais-une-double-opportunite-pour-le-maroc/">announced</a> that it would increase its fertiliser production for the year by 10%. This would put an additional 1.2 million tonnes on the global market by the end of the year. This will significantly help markets.</p>
<p>But, as I argue in a <a href="https://www.mei.edu/publications/moroccos-new-challenges-gatekeeper-worlds-food-supply-geopolitics-economics-and">new report</a>, Morocco faces new challenges. Its production of fertiliser is threatened by increasingly daunting environmental and economic challenges. They include the COVID pandemic and the severe supply chain disruptions that have followed.</p>
<p>The timing to address these is crucial. </p>
<p>Russia is currently the world’s <a href="https://www.worldstopexports.com/top-fertilizers-exports-by-country/">largest</a> fertiliser exporter – 15.1% of total exported fertilisers. And fertiliser represents one of the greatest vulnerabilities for both Europe and Africa. For instance, the EU27 (all of the 27 member state of the European Union) as a whole depends on Russia for <a href="https://www.fao.org/3/ni972en/ni972en.pdf">30%</a> of its fertiliser supply. Russia’s advantageous position is amplified by its status as the world’s second-largest natural gas producer. Gas is a main component of all phosphorus fertilisers as well as nitrogen fertilisers.</p>
<p>Because of this, Russia’s invasion of Ukraine has serious implications for global food security. Both in terms of supply, and also because fertiliser can be used a economic weapon or tool.</p>
<p>Morocco could therefore become central to the global fertiliser market and a gatekeeper of the world’s food supply that could offset the attempt to use fertiliser as a weapon.</p>
<h2>The journey</h2>
<p>Morocco started to mine phosphorous in 1921. During the 1980s and 1990s it began to produce its own fertiliser. <a href="https://www.ocpgroup.ma/">Office Chérifien des Phosphates</a> built the world’s largest fertiliser production hub in Jorf Lasfar on Morocco’s Atlantic coast. </p>
<p>Before the outbreak of the Russia-Ukraine war, the company had over 350 clients on five continents. <a href="https://ocpsiteprodsa.blob.core.windows.net/media/2021-08/OCP-Sustainability_report_2020-GRI_certified.pdf">About</a> 54% of phosphate fertilisers bought in Africa come from Morocco. Moroccan fertilisers also account for major domestic market shares in India (50%), Brazil (40%) and Europe (41%). India and Brazil <a href="https://atlanticoonline.com/en/ocp-wants-to-expand-brazilian-operation-in-the-next-two-years/">have reached out</a> to Morocco to fill additional supply gaps.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471565/original/file-20220629-16-346qsh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Image from the OCP’s 2020 sustainability report.</span>
</figcaption>
</figure>
<p>Morocco’s economy has reaped the benefits of the transformation into an international fertiliser exporting giant. And in sub-Saharan Africa in particular, the combination of joint venture partnerships in local fertiliser production and <a href="https://ocpsiteprodsa.blob.core.windows.net/media/2020-10/Rapport%202020_EN_.pdf">direct outreach</a> to farmers has resulted in a <a href="https://ocpsiteprodsa.blob.core.windows.net/media/2020-10/Rapport%202020_EN_.pdf">remarkable boost</a> to African agricultural yields. </p>
<p>It’s also expanded Morocco’s soft power influence across the continent. For instance, Morocco <a href="https://www.worldfertilizer.com/project-news/15112019/ocp-group-expects-ammonia-plant-in-nigeria-to-begin-production-in-late-2023/">supplies over 90%</a> of Nigeria’s annual fertiliser demand. </p>
<p>But, how well Morocco manages challenges to the industry will affect both its own economic development and the stability of food supplies across the world. </p>
<h2>The challenges</h2>
<p><strong>Water and energy constraints</strong></p>
<p>Phosphate extraction and fertiliser production uses a lot of energy and water. Morocco’s phosphate and fertiliser industry <a href="https://www.theafricareport.com/413/mining-a-big-green-mining-machine/">consumes</a> about 7% of its annual energy output and 1% of its water. </p>
<p>But Morocco is among the countries <a href="https://www.unido.org/stories/responding-moroccos-water-challenge">suffering the most</a> from water scarcity. This is <a href="https://cedar.wwu.edu/cgi/viewcontent.cgi?article=1358&context=wwu_honors">due to</a> a dry climate, high water demand, climate change and reservoir contamination and siltation.</p>
<p>Morocco is trying to address this through a <a href="https://www.maroc.ma/en/news/head-government-2020-2050-national-water-plan-roadmap-face-challenges-next-30-years">National Water Plan 2020-2050</a>. It envisages building new dams and desalination plants and expanding irrigation networks, among other measures, to sustain agriculture and ecosystems. It’s <a href="https://www.maroc.ma/en/news/head-government-2020-2050-national-water-plan-roadmap-face-challenges-next-30-years">estimated to cost</a> about US$40 billion.</p>
<p><strong>Natural gas costs</strong></p>
<p>Nitrogen is the other basic fertiliser element that plants need. Diammonium phosphate, the most popular type of phosphorus fertiliser worldwide (and which Morocco makes along with monoammonium), is <a href="https://www.ocpgroup.ma/standard-fertilizers">composed of</a> 46% phosphorus and 18% nitrogen. Natural gas accounts for <a href="https://www.foodbusinessnews.net/articles/20163-high-fertilizer-prices-tight-supplies-may-adversely-affect-2022-acreage">at least 80%</a> of the variable cost of nitrogen fertiliser. </p>
<p>This means the price of natural gas massively affects production costs. But Morocco has scant natural gas resources. And natural gas prices have been soaring. </p>
<p>How well Morocco manages the food-water-energy nexus will affect both its own economic development and the stability of food supplies across the world. </p>
<h2>Some answers</h2>
<p>The key is to expand its renewable energy sector. Morocco holds <a href="https://www.bbc.com/future/article/20211115-how-morocco-led-the-world-on-clean-solar-energy">considerable</a> solar and wind resources. Fertiliser manufacturing could become powered by renewable energy, and renewable energy could be used within the fertiliser itself. </p>
<p>In 2020, the state’s fertiliser company covered <a href="https://www.moroccoworldnews.com/2022/06/349881/ocp-group-green-hydrogen-ammonia-is-the-future-of-energy">89%</a> of its energy needs by co-generation (producing two or more forms of energy from a single fuel source) and renewable energy sources. Its aim is to eventually cover 100% of its energy needs in this way. </p>
<p>Renewable energy could also be used within the fertiliser itself. Instead of importing ammonia derived from natural gas, Morocco could produce its own using hydrogen produced from its domestic renewable energy resources.</p>
<p>According to the state company, <a href="https://www.moroccoworldnews.com/2021/12/345902/ocp-reaffirms-commitment-to-investing-in-non-conventional-water-resources">31%</a> of its water needs are met with “unconventional” water resources, including treated wastewater and desalinated seawater. </p>
<p>Morocco’s growing reliance on desalination plants to satisfy industrial, agricultural and residential needs will require sizeable new investments in power generation from renewable energy sources. Desalination plants require <a href="https://www.frontiersin.org/articles/10.3389/frsc.2020.00009/full">10 times the amount of energy</a> to produce the same volume of water as conventional surface water treatment. </p>
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Read more:
<a href="https://theconversation.com/where-to-find-more-water-eight-unconventional-resources-to-tap-183681">Where to find more water: eight unconventional resources to tap</a>
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</em>
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<hr>
<p>To sustain operations and expand green ammonia production, Morocco will have to strike a careful balance between its fertiliser exports, its drive to expand its high-value agricultural exports and the provision of drinking water to its population.</p>
<p>Using its large solar energy resources to power green hydrogen and green ammonia production, along with desalination, Morocco could escape the vicious cycle of the upward spiralling of prices in the food-energy-water nexus.</p><img src="https://counter.theconversation.com/content/180797/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michaël Tanchum is an associate senior fellow in the Africa Programme at the European Council on Foreign Relations</span></em></p>How well Morocco manages challenges to its fertiliser industry will affect its own development and the stability of food supplies across the world.Michaël Tanchum, Senior Fellow at the Austrian Institute for European and Security Studies (AIES), non-resident fellow in the Economics and Energy Program at the Middle East Institute (MEI) and Professor, Universidad de NavarraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1834182022-06-14T12:30:35Z2022-06-14T12:30:35ZFertilizer prices are soaring – and that’s an opportunity to promote more sustainable ways of growing crops<figure><img src="https://images.theconversation.com/files/468526/original/file-20220613-11-9yinfb.jpg?ixlib=rb-1.1.0&rect=14%2C0%2C4905%2C3275&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A farmer spreads fertilizer on a field in Berks County, Pa.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/farmer-spreads-fertilizer-on-his-field-on-a-saturday-night-news-photo/1315197588">Harold Hoch/MediaNews Group/Reading Eagle via Getty Images</a></span></figcaption></figure><p>Farmers are coping with a <a href="https://www.fb.org/market-intel/too-many-to-count-factors-driving-fertilizer-prices-higher-and-higher">fertilizer crisis</a> brought on by soaring fossil fuel prices and industry consolidation. The price of synthetic fertilizer has more than <a href="https://www.agweb.com/news/crops/crop-production/fertilizer-prices-just-fell-30-one-day-farmers-saw-prices-skyrocket-133">doubled</a> since 2021, causing great stress in farm country. </p>
<p>This crunch is particularly tough on those who grow corn, which accounts for half of U.S. nitrogen fertilizer use. The National Corn Growers Association predicts that its members will <a href="https://www.regulations.gov/comment/AMS-AMS-22-0027-1349">spend 80% more in 2022 on synthetic fertilizers</a> than they did in 2021. A recent study estimates that on average, this will represent <a href="https://dt176nijwh14e.cloudfront.net/file/481/Study%20.pdf">US$128,000 in added costs per farm</a>.</p>
<p>In response, the Biden administration <a href="https://www.usda.gov/media/press-releases/2022/03/11/usda-announces-plans-250-million-investment-support-innovative">announced a new grant program</a> on March 11, 2022, “to support innovative American-made fertilizer to give U.S. farmers more choices in the marketplace.” The U.S. Department of Agriculture will invest <a href="https://www.dtnpf.com/agriculture/web/ag/news/business-inputs/article/2022/05/11/usda-aid-precision-ag-fertilizer">$500 million</a> to try to lower fertilizer costs by increasing production. But since this probably isn’t enough money to construct new fertilizer plants, it’s not clear how the money will be spent.</p>
<p>I direct the <a href="https://sustainability-innovation.asu.edu/food/">Swette Center for Sustainable Food Systems</a> at Arizona State University and have held senior positions at the USDA, including serving as deputy secretary of agriculture from 2009 to 2013. In my view, producing more synthetic fertilizer should not be the only answer to this serious challenge. The U.S. should also provide support for nature-based solutions, including farming practices that help farmers reduce or forgo synthetic fertilizers, and biological products that substitute for harsher chemical inputs.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/A8qTRBc8Bws?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Peas, beans and clover add nitrogen to soil naturally and can supplement or substitute for synthetic nitrogen fertilizer.</span></figcaption>
</figure>
<h2>Too much fertilizer in the wrong places</h2>
<p>All plants need nutrients to grow, especially the “big three” macronutrients: <a href="https://www.bhg.com/gardening/yard/garden-care/what-do-nitrogen-phosphorus-and-potassium-do/">nitrogen, phosphorus and potassium</a>. Farmers can fertilize their fields by planting <a href="https://tilthalliance.org/resources/how-legumes-fix-nitrogen-in-your-soil/">crops that add nitrogen to soil naturally</a> or by applying animal manure and compost to soil. </p>
<p>Since World War II, however, farmers have relied mainly on manufactured synthetic fertilizers that contain various ratios of nitrogen, phosphorus and potassium, along with secondary nutrients and micronutrients. That shift happened because manufacturers produced huge quantities of ammonium nitrate, the main ingredient in explosives, during the war; when the conflict ended, they <a href="https://cropwatch.unl.edu/fertilizer-history-p3">switched to making nitrogen fertilizer</a>.</p>
<p>Synthetic fertilizers have greatly enhanced crop yields and are rightly credited with <a href="https://www.unep.org/news-and-stories/story/fertilizers-challenges-and-solutions">helping to feed the world</a>. But they <a href="https://ourworldindata.org/reducing-fertilizer-use">aren’t used evenly around the world</a>. In poor regions like sub-Saharan Africa, too little fertilizer is available. In wealthier areas, abundant synthetic fertilizers have contributed to overapplication and serious <a href="https://theconversation.com/a-few-heavy-storms-cause-a-big-chunk-of-nitrogen-pollution-from-midwest-farms-146980">environmental harm</a>. </p>
<p>Excess fertilizer washes off of fields during storms and runs into rivers and lakes. There, it fertilizes huge blooms of algae that die and decompose, depleting oxygen in the water and creating “dead zones” that can’t support fish or other aquatic life. This process, <a href="https://oceanservice.noaa.gov/facts/eutrophication.html">eutrophication</a>, is a major problem in the <a href="https://www.canr.msu.edu/news/on_the_re_eutrophication_of_lake_erie">Great Lakes</a>, the <a href="https://mde.maryland.gov/programs/water/TMDL/TMDLImplementation/Pages/overview.aspx">Chesapeake Bay</a>, the <a href="https://www.noaa.gov/news-release/larger-than-average-gulf-of-mexico-dead-zone-measured">Gulf of Mexico</a> and <a href="https://www.usgs.gov/mission-areas/water-resources/science/nutrients-and-eutrophication">many other U.S. water bodies</a>. </p>
<p>Excess nitrogen can also contaminate drinking water and <a href="https://www.dhs.wisconsin.gov/publications/p02559.pdf">threaten human health</a>. And fertilizers, whether animal-sourced or synthetic, are a significant source of <a href="https://doi.org/10.1038/s41586-020-2780-0">nitrous oxide</a>, a potent greenhouse gas. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Green scum covers water around a dock." src="https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468499/original/file-20220613-12-kty283.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Heavy nutrient runoff from farmlands produces chronic blooms of algae in Lake Erie, the smallest Great Lake by volume.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/ejuTfh">NOAA</a></span>
</figcaption>
</figure>
<h2>What’s causing the crisis</h2>
<p>One reason U.S. fertilizer prices have spiked is that farmers are beholden to imports. COVID-19 disrupted supply chains, especially from China, a major fertilizer producer. And the war in Ukraine has cut off access to <a href="https://www.cropnutrition.com/resource-library/what-is-potash">potash</a>, an important potassium source, from Russia and Belarus. </p>
<p>Another factor is that the fertilizer industry is <a href="https://www.g20-insights.org/policy_briefs/promoting-competition-in-the-fertilizer-industry-and-efficiency-in-the-fertilizer-use-to-improve-land-productivity-and-sustainability/#_ftn4">highly concentrated</a>. There is little competition, so farmers have no choice but to buy fertilizer at the market price. Several U.S. state attorneys general have called on economists to study <a href="https://www.agweb.com/news/crops/crop-production/usda-attorney-generals-call-economists-study-soaring-fertilizer-costs">anti-competitive practices in the fertilizer industry</a>.</p>
<p>The USDA is seeking information on <a href="https://www.regulations.gov/document/AMS-AMS-22-0027-0001">competition and supply chain concerns in fertilizer markets</a> with a public comment deadline of June 15, 2022. But out of 66 specific questions the department posed with this request, only one addresses what I believe is the key issue: “How might USDA better support modes of production that rely less on fertilizer, or support access to markets that may pay a premium for products relying on less fertilizer?”</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1535263187288961026"}"></div></p>
<h2>Rethinking how to grow crops</h2>
<p>I see an opportunity for the Biden administration to take a fresh look at biological products as substitutes for synthetic fertilizers. This category includes <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/biofertilizer">biofertilizers and bionutrients</a> – natural materials that provide crop nutrition. Examples include microorganisms that extract nitrogen from the air and convert it into forms that plants can use, and fertilizers converted from manure, food and other plant and wood wastes. </p>
<p>Another category, <a href="https://www.bpia.org/solutions-provided-by-biological-products-biostimulants/">biostimulants</a>, comprises natural materials that enhance uptake of plant nutrients, reduce crop stress and increase crop growth and quality. Examples include algae and other plant extracts, microorganisms and <a href="https://soilbiotics.com/files/Humic_Acid_Explained.pdf">humic acids</a> – complex molecules produced naturally in soil when organic material breaks down.</p>
<p>In the past, critics dismissed natural products like these as “<a href="https://www.farmprogress.com/management/beware-snake-oil-fertilizers">snake oil</a>,” with little scientific evidence to show that they worked. Now, however, most experts believe that while <a href="https://doi.org/10.3389/fsufs.2021.606815">much remains to be learned</a>, current biofertilizers “offer huge potential in terms of <a href="https://doi.org/10.3389/fpls.2018.01473">new and more sustainable crop management practices</a>.” </p>
<p>Studies have demonstrated many benefits from these products. They include <a href="https://doi.org/10.3389/fmicb.2018.01606">less need for fertilizer</a>, <a href="https://doi.org/10.1007/s11104-014-2131-8">larger crop yields</a>, <a href="https://ucanr.edu/sites/CEStanislausCo/files/319748.pdf">enhanced soil health</a> and <a href="https://doi.org/10.1016/j.scitotenv.2021.148913">fewer carbon emissions</a>. </p>
<p>Large synthetic fertilizer companies like <a href="https://www.agweb.com/news/crops/crop-production/mosaic-eyes-expansion-biological-products">Mosaic</a>, <a href="https://www.ocpgroup.ma/press-release/ocp-sa-and-fertinagro-biotech-sl-announce-establishment-joint-venture-jorf-lasfar">OCP</a> and Nutrien are distributing, acquiring or investing in these biological technologies. Agribusiness giant Bayer has <a href="https://www.wired.com/story/farmers-can-now-buy-designer-microbes-to-replace-fertilizer/">partnered with Ginkgo Bioworks</a> in a joint venture called <a href="https://joynbio.com/about">Joyn</a> whose mission is creating “sustainable ag biologicals for crop protection and fertility that meet or exceed the performance of their chemical counterparts.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&rect=50%2C0%2C5568%2C3709&q=45&auto=format&w=1000&fit=clip"><img alt="A hand spreads pellets and crushed rock over dirt." src="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&rect=50%2C0%2C5568%2C3709&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A farmer spreads two types of organic fertilizers – bone meal pellets and rock phosphate – before planting spinach in Golden, Colo.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/david-wann-spreads-organic-fertilizers-bone-meal-pellets-news-photo/649873342">Joe Amon/The Denver Post via Getty Images</a></span>
</figcaption>
</figure>
<h2>Offering more choices</h2>
<p>Panicked U.S. farmers facing daunting fertilizer prices are looking for options. In public comments on USDA’s fertilizer initiative, the <a href="https://www.regulations.gov/comment/AMS-AMS-22-0027-1064">Illinois Corn Growers Association</a> urged the department to investigate why farmers apply fertilizers at levels higher than necessary, while others noted a shortage of agronomists sufficiently trained to guide farmers on how best to sustainably fertilize their crops. </p>
<p>I believe now is an opportune time for USDA to offer incentives for adopting biologicals, as well as practices that organic farmers use to replace synthetic fertilizers, such as <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/programs/?cid=nrcs142p2_044349">crop rotation</a>, <a href="http://cwmi.css.cornell.edu/composting.htm">composting</a> and <a href="https://www.csuchico.edu/regenerativeagriculture/ra101-section/integrating-livestock.shtml">raising crops and livestock together</a>. A first step would be to deploy technicians who can advise farmers about sustainable practices and biological products. The department recently announced a new $300 million initiative to <a href="https://www.usda.gov/media/press-releases/2022/06/01/usda-announces-framework-shoring-food-supply-chain-and-transforming">help farmers transition to organic production</a>; this is the right idea, but more help is needed. </p>
<p>The agency could also provide one-time payments to farmers in exchange for reducing their use of synthetic fertilizers, which would help to compensate them as they shift their production methods. In the longer term, I believe the USDA should develop new crop insurance tools to protect farmers from the risks of transitioning to more sustainable options. In my view, this kind of broad response would yield more value than a taxpayer-funded, status quo approach to synthetic fertilizers.</p><img src="https://counter.theconversation.com/content/183418/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kathleen Merrigan worked for six years at the US Department of Agriculture, most recently serving as Deputy Secretary of Agriculture from 2009-2013. She is a venture partner at Astanor Ventures, a European-based agtech firm that invests in a wide range of innovations, including in the biocontrol/biostiumulant sector. She previously served on the board of directors of Marrone Bio Innovations and holds stock in the company. </span></em></p>Farmers are contending with huge spikes in fertilizer prices. The Biden administration is paying US companies to boost synthetic fertilizer production, but there are other, more sustainable options.Kathleen Merrigan, Executive Director, Swette Center for Sustainable Food Systems, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1810372022-05-19T12:23:07Z2022-05-19T12:23:07ZRestoring the Great Lakes: After 50 years of US-Canada joint efforts, some success and lots of unfinished business<figure><img src="https://images.theconversation.com/files/464009/original/file-20220518-11-qy3i71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4000%2C2311&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Children participate in a water fight in Lake Ontario in Mississauga, Ontario, during a heat wave on June 5, 2021. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/children-have-a-water-fight-at-lake-ontario-in-mississauga-news-photo/1233295324">Zou Zheng/Xinhua via Getty Images</a></span></figcaption></figure><p>The Great Lakes cover <a href="https://theconversation.com/the-impulse-to-garden-in-hard-times-has-deep-roots-137223">nearly 95,000 square miles</a> (250,000 square kilometers) and hold over 20% of Earth’s surface fresh water. <a href="https://coast.noaa.gov/states/fast-facts/great-lakes.html">More than 30 million people</a> in the U.S. and Canada rely on them for drinking water. The lakes support a multibillion-dollar maritime economy, and the lands around them provided many of the raw materials – timber, coal, iron – that fueled the Midwest’s emergence as an industrial heartland.</p>
<p>Despite their enormous importance, the lakes were <a href="https://www.ijc.org/en/great-lakes-1972-water-quality-agreement">degraded for well over a century</a> as industry and development expanded around them. By the 1960s, rivers like the Cuyahoga, Buffalo and Chicago were so polluted that they were <a href="https://www.environmentalcouncil.org/when_our_rivers_caught_fire">catching fire</a>. In 1965, Maclean’s magazine called Lake Erie, the smallest and shallowest Great Lake, “<a href="https://archive.macleans.ca/article/1965/11/1/death-of-a-great-lake">an odorous, slime-covered graveyard</a>” that “may have already passed the point of no return.” Lake Ontario <a href="https://scholar.uwindsor.ca/cgi/viewcontent.cgi?article=1012&context=ijcarchive">wasn’t far behind</a>.</p>
<p>In 1972, the U.S. and Canada signed the <a href="https://www.ijc.org/sites/default/files/C23.pdf">Great Lakes Water Quality Agreement</a>, a landmark pact to clean up the Great Lakes. Now, 50 years later, they have made progress, but there are new challenges and much unfinished business. </p>
<p>I <a href="https://scholar.google.com/citations?user=G4RniBIAAAAJ&hl=en">study the environment</a> and have written four books on U.S.-Canadian management of their shared border waters. In my view, the Great Lakes Water Quality Agreement was a watershed moment for environmental protection and an international model for regulating transboundary pollution. But I believe the people of the U.S. and Canada failed the Great Lakes by becoming complacent too soon after the pact’s early success. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of the Great Lakes-St. Lawrence Basin" src="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=557&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Great Lakes-St Lawrence River Basin spans nearly half of North America, from northern Minnesota to New England.</span>
<span class="attribution"><a class="source" href="https://www.ijc.org/en/watersheds/great-lakes">International Joint Commission</a></span>
</figcaption>
</figure>
<h2>Starting with phosphates</h2>
<p>A major step in Canada-U.S. joint management of the Great Lakes came in 1909 when they signed the <a href="https://www.ijc.org/en/boundary-waters-treaty-1909">Boundary Waters Treaty</a>. The Great Lakes Water Quality Agreement built on this foundation by creating a framework to allow the two countries to cooperatively restore and protect these border waters. </p>
<p>However, as an executive agreement, rather than a formal government-to-government treaty, the pact has no legal mechanisms for enforcement. Instead, it relies on the U.S. and Canada to fulfill their commitments. The <a href="https://www.ijc.org/en/who/role">International Joint Commission</a>, an agency created under the Boundary Waters Treaty, carries out the agreement and tracks progress toward its goals. </p>
<p>The agreement set common targets for controlling a variety of pollutants in Lake Erie, Lake Ontario and the upper St. Lawrence River, which were the most polluted section of the Great Lakes system. One key aim was to reduce nutrient pollution, especially phosphates from detergents and sewage. These chemicals fueled huge blooms of algae that then died and decomposed, depleting oxygen in the water. </p>
<p>Like national water pollution laws enacted at the time, these efforts focused on point sources – pollutants released from discreet, readily identifiable points, such as discharge pipes or wells.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of the Great Lakes and connecting water bodies in profile." src="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=250&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=250&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=250&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=314&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=314&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=314&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This profile view of the Great Lakes shows that Lake Erie is much shallower than the other lakes. As a result, its waters warm faster and are more vulnerable to algal blooms.</span>
<span class="attribution"><a class="source" href="https://twitter.com/NOAA_GLERL/status/1270022370640658437/photo/1">NOAA</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Early results were encouraging. Both governments invested in new sewage treatment facilities and convinced manufacturers to <a href="https://www.nytimes.com/1970/05/03/archives/detergents-listed-in-phosphate-order.html">reduce phosphate loads in detergents and soaps</a>. But as phosphorus levels in the lakes declined, scientists soon detected other problems.</p>
<h2>Toxic contaminants</h2>
<p>In 1973, scientists reported a perplexing find in fish from Lake Ontario: <a href="http://dx.doi.org/%2010.1126/science.185.4150.523">mirex, a highly toxic organochloride pesticide</a> used mainly to kill ants in the southeast U.S. An investigation revealed that the <a href="https://www.nytimes.com/1976/09/03/archives/new-jersey-pages-chemical-flowing-illegally-into-niagara-toxic.html">Hooker Chemical company</a> was discharging mirex from its plant in Niagara Falls, New York. The contamination was so severe that New York State <a href="https://aliciapatterson.org/stories/northern-fish-mystery">banned eating popular types of fish</a> such as coho salmon and lake trout from Lake Ontario from 1976 to 1978, shutting down commercial and sport fishing in the lake. </p>
<p>In response to this and other findings, the U.S. and Canada updated the Great Lakes Water Quality Agreement in 1978 to cover all five lakes and focus on chemicals and toxic substances. This version formally adopted an <a href="https://ijc.org/sites/default/files/2019-05/WQB_PracticalStepstoImplementanEcosystemApproachinGreatLakesManagement_December1995.pdf">ecosystem approach</a> to pollution control that considered interactions between water, air and land – perhaps the first international agreement to do so. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/gBRcOLcEwF0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A tour of the Great Lakes and the nature in and around them.</span></figcaption>
</figure>
<p>In 1987, the two countries identified <a href="https://www.ijc.org/en/what/glwq-aoc">the most toxic hot spots</a> around the lakes and adopted action plans to clean them up. However, as <a href="https://press.ucalgary.ca/books/9781552388952/">scholars</a> of North American environmental regulations <a href="https://press.uchicago.edu/ucp/books/book/chicago/M/bo3629140.html">acknowledge</a>, both nations too often allowed industries to police themselves. </p>
<p>Since the 1990s, <a href="https://www.dec.ny.gov/data/DecDocs/932121/Report.HW.932121.2009-03-26.ToxicsChemicalsInTributariesToLakeOntario.pdf">studies</a> have identified toxic pollutants including <a href="https://doi.org/10.1021/acs.estlett.8b00019">PCBs</a>, <a href="https://doi.org/10.1016/j.envint.2020.106065">DDT</a> and chlordane in and around the Great Lakes, as well as lead, copper, arsenic and others. Some of these chemicals <a href="https://doi.org/10.1021/es501509r">continued to show up</a> because they were persistent and took a long time to break down. Others were banned but leached from contaminated sites and sediments. Still others came from a range of point and nonpoint sources, including <a href="https://www.ijc.org/sites/default/files/D9.pdf">many industrial sites</a> concentrated on shorelines.</p>
<p>Many hazardous sites have been slowly cleaned up. However, toxic pollution in the Great Lakes <a href="https://www.regions.noaa.gov/great-lakes/index.php/great_lakes-restoration-initiative/toxics/">remains a colossal problem</a> that is largely unappreciated by the public, since these substances don’t always make the water look or smell foul. Numerous <a href="https://ehp.niehs.nih.gov/doi/10.1289/ehp104">fish advisories</a> are still in effect across the region because of chemical contamination. Industries constantly bring new chemicals to market, and <a href="https://www.pbs.org/newshour/science/it-could-take-centuries-for-epa-to-test-all-the-unregulated-chemicals-under-a-new-landmark-bill">regulations lag far behind</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1004722065247698944"}"></div></p>
<h2>Nonpoint sources</h2>
<p>Another major challenge is <a href="https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution">nonpoint source pollution</a> – discharges that come from many diffuse sources, such as runoff from farm fields. </p>
<p><a href="https://doi.org/10.1086/684646">Nitrogen levels</a> in the lakes have risen significantly because of agriculture. Like phosphorus, nitrogen is a nutrient that causes large blooms of algae in fresh water; it is one of the main ingredients in fertilizer, and is also found in human and animal waste. <a href="https://greatlakes.org/campaigns/sewage-overflows/">Sewage overflows</a> from cities and <a href="https://elpc.org/blog/the-great-lakes-cafos-and-water-quality/">waste and manure runoff</a> from industrial agriculture carry heavy loads of nitrogen into the lakes.</p>
<p>As a result, algal blooms have <a href="https://www.glerl.noaa.gov/res/HABs_and_Hypoxia/bulletin.html">returned to Lake Erie</a>. In 2014, toxins in one of those blooms forced officials in Toledo, Ohio, to <a href="https://greatlakes.org/2019/08/five-years-later-lessons-from-the-toledo-water-crisis/">shut off the public water supply</a> for half a million people. </p>
<p>One way to address nonpoint source pollution is to set an overall limit for releases of the problem pollutant into local water bodies and then work to bring discharges down to that level. These measures, known as <a href="https://www.epa.gov/tmdl/overview-total-maximum-daily-loads-tmdls">Total Maximum Daily Loads</a>, have been applied or are in development for parts of the Great Lakes basin, including <a href="https://greatlakes.org/2020/02/statement-development-of-a-pollution-diet-for-western-lake-erie/">western Lake Erie</a>.</p>
<p>But this strategy relies on states, along with <a href="https://www.freshlawblog.com/2016/06/02/us-epas-great-lakes-restoration-initiative-grants-for-voluntary-action-a-striking-contrast-to-the-chesapeake-bay-tmdl/">voluntary steps by farmers</a>, to curb pollution releases. Some Midwesterners would prefer a regional approach like the strategy for Chesapeake Bay, where states asked the U.S. government to write a sweeping <a href="https://www.chesapeakebay.net/what/programs/total_maximum_daily_load">federal TMDL for key pollutants</a> for the bay’s entire watershed.</p>
<p>In 2019, Toledo voters adopted a <a href="https://theconversation.com/how-giving-legal-rights-to-nature-could-help-reduce-toxic-algae-blooms-in-lake-erie-115351">Lake Erie Bill of Rights</a> that would have permitted citizens to sue when Lake Erie was being polluted. Farmers <a href="https://www.michiganradio.org/environment-science/2020-02-28/lake-erie-bill-of-rights-declared-unconstitutional">challenged the measure in court</a>, and it was declared unconstitutional.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CdmlEGTMwkA/?utm_source=ig_web_copy_link","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Warming and flooding</h2>
<p><a href="https://nca2018.globalchange.gov/chapter/21/">Climate change</a> is now complicating Great Lakes cleanup efforts. Warmer water can affect oxygen concentrations, nutrient cycling and food webs in the lakes, potentially <a href="https://theconversation.com/warmer-wetter-wilder-38-million-people-in-the-great-lakes-region-are-threatened-by-climate-change-170195">intensifying problems</a> and converting nuisances into major challenges. </p>
<p>Flooding driven by climate change threatens to <a href="https://theconversation.com/climate-change-threatens-drinking-water-quality-across-the-great-lakes-131883">contaminate public water supplies</a> around the lakes. Record-high water levels are <a href="https://theconversation.com/great-lakes-flooding-the-warning-signs-that-homes-must-be-moved-122697">eroding shorelines and wrecking infrastructure</a>. And new problems are emerging, including <a href="https://www.greatlakesnow.org/2021/05/chemical-impact-microplastic-pollution/">microplastic pollution</a> and “forever chemicals” such as <a href="https://news.wisc.edu/study-finds-tributaries-play-significant-role-in-great-lakes-pfas-loading/">PFAS and PFOA</a>. </p>
<p>It will be challenging for the U.S. and Canada to make progress on this complex set of problems. Key steps include prioritizing and funding cleanup of toxic zones, finding ways to halt agricultural runoff and building new sewer and stormwater infrastructure. If the two countries can muster the will to aggressively tackle pollution problems, as they did with phosphates in the 1970s, the Great Lakes Water Quality Agreement gives them a framework for action.</p><img src="https://counter.theconversation.com/content/181037/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Macfarlane has received funding from the Social Sciences and Humanities Research Council and Western Michigan University. </span></em></p>Cleaning up the Great Lakes was a big job when the US and Canada undertook it in 1972. Today it’s far more challenging.Daniel Macfarlane, Associate Professor of Environment and Sustainability, Western Michigan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1697732021-10-20T13:53:55Z2021-10-20T13:53:55ZPhosphorites: mineral-rich rocks offer insight into ancient Namibian ecosystems<figure><img src="https://images.theconversation.com/files/426911/original/file-20211018-27-f2ry5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Namibian phosphorite isn't just beautiful: it holds secrets from the past.</span> <span class="attribution"><span class="source">Eugene Bergh</span></span></figcaption></figure><p>Minerals are an important part of our everyday lives. They’re in the <a href="https://www.nms.ac.uk/explore-our-collections/resources/from-minerals-to-your-mobile/">mobile phones</a> we use, the cars we drive and even in <a href="https://medlineplus.gov/minerals.html">the food we eat</a>.</p>
<p>Phosphorus is a mineral with many uses. It is extracted from rocks called phosphorites and used in fertiliser, animal feed, as a food additive, in detergents and in herbicides, as well as in various other industries. But it can also be useful in an entirely different way: to help scientists learn more about how our climate, the oceans and the environment have changed over long periods of time.</p>
<p>Southern Africa is an important region for phosphorite mining. As a geologist, I have spent years studying the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0025322716300524">phosphorite deposits</a> of southern Africa, particularly those of offshore Namibia, to gain a better understanding of how they form and how they are related to both past and modern environments, and map their changes.</p>
<p>Studying these deposits gives scientists information about how past environments change. That, in turn, gives us informed estimates on how climates and environments will change in the near future. This is important for the sustainability of our lives, environments and the ecosystems we depend on. </p>
<h2>Namibian deposits</h2>
<p>Phosphorites form in different ways. Some are sedimentary – they form from pre-existing sediments that are cemented together over time and harden, or they precipitate from a pre-existing source. Others are igneous, meaning the rocks form from volcanic or magmatic activity. Guano deposits are another source of phosphate, either through cave deposits where bat droppings accumulate or from the accumulation of bird droppings. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=590&fit=crop&dpr=1 600w, https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=590&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=590&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=742&fit=crop&dpr=1 754w, https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=742&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/426895/original/file-20211018-20-rrw5ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=742&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Components extracted from the phosphorite layers.</span>
<span class="attribution"><span class="source">John Compton</span></span>
</figcaption>
</figure>
<p>Rising demand for phosphate, amid decreasing reserves of this non-renewable resource, <a href="https://cer.org.za/wp-content/uploads/2016/08/Assessing-the-Desirability-of-Marine-Phosphate-WEB.pdf">piqued interest</a> in southern Africa’s extensive offshore phosphorite deposits during the first decade of the 21st century.</p>
<p>The Namibian phosphorites are <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/phosphorite">marine sedimentary</a>; they are brown to black and look either like sand-sized grains, small pebbles or rock fragments. They’re found with <a href="https://www.researchgate.net/publication/342294335_Quaternary_foraminifera_and_mollusc_assemblages_on_the_southwestern_African_shelf">fossil material</a>, such as whale bone, fish bone, the remains of sponges and echinoids (sea urchins), bivalves (such as clams), marine gastropods (sea snails), as well as the fossils of small marine organisms, called ostracods and foraminifera.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=546&fit=crop&dpr=1 600w, https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=546&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=546&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=686&fit=crop&dpr=1 754w, https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=686&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/426912/original/file-20211018-15-krohfl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=686&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some phosphorite layers contain shell material and the fossilised remains of marine organisms called foraminifera. The numerous black grains are pelletal phosphorite.</span>
<span class="attribution"><span class="source">Eugene Bergh</span></span>
</figcaption>
</figure>
<p>The offshore Namibian phosphorites started forming 7 million years ago. <a href="https://www.researchgate.net/publication/342294335_Quaternary_foraminifera_and_mollusc_assemblages_on_the_southwestern_African_shelf">The deposits</a> in which these phosphorites are found can tell us a great deal about how the marine environments along western southern Africa have changed since then.</p>
<p>I looked at the internal structures of these phosphorites under a microscope. This revealed concentric bands that may represent different episodes and repeated cycles of formation at different ages. Many of the phosphorite grains also contained the remnants of fossil material or other minerals (such as quartz and glauconite) in the centre of its structure. This means that the phosphate precipitated from or grew around the non-phosphatic nucleus. </p>
<p>So, how did these deposits form? </p>
<h2>Formation</h2>
<p>Between 5 and 7 million years ago, the <a href="https://www.benguelacc.org/index.php/en/activities/2016-12-13-09-13-15/ebsas-in-the-bclme/benguela-upwelling-system">Benguela Upwelling System</a>, a highly productive marine system that runs along the western ocean of southern Africa, began off Namibia. Upwelling is the process where sea surface waters are replaced by colder, nutrient-rich water from below, and the Benguela Upwelling is regarded as one of the world’s most productive upwelling systems. This means that there is a high amount of organic matter available to support a functioning marine ecosystem. </p>
<p>The age of the initiation of the Benguela Upwelling System is consistent with the oldest offshore phosphorites found in the area. The later, higher concentration of phosphorites that are younger than 5 million years old indicates the intensification of upwelling along Namibia’s ocean margin. </p>
<p>Upwelling delivered phosphorous to the surface waters; the mineral was taken up by marine primary producers – organisms in the ocean that convert light and chemical energy into their food source – and delivered again to the seafloor as these organisms died. Microbial activity on the sea floor released more phosphorus, which created supersaturated conditions that led to the formation of phosphorus-rich minerals. This repeated cycling caused the phosphorus-enrichment in these marine deposits.</p>
<p>The fossils mixed in with the phosphorites reveal that the region’s climate started shifting around this time: sea levels dropped as the ocean became colder and upwelling intensified. The fossils that have been found with the phosphorites indicate that marine fauna that adapted to warmer waters became fauna that were adapted to shallower water depths and ocean conditions that became colder. This is also consistent with fossils and marine terraces that <a href="https://www.dailymaverick.co.za/article/2020-09-28-south-african-seas-up-to-30m-higher-show-a-wet-planet-under-siege/">have been found on-shore</a>. </p>
<p>These fossils and geologic structures indicate that the sea level was much higher 3 million years ago and gradually lowered with time. This was also a time period in which the carbon dioxide levels were at similar levels as they are today. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Fossil shells (numbers 1-4) and microfossils (numbers 5-7) found in the phosphatic layers." src="https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/426905/original/file-20211018-18-1cls7by.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fossil shells (numbers 1-4) and microfossils (numbers 5-7) found in the phosphatic layers, which supported the environmental indicators of the phosphorite.
1. Dosinia lupinus (bivalve); 2. Lucinoma capensis (bivalve); 3. Nassarius vinctus (gastropod); 4. Turritella declivis (gastropod); 5. Ammonia batava (foraminifer); 6. Elphidium advenum (foraminifer); 7. Uvigerina peregrina (foraminifer).</span>
<span class="attribution"><span class="source">Eugene Bergh</span></span>
</figcaption>
</figure>
<h2>Important information</h2>
<p>This is a good example of why scientists study ancient environments. By knowing what happened when carbon dioxide levels increased millions of years ago – in the case of Namibia and South Africa, higher sea levels – we can determine how environments change with these types of conditions. The marine environments in which phosphorites are found can therefore provide us with important information on past, current and future climate and environmental change.</p><img src="https://counter.theconversation.com/content/169773/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eugene Bergh receives funding from the National Research Foundation South Africa. </span></em></p>Studying these deposits gives scientists information about how past environments change. That, in turn, gives us informed estimates on how climates and environments will change in the near future.Eugene Bergh, Research Scientist, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1585682021-04-08T17:48:03Z2021-04-08T17:48:03ZWater being pumped into Tampa Bay could cause a massive algae bloom, putting fragile manatee and fish habitats at risk<figure><img src="https://images.theconversation.com/files/393869/original/file-20210407-17-brnypt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tampa Bay's sea grass meadows need sunlight to thrive. Algae blooms block that light and can be toxic to marine life.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/btsAoomBCeM">Joe Whalen Caulerpa/Tampa Bay Estuary Program via Unsplash</a></span></figcaption></figure><p>Millions of gallons of water laced with fertilizer ingredients are being pumped into Florida’s Tampa Bay from a <a href="https://protectingfloridatogether.gov/PineyPointUpdate">leaking reservoir</a> at an abandoned phosphate plant at Piney Point. As the water spreads into the bay, it carries phosphorus and nitrogen – nutrients that under the right conditions can <a href="https://www.noaa.gov/what-is-harmful-algal-bloom">fuel dangerous algae blooms</a> that can suffocate sea grass beds and kill fish, dolphins and manatees.</p>
<p>It’s the kind of risk no one wants to see, but officials believed the other options were worse.</p>
<p>About 300 homes sit downstream from the 480-million-gallon reservoir, which began leaking in late March 2021. State officials determined that <a href="https://protectingfloridatogether.gov/PineyPointUpdate">pumping out the water</a> was the only way to prevent the reservoir’s walls from collapsing. They decided the safest location for all that water would be out <a href="https://www.usatoday.com/in-depth/news/2021/04/05/piney-point-florida-reservoir-breach-flood-tampa-bay-palmetto-evacuation/7088307002/">through Port Manatee</a> and into the bay.</p>
<p>Florida’s coast is dotted with <a href="https://www.fws.gov/southeast/gulf-restoration/next-steps/focal-area/tampa-bay/">fragile marine sanctuaries</a> and <a href="https://www.pewtrusts.org/en/research-and-analysis/issue-briefs/2019/10/healthy-seagrass-forms-underwater-meadows-that-harbor-diverse-marine-life">sea grass beds</a> that help nurture the state’s thriving <a href="https://coast.noaa.gov/enowexplorer/#/employment/total/2017/12081">marine and tourism economy</a>. Those near Port Manatee now face a risk of algal blooms over the next few weeks. Once algae blooms get started, little can be done to clean them up.</p>
<p>The phosphate mining industry around Tampa is just one source of nutrients that can fuel dangerous algae blooms, which I study <a href="https://people.miami.edu/profile/l.brand@miami.edu#panelResearch">as a marine biologist</a>. The sugarcane industry, cattle ranches, dairy farms and citrus groves <a href="https://iwaponline.com/wp/article/20/5/919/41575">all release</a> <a href="http://doi.org/10.1016/j.hal.2006.08.005">nutrients</a> that often flow into rivers and eventually into bays and the ocean. Sewage is another problem – Miami and Fort Lauderdale, for example, have <a href="https://www.theguardian.com/us-news/2020/sep/10/florida-sewage-spill-waterways-infrastructure">old sewage treatment systems with frequent pipe breaks</a> that leak sewage into canals and coastal waters.</p>
<p>All can <a href="https://iwaponline.com/wp/article/20/5/919/41575">fuel harmful algal blooms</a> that harm marine life and people. Overall, blooms are <a href="https://www.jstor.org/stable/24897842">getting worse locally</a> and <a href="https://doi.org/10.1038/s41586-019-1648-7">globally</a>. </p>
<figure class="align-center ">
<img alt="Two manatees swimming underwater" src="https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/394065/original/file-20210408-21-19rm9jk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Red tide in recent years has killed large numbers of Florida’s manatees, a threatened species.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/usfwsendsp/5104977481/">David Hinkel/U.S. Fish and Wildlife Service</a></span>
</figcaption>
</figure>
<h2>The problem with algae blooms</h2>
<p>Just down the coast from Port Manatee, the next three counties to the south have had algae blooms in recent weeks, including red tide, which <a href="https://doi.org/10.1016/j.hal.2009.08.005">produces a neurotoxin</a> that feels like pepper spray if you breathe it in. <em>Karenia brevis</em>, a dinoflagellate, is the organism in red tide and produces the toxin.</p>
<p>This part of Florida’s Gulf Coast is a <a href="https://doi.org/10.1016/j.hal.2006.08.005">hot spot for red tide</a>, often fueled by agricultural runoff. A persistent red tide in 2017 and 2018 <a href="https://wusfnews.wusf.usf.edu/2020-01-02/2019-was-not-a-good-year-for-manatees-boat-strikes-and-red-tide-took-a-toll">killed at least 177 manatees</a> and left a trail of dead fish along the coast and into Tampa Bay. If the coastal currents carry today’s red tide father north and into Tampa Bay, the toxic algae could thrive on the nutrients from Piney Point. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two maps with dots showing locations of reports." src="https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=270&fit=crop&dpr=1 600w, https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=270&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=270&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/394043/original/file-20210408-13-1dg5rae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A map shows red tide reports just south of Tampa Bay.</span>
<span class="attribution"><a class="source" href="https://myfwc.com/research/redtide/statewide/">Florida Fish and Wildlife Conservation Commission</a></span>
</figcaption>
</figure>
<p>Even blooms that are not toxic are <a href="https://www.noaa.gov/what-is-harmful-algal-bloom">still dangerous to ecosystems</a>. They cloud the water, cutting off light and killing the plants below. A large enough bloom can also reduce oxygen in the water. A lack of oxygen can kill off everything in the water, including the fish.</p>
<p>This part of Florida has extensive sea grass meadows, <a href="https://floridadep.gov/rcp/seagrass">about 2.2 million acres (8.9 billion square meters) in all</a>, which are important habitat for lots of species and serve as nurseries for shrimp, crabs and fish. Scientists have argued that sea grass is also a <a href="https://doi.org/10.1038/ngeo1477">major carbon sink</a> – the grass sucks up carbon and pumps it down into the sediments.</p>
<p>Once the nutrients are in a large body of water, there isn’t much that can be done to stop algae growth. Killing the algae would only release the nutrients again, putting the bay back where it started. Algae blooms can remain a problem for years, finally declining when a predator population develops to eats them, a viral disease spreads through the bloom or strong currents and mixing disperse the bloom.</p>
<h2>Agriculture runoff poses risks to marine life</h2>
<p>The phosphate mining industry around Tampa is a large source of nutrient-rich waste. On average, <a href="https://www.epa.gov/radiation/tenorm-fertilizer-and-fertilizer-production-wastes#fertilizer">more than 5 tons</a> of phosphogypsum waste are produced for every ton of phosphoric acid created for fertilizer. In Florida, that adds up to <a href="https://fipr.floridapoly.edu/about-us/phosphate-primer/phosphogypsum-stacks.php">over 1 billion tons</a> of radioactive waste material that can’t be used, so it’s stacked up and turned into reservoirs like the one now leaking at Piney Point.</p>
<p>The reservoirs are obvious in satellite photos of the region, and they can be highly acidic. To get the phosphate out of the minerals, the industry uses sulfuric acid, and it leaves behind a highly acid wastewater. There have been at least <a href="https://www.theguardian.com/us-news/2016/sep/17/florida-sinkhole-wastewater-leak-drinking-water">two cases where it ate through the limestone below a reservoir</a>, creating huge sinkholes hundreds of feet deep and draining wastewater into the aquifer.</p>
<p>Since <a href="https://protectingfloridatogether.gov/PineyPointUpdate">saltwater had previously been pumped into</a> the Piney Point reservoir, acidity is less of an issue. That’s because the seawater would buffer the pH. There is some radioactivity, but <a href="https://protectingfloridatogether.gov/PineyPointUpdate">only slightly above regulatory standards</a>, according to state Department of Environmental Protection, and probably not much of a health hazard.</p>
<p>But the nutrients are a risk. In 2004, water releases from the Piney Point reservoir <a href="https://www.wtsp.com/article/news/local/piney-point-dumping-causes-algae-bloom-in-bishop-harbor/67-396514258">contributed to an algae bloom</a> in Bishop Harbor, just south of the current release site. In 2011, it released over <a href="https://thebradentontimes.com/piney-point-a-retrospective-p6328-158.htm">170 million gallons</a> into Bishop Harbor again after a liner broke.</p>
<p><iframe id="J5e50" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/J5e50/5/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Another significant source of algae-feeding nutrients is agriculture, particularly cattle ranching and the sugarcane industry. Nutrient runoff from cattle ranches and dairy farms north of Lake Okeechobee end up in the lake. South of the lake, much of the <a href="https://doi.org/10.4000/miranda.2881">northern third of the Everglades</a> was converted to sugarcane farms, and those fields back-pumped runoff into the lake for decades until the state started cracking down in the 1980s. Their legacy nutrients are still in the lake. </p>
<p>The nutrient-rich water in the lake then pours down the Caloosahatchee River and into the Gulf of Mexico near Fort Myers, south of Tampa. That’s likely feeding the current red tide off the mouth of the Caloosahatchee River.</p>
<p>When water from the Everglades region’s agriculture is pumped south instead, huge blooms tend to appear in Florida Bay at the southern tip of the state. Some scientists believe it <a href="http://doi.org/10.1007/s00227-019-3538-9">may be damaging coral reefs</a> there, though there’s debate about it. During times that flow of water from the farms increased, reefs throughout the Florida Keys have been harmed. Those reefs have become overgrown with algae.</p>
<p>With the current red tide, the coastal currents have carried it north as far as Sarasota already. If they carry it farther north, it will run into the Piney Point area.</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/158568/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Larry Brand has received funding from the National Science Foundation, National Institutes of Health, Environmental Protection Agency, National Oceanic and Atmospheric Association, National Park Service, Department of Energy, Office of Naval Research, Army Corps of Engineers, Florida Department of Health, Dade County Department of Environmental Resources Management, Cove Point Foundation, and Hoover Foundation. </span></em></p>Harmful algae blooms are an increasing problem in Florida. Once nutrients are in the water to fuel them, little can be done to stop the growth, and the results can be devastating for marine life.Larry Brand, Professor of Marine Biology and Ecology, University of MiamiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1573432021-03-17T15:27:34Z2021-03-17T15:27:34ZOrigin of life: lightning strikes may have provided missing ingredient for Earth’s first organisms<figure><img src="https://images.theconversation.com/files/390104/original/file-20210317-15-aa21co.jpg?ixlib=rb-1.1.0&rect=28%2C22%2C1868%2C997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lightning on early Earth.</span> <span class="attribution"><span class="source"> Lucy Entwisle</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The origin of life on Earth is one of the most complex puzzles facing scientists. It involves not only identifying the numerous chemical reactions that must take place to create a replicating organism, but also finding realistic sources for the ingredients needed for each of the reactions.</p>
<p>One particular problem that has long faced scientists who study the origin of life is the source of the elusive element, phosphorus. Phosphorus is an important element for basic cell structures and functions. For example, it forms the backbone of the double helix structure of DNA and the related molecule RNA.</p>
<p>Though the element was widespread, almost all phosphorus on the early Earth – around 4 billion years ago – was trapped in minerals that were essentially insoluble and unreactive. This means the phosphorus, while present in principle, was not available to make the compounds needed for life. </p>
<p><a href="https://www.nature.com/articles/s41467-021-21849-2">In a new paper</a>, we show lightning strikes would have provided a widespread source of phosphorus. This means lightning strikes may have helped spark life on Earth, and may be continuing to help life start on other Earth-like planets.</p>
<p>One potential source of phosphorus on the early Earth is the unusual mineral schreibersite, which is found in <a href="https://www.liebertpub.com/doi/10.1089/ast.2005.5.515">small amounts in meteorites</a>. Experiments have shown that <a href="https://doi.org/10.1016/j.gca.2006.12.018">schreibersite can dissolve in water</a>, creating aqueous phosphorus which can react and form a variety of organic molecules important for life. Examples include <a href="https://www.nature.com/articles/srep17198">nucleotides</a>, the building blocks of DNA and RNA, and <a href="https://doi.org/10.1039/C6CP00836D">phosphocholine</a>, a precursor to the lipid molecules that make up the cell membrane.</p>
<p>But there’s another potential source for schreibersite. While studying a glass structure created by a lightning strike called a fulgurite, we found a substantial amount of the unusual phosphorus mineral inside the glass.</p>
<p>If lightning strikes created a large amount of schreibersite, and other reactive phosphorus minerals, then lightning could be an alternate source of the reactive phosphorus needed for life. </p>
<p>To determine if this was the case, we estimated the amount of phosphorus made available by lightning strikes from 4.5 billion years ago, when the Earth formed, to 3.5 billion years ago when we have the earliest fossil evidence of life.</p>
<figure class="align-center ">
<img alt="A fulgurite sample of glass on the ground." src="https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/390106/original/file-20210317-13-w7kjwx.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The fulgurite sample.</span>
<span class="attribution"><span class="source">Benjamin Hess</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Our study</h2>
<p>To do this, we needed to estimate three things: the number of fulgurites formed each year; how much phosphorus was in the rocks on early Earth; and how much of that phosphorus is turned into usable phosphorus, by the lightning strikes. </p>
<p>Fulgurites form when lightning strikes the ground, so first we needed to know how much lightning there was. To determine the amount of lightning, we looked at estimates of the amount of CO₂ in the atmosphere on early Earth and estimates of how much lightning there would be on Earth for different amounts of CO₂. The CO₂ in the atmosphere can be used to estimate global temperature, which is a key factor in controlling the frequency of thunderstorms.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/phosphorus-is-vital-for-life-on-earth-and-were-running-low-74316">Phosphorus is vital for life on Earth – and we're running low</a>
</strong>
</em>
</p>
<hr>
<p>We found that, on early Earth, there would have ranged from 100 million to 1 billion lightning strikes a year, with each strike forming one fulgurite. In total, up to 1 quintillion (one followed by 18 zeroes) fulgurites would have formed in the first billion years of Earth’s history.</p>
<p>For the second factor, we know early Earth would have likely been dominated by rocks that are similar to the basalts that make up volcanic islands like Hawaii. We used the phosphorus content in some of these <a href="https://doi.org/10.1016/S0009-2541(01)00363-1">preserved rocks</a> that are over 3.5 billion years old to determine an average phosphorus content.</p>
<p>Finally, we used our fulgurite and other published fulgurite studies to estimate of how much schreibersite, or similar forms of phosphorus, would have been made available by lightning strikes. </p>
<p>Combining all these factors we calculated lightning strikes made upwards of 10,000kg of phosphorus available for organic reactions every year.</p>
<p>Based on the best of our knowledge of early Earth, lightning probably provided as much reactive phosphorus as meteorites did around the time of the origin of life, approximately 3.5 billion years ago. Therefore, lightning strikes, along with meteorite impacts, very likely provided the phosphorus needed for the emergence of life on Earth. </p>
<h2>Life on exoplanets</h2>
<p>Our research also highlights a new source of the phosphorus needed for life to emerge on other Earth-like planets. </p>
<p>Lightning strikes are a more sustainable source of phosphorus than meteorite impacts. The abundance of large meteorites in a solar system decreases exponentially over time as the leftover material in the system collides with planets. </p>
<p>So, while meteorites provide substantial usable phosphorus for life early in a planet’s history, they decrease fairly rapidly in abundance. Lightning strikes, however, are relatively constant through time.</p>
<p>Our work helps expand the conditions in which life can form on other planets in our solar system and beyond. If any planet has an active, lightning-rich atmosphere, then the phosphorus needed for life will be available any time.</p><img src="https://counter.theconversation.com/content/157343/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Lightning strikes may have helped spark life on Earth, and may be continuing to help life start on other Earth-like planets.Benjamin Hess, PhD Candidate, Earth & Planetary Sciences, Yale UniversityJason Harvey, Associate Professor of Geochemistry, University of LeedsSandra Piazolo, Professor in Structural Geology and Tectonics, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1526522021-01-21T13:13:27Z2021-01-21T13:13:27ZInvasive tawny crazy ants have an intense craving for calcium – with implications for their spread in the US<figure><img src="https://images.theconversation.com/files/378340/original/file-20210112-23-1duz31c.png?ixlib=rb-1.1.0&rect=6%2C6%2C4019%2C3011&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Multiple queens ensure colonies have a steady output of workers.</span> <span class="attribution"><span class="source">Ryan Reihart</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>In a recent study, <a href="https://chelseprather.wordpress.com/">my colleagues</a> and <a href="https://scholar.google.com/citations?hl=en&user=6GBgzO8AAAAJ">I</a> discovered micronutrients in the ground <a href="https://www.doi.org/10.1002/ECY.3263">can control populations of invasive crazy ants</a> (<em>Nylanderia fulva</em>). </p>
<p>Tawny crazy ants – named for their fast, erratic movements – can blanket the ground by the millions. Originating in South America and now established in parts of the southern U.S., they <a href="https://www.nytimes.com/2013/12/08/magazine/crazy-ants.html">harm other insects, asphyxiate chickens and even short-circuit electronics in homes</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close up photo of a golden-colored ant against a blue background." src="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">At only 0.125 inches (3.2 mm) long, crazy ants are tiny but mighty.</span>
<span class="attribution"><span class="source">Ryan Reihart</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Crazy ants are <a href="https://doi.org/10.1146/annurev.ecolsys.33.010802.150444">liquid feeders</a> <a href="https://doi.org/10.1653/024.096.0219">that consume nectar from plants – and honeydew (or secretions) from certain insects</a>. Ants crave these sugary resources, which <a href="https://doi.org/10.1073/pnas.1115263108">boost their colony growth</a>, enabling them to outcompete native species and ultimately spread. </p>
<p>The nutritional content of nectar and honeydew vary widely, however, <a href="https://www.britishecologicalsociety.org/ant-cravings-sugar-salt-vary-across-us/">depending on the nutrients available in a particular ecosystem</a>. There are 25 chemical elements required to build life – too much or too little of one may cause disease. So far, ecologists only really know about the importance of macronutrients, like nitrogen and phosphorus, that are abundant in living tissue. My team wanted to learn more about what micronutrients might be important to crazy ants.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man kneeling over a small hole dug in the grass." src="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=801&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=801&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=801&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1007&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1007&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1007&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Installing a pitfall trap in one of the 128 fertilized study plots.</span>
<span class="attribution"><span class="source">Kiersten Angelos</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We conducted a fertilization experiment at the <a href="http://www.eih.uh.edu/">University of Houston’s Coastal Center</a> and were able to demonstrate that the abundance of tawny crazy ants decreased 24% where there was more potassium and 45% where there was more sodium and potassium. </p>
<p>What greatly surprised our team was the discovery that ants were 13% more abundant in areas where there was more calcium – even in areas that had more sodium and potassium. This finding, <a href="https://www.doi.org/10.1002/ECY.3263">published in the journal Ecology</a>, could have big implications for the continued spread of crazy ants. </p>
<h2>Why it matters</h2>
<p>Ours is the first study showing calcium is important to an invasive ant, which is somewhat surprising given ants don’t have bones. It turns out, though, calcium is important in their <a href="https://doi.org/10.1016/j.ceca.2012.11.008">egg production</a>, <a href="https://doi.org/10.1080/00218839.2015.1035074">larval development</a> and <a href="https://doi.org/10.1093/aesa/51.2.142">physiological regulation</a>. </p>
<p><a href="https://doi.org/10.1002/ece3.1737">If the spread of crazy ants continues north</a>, the calcium-rich limestone bedrock of the lower U.S. Midwest may provide ideal conditions for populations to explode. Farmlands may be at risk because calcium is found in many fertilizers. Additionally, cities often have <a href="https://doi.org/10.1007/s10980-008-9288-6">more calcium than surrounding areas</a>, thanks to heavy cement use, limestone quarrying and destruction of buildings.</p>
<p>Tawny crazy ants not only are a major threat to the biodiversity and conservation of ecosystems but also <a href="https://doi.org/10.1038/ncomms12986">cost the U.S. billions of dollars in damage annually</a>. </p>
<h2>What still isn’t known</h2>
<p>Our results add to a small but <a href="https://doi.org/10.1111/geb.13196">growing list</a> <a href="https://doi.org/10.1111/ele.13517">of other experiments</a> <a href="https://doi.org/10.1111/ele.13127">that show the importance of micronutrients</a> to insects. </p>
<p>How far will tawny crazy ants make it in the United States? Will calcium influence their spread? Could other micronutrients like magnesium or iron be important to crazy ants?</p>
<p>In a world where <a href="https://doi.org/10.1126/science.1259855">humans are changing the “ingredients” of Earth’s surface soils</a> at an alarming rate, people may be unwittingly creating more favorable habitats for some invasive species. Figuring out which elements are most important to invasive species will be key to predicting, preventing and managing their spread.</p><img src="https://counter.theconversation.com/content/152652/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ryan Reihart receives funding from the National Science Foundation (NSF) Division of Environmental Biology (DEB) grants 1457114 and 1724663 and from the University of Dayton Office for Graduate Academic Affairs through the Graduate Student Summer Fellowship Program. </span></em></p>The spread of tawny crazy ants may be driven, in part, by their need for calcium. The calcium-rich limestone bedrock of the lower U.S. Midwest may provide ideal conditions for populations to explode.Ryan Reihart, Teaching Assistant and Ph.D. Candidate of Ecology, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1488772020-11-06T14:30:47Z2020-11-06T14:30:47ZWe found a way to turn urine into solid fertiliser – it could make farming more sustainable<figure><img src="https://images.theconversation.com/files/367925/original/file-20201106-23-1uqu5iu.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3865%2C2575&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/gardener-blending-organic-fertiliser-humic-granules-1364887628">Zlikovec/Shutterstock</a></span></figcaption></figure><p>It’s likely that most of the food you’ll eat today was not farmed sustainably. </p>
<p>The global system of food production is the largest human influence on the planet’s <a href="https://science.sciencemag.org/content/347/6223/1259855.abstract">natural cycles</a> of nitrogen and phosphorus. How much crops can grow is limited by the amount of these two elements in the soil, so they’re applied as fertilisers. </p>
<p>But the majority of fertilisers are either made by converting nitrogen in the air to ammonia, which alone consumes <a href="http://www.iipinetwork.org/wp-content/Ietd/content/ammonia.html#key-data">2% of the world’s energy</a> and relies heavily on fossil fuels, or by mining finite resources, like <a href="https://www.sciencedirect.com/science/article/pii/S095937800800099X">phosphate rock</a>. </p>
<p><a href="https://doi.org/10.2166/9781780401072">A solution</a> to this problem could be much closer than people realise. Most of the nutrients we consume in food are passed in our urine, because our bodies already have enough. But instead of being recaptured, these nutrients are flushed, diluted, and sent to wastewater treatment plants where they’re scrubbed out, leaving effluents that can be safely released into the environment. </p>
<p>The most nutrient-rich part of wastewater is <a href="https://www.sciencedirect.com/science/article/pii/S0960852409002806">human urine</a>, which makes up less than 1% of the total volume but contains 80% of the nitrogen and 50% of the phosphorus. We discovered how to recycle this urine into valuable – and sustainable – farmland fertiliser.</p>
<figure class="align-center ">
<img alt="A pair of gloved hands hold a pot containing a urine sample." src="https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/367922/original/file-20201106-13-8ngh5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Urine is surprisingly rich in the nutrients needed for growing food.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/preparation-urine-samples-laboratory-hospital-study-1257550750">Tati9/Shutterstock</a></span>
</figcaption>
</figure>
<h2>How to recycle urine</h2>
<p>You can capture urine with <a href="https://www.treehugger.com/urine-separating-toilets-are-not-quite-wonderful-we-keep-saying-they-are-4858530">special toilets</a> that separate it from faeces after you flush. But because urine is mostly water, farmers would have to spread 15,000kg of it just to fertilise a hectare of land. If there was a way to remove the water and extract just the nutrients, farmers would only need to apply 400kg of it for the same effect.</p>
<p>Evaporating the water from urine is surprisingly difficult, as urine is a complex chemical solution. Almost all of the valuable nitrogen in urine is in the form of urea, a chemical that is used as the world’s <a href="http://nmsp.cals.cornell.edu/publications/factsheets/factsheet80.pdf">most commonly applied</a> nitrogen fertiliser. </p>
<p>But a fast-acting enzyme called urease is invariably present inside wastewater pipes and <a href="https://www.sciencedirect.com/science/article/pii/S0043135418304457">converts urea to ammonia</a>. When exposed to air, the ammonia quickly evaporates, taking the nitrogen from the urine with it and giving off a very pungent odour – think the stale urine smell of public toilets. </p>
<p>Fortunately, we’ve discovered that <a href="https://iwaponline.com/wst/article-abstract/74/6/1436/19385">increasing the pH of urine</a> to make it alkaline ensures the urea doesn’t break down or end up smelling really bad. Using this technique, we’ve developed a process that can reduce the volume of urine and transform it into a solid fertiliser. We call this process <a href="https://www.sciencedirect.com/science/article/pii/B978044464309400009X">alkaline urine dehydration</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A petri dish full of a dry, soil-like powder." src="https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=326&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=326&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=326&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=410&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=410&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366976/original/file-20201102-23-17rt15y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=410&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some of the fertiliser produced by drying human urine.</span>
<span class="attribution"><span class="source">Prithvi Simha</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The idea behind it is rather simple. Fresh urine is collected from urinals or <a href="https://www.sciencedirect.com/science/article/pii/S2352710219308460">specially designed toilets</a> and channelled into a dryer, where an alkalising agent, such as <a href="https://www.sciencedirect.com/science/article/pii/S0048969720328308">calcium or magnesium hydroxide</a>, raises its pH. Any water in the now alkaline urine is evaporated and only the nutrients are left behind. We can even <a href="https://www.frontiersin.org/articles/10.3389/fenvs.2020.570637/full">condense the evaporated water</a> and reuse it for flushing toilets or washing hands. </p>
<h2>A circular pee-conomy</h2>
<p>Doing this is quite easy: you just fill a urine dryer with an alkalising agent, connect it to your toilet, pee as usual and the urine is converted into dried fertiliser. A smart design could even make the dryer fit below the toilet so it doesn’t take up a lot of bathroom space. While electricity would be needed for evaporating the water, the dryer could be <a href="https://www.sciencedirect.com/science/article/pii/S0048969717302796">coupled with solar energy</a> to take its energy use off the grid.</p>
<p>We estimate that it would cost just US$5 (£4.20) to supply an average family of four with a year’s supply of alkalising agent. The output from the dryer is a solid fertiliser containing 10% nitrogen, 1% phosphorus and 4% potassium – a similar combination to <a href="https://doi.org/10.1016/j.scitotenv.2020.139313">blended mineral fertilisers</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Left: a scientist spreads fertiliser on soil. Right: the same area with short, green crops growing." src="https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=226&fit=crop&dpr=1 600w, https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=226&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=226&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=283&fit=crop&dpr=1 754w, https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=283&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/367238/original/file-20201103-15-qoz66f.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=283&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Field trials on farmland outside Paris revealed that dried urine works as well as synthetic crop fertilisers.</span>
<span class="attribution"><span class="source">Tristan Martin</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://www.baus.org.uk/museum/164/a_brief_history_of_the_flush_toilet">The first flush toilet</a>, invented by Alexander Cummings in 1775, revolutionised sanitation. Drying urine could kickstart a second revolution in how we manage wastewater. If implemented worldwide, recycled urine could replace nearly a quarter of all the synthetic nitrogen fertiliser used in agriculture. </p>
<p>But that would require <a href="https://www.sciencedirect.com/science/article/pii/B978044464309400009X">a service chain</a> capable of supplying homes with alkalising agent, collecting the dried urine and processing it into fertiliser for farmers to use. A similar service chain already exists for the recycling of plastics, metals, paper and glass – dried urine could simply be another component. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A world map highlighted to show where urine could replace more synthetic fertiliser use." src="https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=296&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=296&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=296&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=372&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=372&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366972/original/file-20201102-19-nvrah4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=372&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Countries with large populations and low rates of fertiliser use are most suitable for replacing synthetic fertilisers with urine.</span>
<span class="attribution"><span class="source">Prithvi Simha/Datawrapper and FAOSTAT</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://www.sciencedirect.com/science/article/pii/S004896971730044X">Research</a> suggests that people are <a href="https://www.sciencedirect.com/science/article/pii/S0043135418305384">open to the idea</a> of recycling urine. A survey of nearly 3,800 people across 16 countries even revealed that people would buy and eat <a href="https://data.mendeley.com/datasets/kccc8m9pn9/1">food grown using human urine</a>. With technology like this, ordinary people would have a safe and convenient way to make modern life more sustainable every time they go to the bathroom.</p><img src="https://counter.theconversation.com/content/148877/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Prithvi Simha owns shares in Sanitation360, a company which aims to commercialise urine dehydration technology.</span></em></p><p class="fine-print"><em><span>Björn Vinnerås owns shares in Sanitation360 AB. He receives funding from the Swedish Research Council Vetenskapsrådet, Formas, VINNOVA (the Swedish Innovation agency), and the EU H2020 projects Run4Life and REWAISE. </span></em></p><p class="fine-print"><em><span> Jenna Senecal is CEO of Sanitation360, a company which aims to commercialise urine dehydration technology.</span></em></p>If rolled out worldwide, our method could replace a quarter of all the synthetic nitrogen fertiliser used in agriculture.Prithvi Simha, PhD Candidate in Environmental Engineering, Swedish University of Agricultural SciencesBjörn Vinnerås, Professor of Environmental Engineering, Swedish University of Agricultural SciencesJenna Senecal, Postdoctoral Researcher in Environmental Engineering, Swedish University of Agricultural SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1177512019-12-26T21:40:07Z2019-12-26T21:40:07ZThat’s a relief! We have a way to recover phosphorus from our urine<figure><img src="https://images.theconversation.com/files/301910/original/file-20191115-47161-1cnaml8.jpg?ixlib=rb-1.1.0&rect=49%2C917%2C5472%2C2703&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Phosphorus was first discovered by boiling down thousands of litres of urine.</span> <span class="attribution"><span class="source">Shutterstock/Lesterman</span></span></figcaption></figure><p><em>To mark the <a href="https://www.iypt2019.org/">International Year of the Periodic Table of Chemical Elements</a> we’re taking a look at some of the elements used by researchers in their work.</em></p>
<p><em>Today’s focus is phosphorus, an element that is vital for life but of limited supply. But we can recover phosphorus from a source that we all give away freely, every day, our urine.</em></p>
<hr>
<p><a href="http://www.rsc.org/periodic-table/element/15/phosphorus">Phosphorus</a>, number 15 on the periodic table, can be highly toxic and flammable and has been used in warfare as an <a href="https://www.reuters.com/article/us-afghanistan-phosphorus-facts-sb/factbox-key-facts-about-white-phosphorus-munitions-idUSTRE5471T620090508">incendiary device</a>, yet it is also essential for life.</p>
<p>As the famous science writer Isaac Asimov said in his 1974 book, <a href="https://books.google.com.au/books?id=t5EoAQAAMAAJ">Asimov on Chemistry</a>:</p>
<blockquote>
<p>Life can multiply until all the phosphorus has gone and then there is an inexorable halt which nothing can prevent.</p>
</blockquote>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/titanium-is-the-perfect-metal-to-make-replacement-human-body-parts-115361">Titanium is the perfect metal to make replacement human body parts</a>
</strong>
</em>
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<p>That’s because phosphorus is essential to all living organisms. It forms the backbone of our DNA as well as the molecule adenosine triphosphate (<a href="https://www.britannica.com/science/adenosine-triphosphate">ATP</a>) that is found in cells and captures chemical energy from the food we eat.</p>
<p>We have yet to find a single living being that does not require phosphorus to survive. But we don’t have an endless supply of phosphorus, and that’s where my research comes in.</p>
<h2>Demand grows for phosphorus</h2>
<p>Demand for phosphorus and nitrogen increased dramatically in the 20th century as it was found to play a crucial role in fertiliser used for growing crops. </p>
<p>In just over 50 years (between 1961 and 2014) fertiliser production increased <a href="https://ourworldindata.org/fertilizer-and-pesticides">tenfold</a> due to the so-called <a href="https://www.encyclopedia.com/plants-and-animals/agriculture-and-horticulture/agriculture-general/green-revolution">green revolution</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305115/original/file-20191204-70116-11cp75z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Phosphorus is an important ingredient in many fertilisers used to help grow our plant based foods.</span>
<span class="attribution"><span class="source">Shutterstock/otick</span></span>
</figcaption>
</figure>
<p>This allowed for a worldwide increase in the agricultural production, particularly in the developing world, which was used to feed an ever-growing global population. </p>
<p>The high demand for nitrogen was met by ramping up a <a href="https://www.britannica.com/technology/Haber-Bosch-process">process</a> that captures nitrogen and hydrogen from fresh air and uses it to synthesise ammonia (the major nitrogen-based fertiliser). As the air in Earth’s atmosphere is made of <a href="https://climate.nasa.gov/news/2491/10-interesting-things-about-air/">78% nitrogen</a>, synthetic ammonia production was only limited by its cost. </p>
<p>But phosphorus is generally stored in solid or liquid form, and the cheapest way to cope with the high demand for phosphorus fertiliser was to extract if from phosphate rocks.</p>
<p>Phosphate rocks are a resource that is both limited and not equally distributed. The <a href="https://www.usgs.gov/centers/nmic/phosphate-rock-statistics-and-information">top five phosphate rocks holders</a> – Morocco and Western Sahara, China, Algeria, Syria, and Brazil – account for 84% of the world reserves. Australia holds just 1.6%.</p>
<p><iframe id="6Ll5J" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/6Ll5J/2/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>As phosphate rocks are a finite and non-renewable resource, the continuous extraction is causing <a href="https://www.sciencedirect.com/science/article/pii/S0959378015300765" title="A half-century of global phosphorus flows, stocks, production, consumption, recycling, and environmental impacts">uncertainties in our future supplies</a>.</p>
<h2>The wee supplies of phosphorus</h2>
<p>One solution is to look for other supplies of phosphorus, and that’s where you and I can play a role. Our urine is an excellent source of raw material for phosphorus. </p>
<p>Each one of us excretes up to <a href="https://www.sciencedirect.com/science/article/pii/S221334371830188X" title="Urine: The liquid gold of wastewater">half a kilogram</a> of phosphorus per year, just through our urine. This makes urine the <a href="https://www.sciencedirect.com/science/article/pii/S0045653511001925" title="Global potential of phosphorus recovery from human urine and feces">single largest</a> source of phosphorus from urban areas.</p>
<p>Back in the 17th century, the German chemist <a href="https://www.sciencehistory.org/distillations/hennig-brandt-and-the-discovery-of-phosphorus">Hennig Brandt</a> chose urine to isolate elemental phosphorus. In his experiment, he boiled hundreds of litres of urine down to a thick syrup until a red oil distilled up from it.</p>
<p>He collected the oil and cooled down the urine. After discarding the salts formed at the bottom of the mixture, he added back the red oil. By heating back the mixture for 16 hours, a white fume would come out, then oil, and finally <a href="https://www.sciencedirect.com/science/article/pii/S0045653511002499" title="A brief history of phosphorus: From the philosopher’s stone to nutrient recovery and reuse">phosphorus</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/b5bXTAqep6s?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>He was actually searching for the legendary <a href="https://www.sciencedirect.com/science/article/pii/S0045653511002499">Philosopher’s Stone</a> that would supposedly turn any metal into gold. He might have failed in that, but he showed how easy it was to isolate phosphorus from urine with unsophisticated tools.</p>
<h2>Reduce, reuse, recycle</h2>
<p>Today’s approaches to recycling of phosphorus from our wastes are way more practical and economical compared to Brandt’s method.</p>
<p>An increasing number of <a href="https://ostara.com/nutrient-management-solutions/">companies</a> are looking to <a href="https://www.suezwaterhandbook.com/degremont-R-technologies/sludge-treatment/recovery/recycle-phosphorus-from-effluent-to-produce-a-valuable-fertilizer-Phosphogreen">recover phosphorus</a> from waste water, including from <a href="https://www.sciencedirect.com/science/article/pii/S0043135410007025" title="Low-cost struvite production using source-separated urine in Nepal">urine</a>.</p>
<p>New <a href="http://www.vuna.ch/aurin/index_en.html">urine-derived fertilisers</a> have entered the market and the race is on to find the optimal technology to convert smelly urine into a safe, non-odorous commercial fertiliser. </p>
<p>In Australia, researchers from the University of Technology Sydney have developed a process that uses urine as a raw material to produce fertiliser and freshwater. Selected microorganisms are used to oxidise the (smelly) compounds in raw urine and convert volatile ammonia into more stable nitrates.</p>
<p>The treated urine is then filtered through a membrane, which retains the microorganisms allowing for their re-use, while allowing the soluble phosphorus and nitrogen to pass through. Treated and filtered urine is concentrated to reach nutrients concentration similar to commercial fertilisers. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/silver-makes-beautiful-bling-but-its-also-good-for-keeping-the-bacterial-bugs-away-115367">Silver makes beautiful bling but it's also good for keeping the bacterial bugs away</a>
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<p>At present, this fertiliser – named UrVal short for “You are Valuable” – is being tested at the Royal Botanical Garden in growing parsley.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Parsley grown using UrVal fertiliser at the Sydney Royal Botanical Garden.</span>
<span class="attribution"><span class="source">Dr. Ibrahim El Saliby</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Clearly, these new innovations in nutrients recovery from wastes allow us to reduce the dependence on a finite resource (phosphorus).</p>
<p>But they could also enable us to explore the possibility of one day producing food outside of planet Earth where we need fertiliser. Phosphate rocks may not be available in such places, but we’d have plenty of urine.</p><img src="https://counter.theconversation.com/content/117751/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Federico Volpin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We need phosphorus for life, as well as for fertiliser to help plants grow, but raw supplies are limited.Federico Volpin, PhD Fellow, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1286482019-12-13T12:42:37Z2019-12-13T12:42:37ZBreathable atmospheres may be more common in the universe than we first thought<figure><img src="https://images.theconversation.com/files/306102/original/file-20191210-95111-c94s3k.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4843%2C3465&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/view-earth-space-blue-planet-deep-296927021">Studio23/Shutterstock</a></span></figcaption></figure><p>The existence of habitable alien worlds has been a mainstay of popular culture for more than a century. In the 19th century, astronomers believed that Martians might be using <a href="https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Canali_and_First_Martians.html">canal-based transport links</a> to traverse the red planet. Now, despite living in an age when scientists can study planets light years from our own solar system, most new research continues to diminish the chances of finding other worlds on which humans could live. The biggest stumbling block may be oxygen – human settlers would need a high oxygen atmosphere in which to breathe.</p>
<p>So how were we so lucky to evolve on a planet with plenty of oxygen? <a href="https://www.nature.com/articles/nature13068">The history</a> of Earth’s oceans and atmosphere suggests that the rise to present-day levels of O₂ was pretty difficult. The current consensus is that Earth underwent a three-step rise in atmospheric and oceanic oxygen levels, the first being called the “Great Oxidation Event” at around 2.4 billion years ago. After that came the “Neoproterozoic Oxygenation Event” around 800 million years ago, and then finally the “Paleozoic Oxygenation Event” about 400 million years ago, when oxygen levels on Earth reached their modern peak of 21%.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-oldest-evidence-of-movement-could-change-what-we-know-about-life-on-earth-111759">How the oldest evidence of movement could change what we know about life on Earth</a>
</strong>
</em>
</p>
<hr>
<p>What happened during these three periods to increase oxygen levels is a matter for debate. One idea is that new organisms “bioengineered” the planet, restructuring the atmosphere and oceans through either their metabolisms or their lifestyles. For example, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5024600/">rise of land plants</a> roughly 400 million years ago could have increased oxygen in the atmosphere through land-based photosynthesis, taking over from photosynthetic bacteria in the ocean which have been the main oxygen producers for most of Earth’s history. Alternatively, <a href="https://www.nature.com/articles/s41467-019-10286-x">plate tectonic changes</a> or <a href="https://www.sciencedirect.com/science/article/pii/S0024493715004697">gigantic volcanic eruptions</a> have also been linked to the Earth’s oxygenation events.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=561&fit=crop&dpr=1 754w, https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=561&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/306096/original/file-20191210-95130-1y45ozq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=561&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">These stromatolites are the earliest fossil evidence of photosynthetic life. Shark Bay, Australia.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Stromatolite#/media/File:Stromatolites_in_Sharkbay.jpg">Paul Harrison/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This event-based history of how oxygen came to be so plentiful on Earth implies that we’re very fortunate to be living on a high-oxygen world. If one volcanic eruption hadn’t happened, or a certain type of organism hadn’t evolved, then oxygen might have stalled at low levels. But <a href="https://science.sciencemag.org/lookup/doi/10.1126/science.aax6459">our latest research</a> suggests that this isn’t the case. We created a computer model of the Earth’s carbon, oxygen and phosphorus cycles and found that the oxygen transitions can be explained by the inherent dynamics of our planet and likely didn’t require any miraculous events.</p>
<h2>Phosphorus – the missing link</h2>
<p>One thing we think is missing from theories about Earth’s oxygenation is phosphorus. This nutrient is very important for photosynthetic bacteria and algae in the ocean. How much marine phosphorous there is will ultimately control how much oxygen is produced on Earth. This is still true today – and has been so since the evolution of photosynthetic microbes some three billion years ago. </p>
<p>Photosynthesis in the ocean depends on phosphorus, but high phosphate levels also drive consumption of oxygen in the deep ocean through a process called eutrophication. When photosynthetic microbes die, they decompose, which consumes oxygen from the water. As oxygen levels fall, sediments tend to release even more phosphorus. This feedback loop rapidly removes oxygen. This meant that oxygen levels in the oceans were able to change rapidly, but they were buffered over long timescales by another process involving the Earth’s mantle.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/306097/original/file-20191210-95153-oclvff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Eutrophication can lead to an algal bloom. As microbes die and decompose, oxygen is stripped from the water.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dirty-green-toxic-water-contaminated-algae-294264227">Pumidol/Shutterstock</a></span>
</figcaption>
</figure>
<p>Throughout Earth’s history, volcanic activity has released gases that react with and remove oxygen from the atmosphere. These gas fluxes have subsided over time due to Earth’s mantle cooling, and our computer model suggests this slow reduction along with the initial evolution of photosynthetic life was all that was necessary to produce a series of step-change increases in oxygen levels.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-snowball-earth-volcanoes-altered-oceans-to-help-kickstart-animal-life-53280">How 'Snowball Earth' volcanoes altered oceans to help kickstart animal life</a>
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<p>These stepped increases bear a clear resemblance to the three-step rise in oxygen that has occurred throughout Earth’s history. The model also supports our current <a href="https://science.sciencemag.org/content/297/5584/1137">understanding of ocean oxygenation</a>, which appears to have involved numerous cycles of oxygenation and deoxygenation before the oceans became resiliently oxygenated as they are today.</p>
<p>What is really exciting about all of this is that the oxygenation pattern can be created without the need for difficult and complex evolutionary leaps forward, or circumstantial catastrophic volcanic or tectonic events. So it appears that Earth’s oxygenation may have been inescapable once photosynthesis had evolved – and the chances of high oxygen worlds existing elsewhere could be much higher.</p><img src="https://counter.theconversation.com/content/128648/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benjamin J. W. Mills receives funding from the UK Natural Environment Research Council</span></em></p><p class="fine-print"><em><span>Lewis Alcott does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research suggests that Earth’s oxygenation didn’t require difficult and complex evolutionary leaps forward.Lewis Alcott, PhD Researcher in Earth Science, University of LeedsBenjamin J. W. Mills, Assocate Professor of Biogeochemical Modelling, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1203902019-07-22T20:41:41Z2019-07-22T20:41:41ZScientists work to solve phosphate shortage – the dwindling resource required to grow food<figure><img src="https://images.theconversation.com/files/284227/original/file-20190716-173355-61xwpz.jpg?ixlib=rb-1.1.0&rect=50%2C8%2C5615%2C3724&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An open pit phosphate mine. An upcoming shortage of the mineral will threaten global food security.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>By 2030, the world’s population is <a href="https://population.un.org/wpp/Publications/Files/WPP2019_10KeyFindings.pdf">projected to be about 8.5 billion people</a>. Global food security is a major concern for governments - zero hunger is the second most important of the <a href="https://sustainabledevelopment.un.org/?menu=1300">United Nations Sustainable Development Goals</a>.</p>
<p>However, there is a severe conflict between sustainable food production and the use of nonrenewable resources in agricultural systems, particularly phosphate. Phosphorus is a major mineral nutrient required by crop plants for optimal growth and productivity. Phosphate is the only form of phosphorus that plants can absorb — it is often applied to crops as phosphate fertilizer. </p>
<p><a href="https://extension.umn.edu/phosphorus-and-potassium/understanding-phosphorus-fertilizers#process-619211">Phosphate is obtained through rock mining</a>. Seventy per cent of the <a href="https://doi.org/10.1016/j.resconrec.2014.10.011">world’s phosphate reserves</a> are located in North Africa. China, Russia, South Africa and the United States all have limited quantities of the mineral rock. </p>
<h2>Finite resources</h2>
<p>Scientists have reported that <a href="https://doi.org/10.1016/j.gloenvcha.2008.10.009">global phosphate production would peak</a> around 2030, at the same time the global population will reach 8.5 billion people. Several reports have also warned that the global reserve would be depleted within the next 50 to 100 years. Current agricultural practice involves the use of a high amount of phosphate fertilizer in order to achieve optimal plant yield.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284414/original/file-20190717-173376-1ds6swy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A phosphate shortage will threaten global food production: phosphate fertilizers are used extensively to produce optimal plant yield.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>This is because of the chemical properties of phosphate, which <a href="https://dx.doi.org/10.1104%2Fpp.111.175232">interacts with soil particles</a> in a way that makes it difficult for the plant to acquire, leaving a large portion of the element in the soil surface.</p>
<p>Because plants can only uptake small amounts of phosphate, a large majority of fertilizer ends up in unwanted places, like <a href="https://doi.org/10.1002/14356007.n10_n05">bodies of water</a>, making these practices ecologically and financially unsustainable. It is only reasonable to fathom that as phosphate becomes more expensive and may eventually run out, it not only poses a food security threat, but may also pose political crisis between phosphate rich countries and importing countries.</p>
<p>Many researchers across the world are committed to this effort including the <a href="http://www.gifs.ca/">Global Institute for Food Security (GIFS)</a> at the University of Saskatchewan. My doctoral research at GIFS investigates the role of mobile molecules in the integration of root and shoot growth under mineral deficiency conditions. The GIFS research team explores how molecules produced at one part of the plant — for example, the shoot — modulates the plants response to mineral stress at another part, like the root.</p>
<h2>Understanding phosphate absorption</h2>
<p>A stitch in time saves nine, and it is with this in mind that researchers across multiple disciplines are looking for ways to optimize phosphate use in crop plants. Soil scientists seek ways to improve soil phosphate management, while plant biologists have intensified their efforts in understanding how plant can adapt to limited phosphorus. </p>
<p>Indeed, considerable achievements have been made in understanding plants’ adaptive response to low phosphate in soil. For example, when plants are starved of phosphate, they stop the growth of their primary root and grow more secondary roots and root hairs in order to increase their ability to absorb phosphate in soil with lower levels of the mineral. This strategy that is referred to as <a href="https://doi.org/10.1104/pp.126.2.875">changes in root system architecture</a>.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=824&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=824&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=824&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1035&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1035&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284430/original/file-20190717-173329-al1bbs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1035&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Plants require phosphate to grow. The rice plant on the left is experiencing phosphate deprivation.</span>
<span class="attribution"><a class="source" href="http://www.knowledgebank.irri.org/training/fact-sheets/nutrient-management/deficiencies-and-toxicities-fact-sheet/item/phosphorous-deficiency">Rice Knowledge Bank</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Another strategy is that during low phosphate conditions, plants are able to <a href="https://doi.org/10.1105/tpc.105.038943">remobilize stored phosphate</a> to other parts of the plant in order to maintain growth and development. During this period too, plants change their gene expression pattern in order to adapt. They increase the expression of genes that are involved in phosphate uptake from the soil; in other words, more effort is committed to looking for and acquiring phosphate. </p>
<p>Interestingly, <a href="https://dx.doi.org/10.12688%2Ff1000research.15274.1">advancements in genomics</a> and biochemistry have helped us to uncover some of the genes and proteins that control these processes. However, some regulatory genes that control plant response to low phosphate are still unknown, making it difficult to breed crops that are well adapted to low amounts of phosphate. </p>
<h2>Protein regulation</h2>
<p>This month, a major discovery was <a href="https://doi.org/10.1104/pp.18.00594">reported</a> in the journal <em>Plant Physiology</em>. An international team of scientists discovered a protein in plants that is able to sense phosphorus levels in the soil and then tells the plant to adjust growth and flowering. The protein, called SPX4, regulates the genes that control phosphorus uptake, plant growth and flowering time. It tells the plant when it has acquired enough phosphorus and coordinates with the roots to stop uptake. </p>
<p>This discovery about how a protein integrates nutrient status with development will help us to understand how plants can perform well even with limited phosphorus application. </p>
<p>Another research published in the journal <em>Cell</em> <a href="https://doi.org/10.1016/j.cell.2019.06.021">identified a gene that regulates root system architecture</a>. Researchers showed that this gene modulates a plant hormone, ultimately regulating the depth of the root system. Although this research does not directly involve phosphate, a better understanding of root development will also help in the quest for developing crop varieties that have better adaptation to low phosphate.</p>
<p>Considering the problem at hand and the advancements in technology, this is an exciting time to study phosphate signalling in plants and develop crops that can better adapt to low phosphate. This will ultimately help us to produce enough food for the growing population without having an adverse effect on the environment. Government and funding agencies should support more fundamental and applied research that seek to understand how plants behave under low phosphate conditions.</p><img src="https://counter.theconversation.com/content/120390/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Toluwase Olukayode studies at the Global Institute for Food Security, University of Saskatchewan.</span></em></p>Global phosphate production is set to peak in 2030, around the same time the world’s population will reach nine billion. As a finite resource, a phosphate shortage will effect global food production.Toluwase Olukayode, PhD student, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1088072019-05-07T11:20:36Z2019-05-07T11:20:36ZThe deadly, life-giving and transient elements that make up group 15 of the periodic table<figure><img src="https://images.theconversation.com/files/253989/original/file-20190115-152977-vkt7qa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The red tip on these matches contains phosphorus, which ignites when in contact with oxygen.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-red-wooden-matches-standing-burning-288725405?src=eYSqUzfy1HG_Jkkm4ApeAg-1-14">Andrew Rafalsky/Shutterstock.com</a></span></figcaption></figure><p>When you see the periodic table, what comes to mind? The pieces on a scrabble board? Maybe you think about your high school chemistry class. Maybe you think of the colorful table plastered on the wall of a lecture hall in college. Maybe you remember your favorite teacher setting something on fire in the front of the classroom. I am <a href="https://blog.richmond.edu/pollocklab/">an assistant professor of chemistry at University of Richmond</a> and when I hear the phrase “the periodic table,” I think about life. </p>
<p>I think about how the molecules and chemicals that surround us and dictate our everyday activities are made up of the elements on that table – they sustain our life, they bring beauty to the world and they are vital in medicine.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252876/original/file-20190108-32136-l3sinu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here is the periodic table with all the elements blocked excepted for the ones in group 15.</span>
<span class="attribution"><span class="source">Julie Pollock</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Each column of the periodic table is called a group. Every member of the group has a similar arrangement of electrons which can result in similar chemical properties. The group 15 elements – nitrogen, phosphorus, arsenic, antimony, bismuth and moscovium – are interesting to me because of their pivotal role in life, as well as in <a href="https://blog.richmond.edu/pollocklab/">my research lab</a>. One element we study is phosphorus because of its integral role in the fate of cells. </p>
<p>But before we get into those details, let’s take a brief look at each of the group 15 elements. They are a unique set in their history, uses and properties. </p>
<h2>Group 15 – giving life and causing death</h2>
<p>Nitrogen (N) in its atmospheric form (N₂) makes up approximately 78% of the air we breathe. When bacteria living within plant roots convert it into a usable form through a process called nitrogen fixation, this elemental form of nitrogen gets incorporated into many compounds that are <a href="https://www.wiley.com/en-us/Essential+Biochemistry%2C+3rd+Edition-p-9781118441688">necessary for life – proteins and DNA, for example</a>. At the bottom of the column is Moscovium (Mc), which is interesting because it doesn’t really exist in nature. It’s a radioactive element that can only be generated in a laboratory and <a href="https://doi.org/10.1038/s41557-018-0185-6">survives for less than a second</a>.</p>
<p>Arsenic (As) may be familiar to you because of its association with poisonings. In 1494, Pico della Mirandola, an Italian humanist philosopher during the Renaissance, was poisoned by arsenic, although the details surrounding his <a href="https://doi.org/10.1016/j.jflm.2018.03.016">early death are still debated</a>. For a long time it was believed that Napoleon Bonaparte died of arsenic exposure in 1821, but after <a href="https://doi.org/10.1373/clinchem.2008.117358">extensive comparisons of preserved hair samples</a> from different stages of his life, researchers concluded the increased levels of arsenic were most likely due to preservation techniques of the time. More recently, the World Health Organization estimated arsenic-contaminated drinking water in Bangladesh <a href="https://www.who.int/ipcs/assessment/public_health/arsenic/en/">resulted in over 9,000 deaths in 2001</a>. How arsenic poisons and kills isn’t completely understood, but there is no doubt that the element causes destruction of vital organs in the human body.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/271601/original/file-20190429-194612-1scvjok.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A woman from Sonargaon, Bangladesh, shows palms affected by years of drinking arsenic-laced water.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/a8a68bf484aa458c94cf5ad9bc639ac6/a8a68bf484aa458c94cf5ad9bc639ac6/3/1">AP Photo/ A.M. Ahad</a></span>
</figcaption>
</figure>
<p>When the element antimony (Sb) is combined with three oxygen atoms to form antimony trioxide, it is used extensively as a flame retardant for furniture, carpets, drapes, rubber, plastics and adhesives. Quantities of this molecule in these household products tend to be very small, <a href="http://doi.org/10.17226/9841">and these levels of antimony are regarded as safe</a>. </p>
<p>Bismuth (Bi) is a metal found in the same row of the periodic table as a number of toxic metals; however, compounds containing bismuth are harmless. Bismuth compounds can be found in cosmetics due to their distinctive and desirable silvery shimmer. Even if you haven’t used bismuth-containing personal care products, you have probably encountered it in the well-known antacid Peptobismol®, which is <a href="https://doi.org/10.1038/nchem.609">used to treat upset stomachs</a>, or on the Fourth of July when you are watching fireworks. It is a bismuth compound that causes the crackling sounds of the <a href="https://www.youtube.com/watch?reload=9&v=ix8uHBtxxcE">dragon egg fireworks</a>.</p>
<p>Last, but not least, of the group 15 elements is phosphorus (P). It was discovered in 1669 by the alchemist Hennig Brandt and named from the Greek word “phosphoros,” meaning <a href="https://doi.org/10.1007/s11837-007-0071-y">bringer of light</a>. That’s because when the elemental form interacts with atmospheric oxygen it produces a brilliant light. Chemists figured out how to harness the power of this reaction for the development of matches. The red tip on a match still contains a form of phosphorus today.</p>
<h2>Phosphates – regulating cancer cell fate</h2>
<p>In addition to sparks generated by the element, phosphorus is found in a compound known as a phosphate: phosphorus linked to four oxygen atoms. In cells, when a phosphate molecule is attached to a protein, it can turn on, or activate, the protein so that it can perform its function in the cell – like stimulating growth. </p>
<p>When the phosphate is no longer attached to the protein, the cells stop growing. You can think of it almost like the matches described above – when the phosphate is there, the match can ignite and business can proceed. When the phosphate is removed, the match is just a stick and no light is provided; not as much work can happen in the dark. </p>
<p>In cancerous cells, the <a href="https://doi.org/10.1046/j.0014-2956.2001.02473.x">phosphate status is out of control</a>. Imagine a lot of lit matches and a very bright room that can result in a flurry of activity. This activity can have severe consequences for cells. For example, unregulated growth and migration can lead to cancer. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=303&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=303&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=303&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=380&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=380&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252877/original/file-20190108-32154-1cpc0s5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=380&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Phosphorylation in cancer cells: When a protein is phosphorylated, it is like a lit match in a room that leads to cancer cell growth. If the phosphate is removed, the match is extinguished and the cells don’t grow as much.</span>
</figcaption>
</figure>
<p>In <a href="https://blog.richmond.edu/pollocklab/">my laboratory</a> at the University of Richmond, we are interested in understanding these phosphates and one protein in particular that interacts with them. This protein, called MEMO1, is found in high quantities in breast cancer patients and helps the phosphates to always stay attached to proteins. We are trying to understand <a href="https://doi.org/10.1021/acs.biochem.8b00582">how MEMO1 interacts with these phosphates</a> and are developing strategies to disrupt those interactions. </p>
<p>We hope that our work reveals a way to help remove the phosphates to stop the unchecked growth of cells – in other words, to blow out the matches.</p>
<p>So next time you hear the words “periodic table,” please think of life. Think of the molecules that you encounter every moment of every day, think of the medicine that keeps you healthy and think of those of us who are working to understand how to keep you that way.</p><img src="https://counter.theconversation.com/content/108807/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julie Pollock receives research funding from the University of Richmond, the Mary Louise Andrews Award for Cancer Research from the Virginia Academy of Sciences, the Jeffress Memorial Trust and the Beckman Foundation. </span></em></p>The elements that make up each column of the periodic table share a set of common traits. Here, a chemist describes group 15 and the crucial role phosphorus, in particular, plays in cancer.Julie Pollock, Assistant Professor of Chemistry, University of RichmondLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1130042019-04-29T12:33:00Z2019-04-29T12:33:00ZCan we turn sewage ‘sludge’ into something valuable?<figure><img src="https://images.theconversation.com/files/271487/original/file-20190429-194603-1liaujq.jpg?ixlib=rb-1.1.0&rect=10%2C10%2C3413%2C1909&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">pxl.store / shutterstock</span></span></figcaption></figure><p>Over the past few years I have become an academic expert in “sewage sludge” – the residual, semi-solid mix of excrement packed with microorganisms that is left behind within wastewater treatment plants. Every year the UK alone produces approximately <a href="https://ec.europa.eu/eurostat/tgm/table.do?tab=table&init=1&language=en&pcode=ten00030&plugin=1">1.4m tonnes</a> of the stuff. About 80% of it is spread on fields as manure, but this still leaves us with a headache – what do we do with the rest?</p>
<p>Despite widespread recognition that a proper management plan is needed, there is one major hurdle that still needs to be overcome. Sludge is near-worthless, in terms of monetary value, and sewage companies sometimes struggle even to give it away.</p>
<p>A big part of the problem is that sewage sludge from different treatment plants can have wildly different nutrient values. Not having a product with consistent characteristics significantly undermines its value, especially for agriculture, as farmers could never be sure what it is they’re actually buying.</p>
<p>Another problem is that when stacked up against the competition, it’s actually quite poor as fertiliser. Both food waste and manure from farm animals serve the purpose much better and contain fewer pollutants that can find their way into the food chain.</p>
<p>So, what should we do with the sludge? After all, we have to do something.</p>
<p>In many cases across Europe, the water utility companies simply pay for final disposal or give it away free to farmers – a cost which is no doubt passed on to the farmers’ customers. Even in cases where the utilities manage to actually sell the treated sewage sludge, they do so at a rock bottom price of between £1 and £2 per tonne. That’s a very poor return when you consider the cost of processing a tonne of dry sludge can be £200 or more. </p>
<h2>Let it burn!</h2>
<p>What about just burning it then? It’s not very environmentally friendly, sure, but could it be a solution? The burning of feedstock such as sewage sludge results in the production of energy which is measured in calories. The more calories, the more energy that is produced.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262421/original/file-20190306-100790-1uldt0f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sludge may have some use after all.</span>
<span class="attribution"><span class="source">Noska Photo / shutterstock</span></span>
</figcaption>
</figure>
<p>Well, even “dewatered” sludge contains approximately 75% water, which means energy is required to evaporate it. And even once it’s dried out, 1 kg of dried sludge contains only 3,300 kilocalories (kcal) of energy – far less than the 4,500 kcal found in 1 kg of food waste, or even the 8,300 kcal found in <a href="http://www.sludgefacts.org/Ref87_2.pdf">1 kg of car tyres</a>. Consequently, incineration is not an attractive option for sewage sludge.</p>
<p>Luckily though, when we look at sludge as the sum of its parts, the picture becomes slightly more optimistic.</p>
<p>Around 2 to 4% of sludge contains phosphorus, from which <a href="https://www.ncbi.nlm.nih.gov/pubmed/28324850">struvite</a> – the substance kidney stones are made out of – can be recovered and sold for as much as £300 per tonne for use as fertiliser. <a href="https://www.omicsonline.org/recovery-of-calcium-carbonate-from-wastewater-treatment-sludge-using-a-flotation-technique-2157-7048.1000130.php?aid=6216">Calcium carbonate</a> too is found in significant quantities.</p>
<p>The <a href="https://link.springer.com/article/10.1007/s10163-001-0054-y">cellulose</a> contained in flushed toilet paper is also recoverable for those with the will to recover it, as is the organic content of sewage which can be recovered as <a href="https://www.sciencedirect.com/science/article/abs/pii/S0958166999800457">bioplastic</a>, a valuable alternative to conventional, petroleum-derived plastics. Both are expensive to extract, however.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/268111/original/file-20190408-2924-2mxnre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The cellulose in toilet paper can be recovered.</span>
<span class="attribution"><span class="source">New Africa / shutterstock</span></span>
</figcaption>
</figure>
<h2>Regulating the competition</h2>
<p>The adoption of extraction technology could also be helped along by increasingly strict limits on the use of phosphorus in fertilisers. In fact, a recent <a href="https://eur-lex.europa.eu/resource.html?uri=cellar:d117e80d-ec28-11e5-8a81-01aa75ed71a1.0018.02/DOC_1&format=PDF">EU proposal to regulate fertilisers</a> included manure and food waste collected at source, but excluded compost derived from sludge. Sewage sludge contains phosphorus, mostly from detergents used for washing clothes and dishes. This phosphorus is much more valuable than sludge and could eventually be used in agriculture.</p>
<p>Could we therefore be about to see the birth of a booming sludge industry? Could wastewater treatment plants become producers of brown gold?</p>
<p>Maybe. Maybe not. There are currently a plethora of directives, <a href="https://www.gov.uk/government/publications/sewage-sludge-in-agriculture-code-of-practice">codes of practice</a>, quality protocols, <a href="http://www.wrap.org.uk/collections-and-reprocessing/organic-waste/composting/report/bsi-pas-100-compost-specification">publicly available specifications</a> and assurance schemes covering the different aspects of sludge, each of which adds an additional layer to an already complex legislative framework. Such complexity is a deterring factor for investors and makes attracting new players tricky.</p>
<p>However, there is enough value in sludge that, with the right will and effort, we can start to put it to really positive use.</p>
<p>While few people like to think about what happens after we pull the flush, working out what to do with the waste is of real importance. We need to work out how best to extract the value out of sludge, because at the moment it’s literally being flushed down the toilet.</p><img src="https://counter.theconversation.com/content/113004/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Evina Katsou receives funding from the Royal Academy of Engineering, the British Council, The Natural Environment Research Council, the Horizon 2020 framework. </span></em></p>Currently, all the value in sewage sludge is literally being flushed down the toilet.Evina Katsou, Senior Lecturer in Water Engineering, Brunel University LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1132642019-03-19T10:44:06Z2019-03-19T10:44:06ZWastewater is an asset – it contains nutrients, energy and precious metals, and scientists are learning how to recover them<figure><img src="https://images.theconversation.com/files/264422/original/file-20190318-28479-189zeqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Aeration tanks at the Oaks wastewater treatment plant in New Providence, Penn.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/2aA2E9C">Montgomery County Planning Commission</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Most people think as little as possible about the wastewater that is produced daily from their showers, bathtubs, sinks, dishwashers and toilets. But with the right techniques, it can become a valuable resource.</p>
<p>On average, every Americans uses <a href="http://www.waterrf.org/PublicReportLibrary/4309A.pdf">about 60 gallons of water per day</a> for purposes that include flushing toilets, showering and doing laundry. This figure can easily double if outdoor uses, such as watering lawns and filling swimming pools, are also included. </p>
<p>Most of the used water will eventually become wastewater that must be <a href="https://water.usgs.gov/edu/wuww.html">treated before it can be discharged into nature</a>. And that treatment uses a lot of energy. According to the U.S. Environmental Protection Agency, water and wastewater facilities account for <a href="https://www.epa.gov/sites/production/files/2015-08/documents/wastewater-guide.pdf">more than a third of municipal energy budgets</a>. </p>
<p>My research focuses on <a href="https://scholar.google.com/citations?user=5Zv3mM0AAAAJ&hl=en">recovering resources from wastewater</a>. This process is difficult because wastewater contains many different types of contaminants. But researchers in our fields are exploring many creative ways to make valuable products from them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264424/original/file-20190318-28496-cvbo9s.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.epa.gov/watersense/how-we-use-water">EPA</a></span>
</figcaption>
</figure>
<h2>Energy from organic materials</h2>
<p>Diehard wastewater engineers understand the value of wastewater, which they view as an asset rather than a waste. That’s why some of them call it “used water” instead, and refer to what most people call wastewater treatment plants as water resource recovery facilities. </p>
<p>In fact, wastewater can contain <a href="http://dx.doi.org/10.1021/es2014264">more than three times the amount of energy needed to treat it</a>. One simple and mature technique for recovering part of this energy is <a href="https://www.epa.gov/anaerobic-digestion/basic-information-about-anaerobic-digestion-ad">anaerobic digestion</a>, a natural process in which microorganisms feed on grease and other organic materials in wastewater and produce biogas, just as yeast can eat up barley and spit out beer. Biogas contains <a href="https://www.epa.gov/agstar/benefits-anaerobic-digestion">roughly 50 percent methane</a>, which can be used as a renewable fuel for boilers, furnaces and heating systems or to turn turbines and generate electricity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264431/original/file-20190318-28499-104k6ig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Inside these anaerobic ‘egg’ digesters at the Deer Island Treatment Plant on Boston Harbor, microbes break down sewage sludge and scum into methane gas, carbon dioxide, water and organic solids that are processed into fertilizer.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Deer_Island_Waste_Water_Treatment_Plant#/media/File:Deerislandeggs.jpg">Frank Hebbert/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>More advanced techniques, such as <a href="http://www.genifuel.com/process.html">hydrothermal processes</a>, take sewage sludge – the solids removed from wastewater during treatment – and convert it into biobased fuels that can be used to replace gasoline and diesel fuel. This process is currently at the <a href="https://www.thesourcemagazine.org/genifuel-to-pilot-biofuel-processing-technology-in-vancouver/">demonstration stage</a>. </p>
<p>In additional to sewage sludge, many researchers – including me – are very interested in microalgae. Microalgae are <a href="https://www.energy.gov/sites/prod/files/2016/06/f33/national_algal_biofuels_technology_review.pdf">promising feedstocks for biofuels</a>, and some of them can grow in wastewater. My colleagues and I have designed hydrothermal systems to <a href="http://dx.doi.org/10.1021/acs.est.8b04035">turn wastewater-grown microalgae into biofuels</a>. They are still being tested in the lab, but we hope to scale them up in the near future.</p>
<h2>Mining nutrients from wastewater</h2>
<p>Wastewater also contains nutrients like nitrogen and phosphorus, which are essential elements that plants need to grow. In current wastewater treatment processes, we use energy to <a href="https://www.barnstablecountyhealth.org/resources/publications/compendium-of-information-on-alternative-onsite-septic-system-technology/basics-of-wastewater-treatment">convert ammonia in the wastewater</a>, which comes <a href="https://pubs.acs.org/doi/abs/10.1021/es0301018">mostly from urine</a>, into nitrogen gas. However, industries then use large quantities of natural gas to convert nitrogen gas back into ammonia, predominantly for producing fertilizer, through the <a href="https://web.archive.org/web/20080424083111/http://www.fertilizer.org/ifa/statistics/indicators/ind_reserves.asp">Haber-Bosch process</a>. </p>
<p>Clearly, it would be much more efficient to directly extract the ammonia from wastewater without converting it. One way is to use urine-diverting toilets, which already are <a href="https://www.toilettech.com/udseats">commercially available</a>, to <a href="https://theconversation.com/reinventing-the-toilet-urine-diversion-where-its-needed-most-9576">separate urine from other sources of wastewater</a>. Then the collected urine could be used as fertilizer after sanitizing it to remove pathogens. </p>
<p>Sanitized urine also contains other nutrients like phosphorus and potassium. The <a href="http://richearthinstitute.org/our-work/">Rich Earth Institute</a>, a Vermont-based nonprofit supported by federal agencies and foundations, is researching ways to turn human urine into fertilizer. The institute is testing harvested urine on real crops, and has found that <a href="https://www.npr.org/2018/02/01/582338635/could-harvesting-urine-ease-demand-for-phosphorus">it works effectively</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/xAUL8ySO1l8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Using pasteurized urine as fertilizer reduces waste and resource extraction.</span></figcaption>
</figure>
<p>Alternatively, we can recover these nutrients as <a href="https://en.wikipedia.org/wiki/Struvite">struvite</a>, or magnesium ammonium phosphate, a mineral that contains magnesium, nitrogen and phosphorus. Struvite can naturally form during wastewater treatment processes, but tends to deposit in tanks and pipes and will damage the equipment if left unattended. By controlling the formation of struvite, it can be recovered in separate reactors. </p>
<p>Researchers have tested recovered struvite on crops in laboratories and achieved yields <a href="https://phosphorusplatform.eu/scope-in-print/scope-in-press/1346-scope-struvite-as-fertiliser">comparable to commercial fertilizers</a>. The technique is still maturing, but companies are developing <a href="http://www.veoliawatertech.com/news-resources/datasheets/53931.htm">commercial versions for wastewater treatment plants</a>.</p>
<h2>More possibilities</h2>
<p>Want more valuable stuff? Wastewater is <a href="https://theconversation.com/mining-for-metals-in-societys-waste-43766">literally a gold mine</a>. It contains metals <a href="http://dx.doi.org/%2010.1021/es505329q">valued up to millions of U.S. dollars per year</a>. These metals are often toxic to aquatic life, so they need to be removed. But conventional removal technologies <a href="https://doi.org/10.1016/j.arabjc.2010.07.019">require a lot of energy and produce toxic sludge</a>. </p>
<p>Researchers are developing new ways to remove and reuse these metals, including membrane systems that can <a href="https://doi.org/10.1038/nnano.2015.310">selectively remove precious metals from water</a> and biosystems that <a href="http://dx.doi.org/10.1088/1757-899X/358/1/012024">use microorganisms to recover them</a>. These techniques are at a very early stage and it is not clear yet whether they will make economic sense, but they have the potential to make wastewater more valuable.</p>
<p>In addition, wastewater is generally warmer than natural water supplies, especially in the winter, so it can serve as a heat source. This technique is <a href="https://en.wikipedia.org/wiki/Water_heat_recycling">well-established</a> and is not limited to commercial scale. You can install <a href="https://www.energy.gov/energysaver/water-heating/drain-water-heat-recovery">drain-water heat recovery systems</a> at home to lower your energy bill.</p>
<p>To me, this is just a beginning. With proper techniques, “wastewater” can offer us much more – and I very much look forward to the day when there is no “wastewater,” just “used water.”</p><img src="https://counter.theconversation.com/content/113264/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yalin Li does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The ‘used water’ that flows from our showers, dishwashers and toilets isn’t a waste to engineers – it contains valuable materials. The challenge is recovering them and turning them into products.Yalin Li, Ph.D. Candidate/Research Assistant, Colorado School of MinesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1095352019-01-09T16:07:54Z2019-01-09T16:07:54ZPhosphorus: 350 years after its discovery, this vital element is running out<figure><img src="https://images.theconversation.com/files/253010/original/file-20190109-32154-fj6vwv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Old flame. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/match-fire-macro-photo-306131402?src=oZ_qKTTK4soG0dEl-woPeA-5-53">Petro Guliaiev</a></span></figcaption></figure><p>It’s time to buy a lot of candles. And if we light them with matches, it will only be possible because of the anniversary in question. It’s happy 350th birthday to the discovery of phosphorus, an element that is essential for life as we know it. </p>
<p>The story of how the 15th element on <a href="https://theconversation.com/the-periodic-table-is-150-but-it-could-have-looked-very-different-106899">the periodic table</a> was discovered stands as one of the great accidents of human endeavour – the chemist’s equivalent, perhaps, of Columbus setting out for India only to find the Americas by mistake. In the case of phosphorus, the explorer was Hennig Brand, a 17th-century alchemist and merchant from Hamburg, Germany. </p>
<p>Brand had been trying to achieve one of the great goals of alchemy, to make the philosopher’s stone. Alchemists thought this was the elixir of life, capable of transforming lead into gold. But where to find this legendary substance? </p>
<p>Brand was convinced that the answer was human urine, for two good reasons. First, gold and urine were a similar colour. Second, urine came from the human body, which was regarded by alchemists as a work of perfection.</p>
<h2>The discovery</h2>
<p>The actual process that Brand set up in 1669 was remarkable. One would struggle to repeat it in a garden shed nowadays – unless you had neighbours who were willing to tolerate extremely bad smells. Brand concentrated large amounts of human urine and left it to ferment. He then heated the residues, performing dry distillation, as depicted below in the 1795 Joseph Wright painting, the Alchemist in Search of the Philosopher’s Stone.</p>
<p>Brand was left with a white waxy solid which glowed in the dark even in a closed bottle, and combusted spontaneously with a very bright white flame when exposed to air. Intrigued by these properties, he named it phosphorus because this meant “light bearer” in Greek. He attempted many times to use the substance to transform lead into gold, but to no avail. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=575&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=575&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=575&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=722&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=722&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253008/original/file-20190109-32127-4t7kf8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=722&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A piss before drying.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Joseph_Wright_of_Derby#/media/File:Joseph_Wright_of_Derby_The_Alchemist.jpg">Wikimedia</a></span>
</figcaption>
</figure>
<p>Presumably disappointed, Brand may well have thought he had instead found one of the other great postulations of alchemy, pure phlogiston. Alchemy had a spiritual framework rooted mainly in ancient Greek philosophy, which stipulated that all matter is formed of four elements, or qualities – air, earth, fire and water. When heat and light were generated during combustion, alchemists thought it was because of phlogiston, a fire-like element which was contained within combustible objects and released when they burned. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-periodic-table-is-150-but-it-could-have-looked-very-different-106899">The periodic table is 150 – but it could have looked very different</a>
</strong>
</em>
</p>
<hr>
<p>The theory of phlogiston was not debunked until the 1770s, when Antoine-Laurent Lavoisier <a href="https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/lavoisier.html">showed that</a> combustion is a reaction with a gas – oxygen. More than a century after that, it became possible to transmute one metal into another – but using a nuclear reactor rather than a philosopher’s stone. Economically, however, the process has never made sense as only tiny amounts of noble metals like gold can be made in this way. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=811&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=811&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=811&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1019&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1019&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253016/original/file-20190109-32133-nxz042.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1019&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Advert from 1889.</span>
<span class="attribution"><span class="source">Goodall's Illustrated Household Almanac</span></span>
</figcaption>
</figure>
<p>On the other hand, the discovery of phosphorus opened up a dazzling new chapter in what became modern chemistry. Some 50 years after Brand’s discovery, Johann Thomas Hensing, a professor of medicine at the University of Giessen in central Germany, <a href="http://annals.org/aim/article-abstract/697146/hensing-1719-account-first-chemical-examination-brain-discovery-phosphorus-therein">showed that</a> phosphorus was also present in the human brain (it would be <a href="https://books.google.co.uk/books?id=5ufh9rM5ko0C&pg=PA2&lpg=PA2&dq=1779++pyromorphite+J.G.+Gahn.&source=bl&ots=7TZEESAvxk&sig=lM_HYaTd3tQbQjOMXsHc4-r4mpY&hl=en&sa=X&ved=2ahUKEwiK-4L7guHfAhVcShUIHYenAfsQ6AEwDHoECAcQAQ#v=onepage&q=1779%20%20pyromorphite%20J.G.%20Gahn.&f=false">decades later</a> before it was shown that there were also minerals containing phosphorus). </p>
<p>Early medicines containing elemental phosphorus started being sold, perhaps on the thinking that “if it is in your brain, it must be good for you”. This turned out to be seriously flawed, however, since white phosphorus is in fact very toxic – a fatal dose is only 1mg per kilogram of body mass. Patients <a href="https://eic.rsc.org/feature/the-medicinal-history-of-phosphorus/2020257.article">ended up</a> being poisoned as a result. </p>
<h2>Bringer of life and death</h2>
<p>Nonetheless, phosphorus is biologically vital. The average human body <a href="https://sciencenotes.org/elements-in-the-human-body-and-what-they-do/">contains</a> about 0.5kg of phosphorus, most of it in the form of phosphate to make bones and teeth strong. Phosphorus also crucially holds together DNA and RNA molecules – the backbone of these long chain-like structures contains two phosphate groups per pair of nucleic bases. Without phosphorus, it is hard to imagine any kind of life at all.</p>
<p>Foods rich in phosphorus <a href="https://www.healthline.com/nutrition/foods-high-in-phosphorus">include</a> various meats, seafood, lentils, beans, nuts and seeds. At the other end of the spectrum, white phosphorus <a href="https://accesspharmacy.mhmedical.com/content.aspx?sectionid=65101623&bookid=1163">was long</a> used in rat poison. Even more extreme, chemical warfare agents Sarin and VX are phosphorus compounds. Sarin, for example, is <a href="https://web.archive.org/web/20070808094319/http://library.thinkquest.org/27393/dreamwvr/agents/sarin1.htm">21 times</a> more deadly than potassium cyanide. It’s a great example of how elements occurring in different forms can have both very different appearances and biological effects. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253021/original/file-20190109-32130-1v8y98s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">All the above nerve agents with a ‘P’ contain phosphorus.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/chemical-weapons-structures-sarin-tabun-soman-288359330?src=CjByk0QXC8htiSGelsRGlQ-1-21">fotosotof</a></span>
</figcaption>
</figure>
<p>Phosphorus has many other positive traits. Together with nitrogen, phosphates form the basis of the fertilisers used widely in agriculture. There is no substitute for phosphorus in this role; it cannot be replaced by any other element in plants. </p>
<p>This raises an important problem. Supplies of phosphate rock – the only major phosphorus ore – are limited. So much so that phosphorus has been listed among the “endangered elements” where there is a risk to future supply. The problem is that the phosphorus used as fertiliser ends up dissolved in rivers and oceans as soluble phosphate, eventually becoming sediment. Currently there is no economically viable way of recovering it, and <a href="http://www.rsc.org/images/endangered%20elements%20-%20critical%20thinking_tcm18-196054.pdf">scientists predict</a> a shortage within about 30 to 40 years. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/well-all-be-worse-off-when-the-helium-balloon-pops-14124">We'll all be worse off when the helium balloon pops</a>
</strong>
</em>
</p>
<hr>
<p>This points to the need to develop phosphorus recycling, ideally at the point before it becomes highly diluted in our water streams. So how could this be done? Humans <a href="http://www.rsc.org/images/endangered%20elements%20-%20critical%20thinking_tcm18-196054.pdf">consume</a> 3m tons more phosphorus than they need each year, which is eventually excreted as urine and faeces. Recycling phosphorus from human waste might not sound a very uplifting endeavour, but it will be a golden egg for whoever finds a way to do it. </p>
<p>This raises an interesting point. It is tempting to look with amusement at the way Brand found phosphorus in buckets of urine. It may turn out that with the hindsight of 350 years, he was actually focusing on exactly the best place after all.</p><img src="https://counter.theconversation.com/content/109535/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Petr Kilian receives funding from EPSRC. </span></em></p>Originally found in a bucket of urine by an alchemist searching for the elixir of life, the race is on to find a way to rescue Element 15 from permanent exile in our rivers and streams.Petr Kilian, Senior Lecturer, Chemistry, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/960772018-05-04T10:49:04Z2018-05-04T10:49:04ZDead zones are a global water pollution challenge – but with sustained effort they can come back to life<figure><img src="https://images.theconversation.com/files/217590/original/file-20180503-153873-uxnbif.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Blooms of algae, like this growth in 2015 in Lake St. Clair between Michigan and Ontario, promote the formation of dead zones.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/ExAjFX">NASA Earth Observatory</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Scientists have <a href="https://doi.org/10.1029/2017GL076666">identified a dead zone</a> as large as Florida in the Gulf of Oman, which connects the Arabian Sea to the Persian Gulf. Around the world there are <a href="https://earthobservatory.nasa.gov/IOTD/view.php?id=44677">more than 400</a> current dead zones in oceans and lakes, where water contains so little oxygen that aquatic life can’t survive.</p>
<p>Dead zones form when aquatic organisms consume dissolved oxygen faster than it can be supplied. This typically happens when warmer water sits on top of colder water, or freshwater sits on top of saltier water - for example, where a river meets the sea. In either case the water on top is less dense and floats. The layers don’t mix much, so very little oxygen from the atmosphere reaches the lower layers. </p>
<p>The next ingredient is organic matter in the water. It can come from untreated sewage, or from blooms of algae, along with dead plankton and fish. This material eventually sinks into the bottom layer, where bacteria decompose it, using oxygen as fuel. This process can consume most or all of the oxygen from the water.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=296&fit=crop&dpr=1 600w, https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=296&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=296&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=372&fit=crop&dpr=1 754w, https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=372&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/217595/original/file-20180503-153881-fwfoia.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=372&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A massive dead zone forms in the Gulf of Mexico every year, fed by farm runoff that washes down the Mississippi River.</span>
<span class="attribution"><a class="source" href="https://www.epa.gov/sites/production/files/2017-08/4573.jpg">EPA</a></span>
</figcaption>
</figure>
<p>Temperature is also a factor. Higher temperatures promote faster algae growth, enhance formation of layers in the water, and reduce the amount of dissolved oxygen that the water can hold. <a href="http://dx.doi.org/10.5194/bg-10-2633-2013">Climate change</a> is tending to increase temperatures and make dead zones worse.</p>
<p>But the biggest driver is nutrient pollution – excess inputs of nitrogen and phosphorus. These nutrients stimulate algae growth. They come from municipal and industrial wastewater treatment plants, and increasingly from <a href="https://theconversation.com/nutrient-pollution-voluntary-steps-are-failing-to-shrink-algae-blooms-and-dead-zones-81249">fertilizer runoff from industrial-scale agriculture</a>.</p>
<p>A recent <a href="http://dx.doi.org/10.1126/science.aam7240">global-scale analysis</a> shows that oxygen-depleted zones in the open ocean have expanded by several million square kilometers since the mid-20th century, and oxygen concentrations at hundreds of coastal sites like the <a href="http://www.jstor.org/stable/24868567?seq=1#page_scan_tab_contents">Gulf of Mexico</a> are now low enough to limit the distribution and abundance of fish. These impacts are also being felt in <a href="https://doi.org/10.1073/pnas.1505815112">estuaries</a> and the <a href="https://doi.org/10.1016/j.jembe.2009.07.027">Great Lakes</a>. </p>
<p>As <a href="https://scholar.google.com/citations?user=-K4wV5QAAAAJ&hl=en">my research</a> has shown, large-scale dead zones are resistant to change. But nutrient reductions in the <a href="https://theconversation.com/cutting-pollution-in-the-chesapeake-bay-has-helped-underwater-grasses-rebound-92716">Chesapeake Bay</a> are starting to improve conditions there. Communities around Lake Erie <a href="https://www.sciencedirect.com/science/article/pii/S0380133014000252?via%3Dihub">dramatically reduced its dead zone and toxic algae blooms</a> in the 1970s by reducing phosphorus inputs. Now, however, these issues are <a href="https://www.cbsnews.com/news/toxic-algae-leads-ohio-to-designate-western-lake-erie-as-impaired/">resurfacing there</a> – evidence that this problem is an ongoing challenge.</p><img src="https://counter.theconversation.com/content/96077/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Donald Scavia received funding from the National Science Foundation, the National Oceanic and Atmospheric Administration, the Environmental Protection Agency, the Erb Family Foundation, the Joyce Foundation, and the University of Michigan's Graham Sustainability Institute. </span></em></p>Scientists have mapped a huge dead zone in the Gulf of Oman, without enough oxygen in the water to support life. This Speed Read explains why dead zones form in waters around the world.Donald Scavia, Professor Emeritus of Environment and Sustainability, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/743162017-03-14T16:01:00Z2017-03-14T16:01:00ZPhosphorus is vital for life on Earth – and we’re running low<figure><img src="https://images.theconversation.com/files/160487/original/image-20170313-11138-fgimr5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The stuff of life.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/focus-on-phosphorus-chemical-element-mendeleev-380077645?src=0TCLmvir6Yx_ZTdiq0XkrQ-1-8">Shutterstock</a></span></figcaption></figure><p><a href="http://www.rsc.org/periodic-table/element/15/phosphorus">Phosphorus</a> is an essential element which is contained in many cellular compounds, such as DNA and the <a href="http://hyperphysics.phy-astr.gsu.edu/hbase/Biology/atp.html">energy carrier ATP</a>. All life needs phosphorus and agricultural yields are improved when phosphorus is added to growing plants and the diet of livestock. Consequently, it is used globally as a fertiliser – and plays an important role in meeting the world’s food requirements.</p>
<p>In order for us to add it, however, we first need to extract it from a concentrated form – and the supply comes almost exclusively from <a href="https://www.theatlantic.com/science/archive/2016/11/the-desert-rock-that-feeds-the-world/508853/">phosphate mines in Morocco</a> (with far smaller quantities coming from China, the US, Jordan and South Africa). Within Morocco, most of the mines are in <a href="http://www.bbc.co.uk/news/world-africa-14115273">Western Sahara</a>, a former Spanish colony which was annexed by Morocco in 1975. </p>
<p>The fact that <a href="https://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock/mcs-2016-phosp.pdf">more than 70% of the global supply</a> comes from this single location is problematic, especially as scientists are warning that we are approaching <a href="http://www.americanscientist.org/issues/pub/does-peak-phosphorus-loom">“peak phosphorous”</a>, the point at which demand begins to outstrip supply and <a href="https://theconversation.com/peak-phosphorus-will-be-a-shortage-we-cant-stomach-25065">intensive agriculture</a> cannot continue to <a href="https://theconversation.com/how-the-great-phosphorus-shortage-could-leave-us-all-hungry-54432">provide current yields</a>. In the worst case scenario, mineable reserves could be exhausted within as <a href="http://www.sciencedirect.com/science/article/pii/S095937800800099X">little as 35 years</a>.</p>
<p>So what is going on – and how worried should be?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/160488/original/image-20170313-19256-1j44seb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Here be phosphorous.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/map-western-sahara-blue-pushpin-stuck-471656336?src=vkDq71HKb0RiDbwLKFAtnA-1-8">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Natural limits</h2>
<p>In nature, phosphorus only exists bound to oxygen, which is called phosphate. It is in this form that it is mined. Chemists can remove the oxygens bound to it to get elemental white phosphorus, which glows in the dark, but it is so unstable that it spontaneously ignites on exposure to air.</p>
<p>Phosphate easily diffuses through soil or water and can be taken up by cells. When phosphate meets free calcium or iron, they combine to give highly insoluble salts. </p>
<p>In the first half of the 19th century, Justus von Liebig popularised the <a href="https://en.wikipedia.org/wiki/Liebig's_law_of_the_minimum">law of the minimum</a> for agriculture, which states that growth is limited by the least available resource. It was soon discovered that this was often some form of phosphorus.</p>
<p>As a consequence, bones – comprised mostly of calcium and phosphate – from old battlefields were dug up to use in farming. <a href="https://www.britannica.com/topic/guano">Guano</a>, large accumulations of bird droppings, also contains high concentrations of phosphorus and was used to fertilise crops. But supplies of this were soon depleted. As demand increased, supplies had to be mined instead.</p>
<p>But this applied inorganic phosphate fertiliser is highly mobile and leaches into watercourses. In addition, phosphate rock weathers and is also ultimately washed into the ocean where it either deposits as calcium phosphate or is taken up by marine organisms who also eventually deposit on the ocean floor when they die. Consequently, terrestrial phosphorous doesn’t really disappear, but it can move beyond our reach.</p>
<h2>Natural wastage</h2>
<p>To complicate matters further, even the phosphorous we can use is largely wasted. Of the phosphorus mined as fertiliser, only <a href="http://www.mdpi.com/2073-4395/3/1/86/htm">a fifth reaches the food we eat</a>. Some leaches away and some is bound to calcium and iron in the soil. Some plant roots have the ability to extract the latter, but not in large enough quantities to retrieve all of it. </p>
<p>In addition to these inorganic forms, phosphate is also converted into cellular compounds, creating organically-bound phosphorus, such as <a href="https://www.reference.com/science/function-phospholipids-c0bbfb78de2b1593">phospholipids</a> or <a href="https://en.wikipedia.org/wiki/Phytic_acid">phytate</a>. After the death of an organism, these organic phosphorus compounds need to be returned into the useable phosphate form. How much organically-bound phosphorus is present in soils depends on the number and activity of the organisms that can do this.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/160489/original/image-20170313-11138-1ohd33y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Phosphorous boosts crop yields.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/corn-field-140658412?src=pm2Y_QViULXrR6JnuICWoQ-1-3">Shutterstock</a></span>
</figcaption>
</figure>
<p>Agricultural soils are usually rich in inorganic phosphorous while in undisturbed ecosystems, such as forests and long-term pastures, organically-bound phosphorus dominates. But agricultural land is often depleted of phosphorus during harvest and land management practises such as ploughing, hence the addition of phosphate-containing fertilisers. </p>
<p>Spreading manure and avoiding tillage are ways of increasing microbial abundance in the soil – and so keeping more phosphorus in an organically-bound form. </p>
<p>The risks of peak phosphorous can be countered with some simple solutions. Eating less meat is a start as huge amounts are used to rear <a href="http://www.npr.org/sections/thesalt/2013/02/14/172009950/should-you-be-worried-about-your-meats-phosphorus-footprint">livestock for meat</a>. The chances are that agricultural yields are limited by phosphorus availability and will be further stretched as the global population grows. </p>
<p>Humans are themselves wasteful of phosphorous, as most of what we take in goes straight out again. Fortunately, technologies have been developed to <a href="http://iahr.tandfonline.com/doi/abs/10.1080/09593332008616874">mine phosphorus from sewage</a>, but at present are too expensive to be practical. </p>
<p>Peak phosphorus does not mean that phosphorus will disappear, rather that the reserves with mineable high concentrations are depleting. Instead, we are increasing the background concentrations of phosphorus and adding it to the ocean floor. More sustainable phosphorus use requires a greater appreciation and understanding of the many organisms that make up soils – and the part they play in phosphorus distribution – or we may no longer be able to feed the world at an affordable price.</p><img src="https://counter.theconversation.com/content/74316/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vera Thoss does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It is essential to maintain global food supply, but the clock is ticking.Vera Thoss, Lecturer in Chemistry, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/544322016-02-11T12:20:53Z2016-02-11T12:20:53ZHow the great phosphorus shortage could leave us all hungry<p>You know that greenhouse gases are <a href="https://theconversation.com/explainer-how-scientists-know-climate-change-is-happening-51421">changing the climate</a>. You probably know drinking water is becoming <a href="http://www.theguardian.com/environment/2015/mar/08/how-water-shortages-lead-food-crises-conflicts">increasingly scarce</a>, and that we’re living through a <a href="https://theconversation.com/earths-sixth-mass-extinction-has-begun-new-study-confirms-43432">mass extinction</a>.</p>
<p>But when did you last worry about phosphorus? </p>
<p>It’s not as well-known as the other issues, but phosphorus depletion is no less significant. After all, we could live without cars or unusual species, but if phosphorus ran out we’d have to live without food.</p>
<p>Phosphorus is an essential nutrient for all forms of life. It is a key element in our DNA and all living organisms require daily phosphorus intake to produce energy. It cannot be replaced and there is no synthetic substitute: without phosphorus, there is no life.</p>
<p>Our dependence began in the mid-19th century, after farmers noticed spreading phosphorus-rich guano (bird excrement) on their fields led to impressive improvements in crop yields. Soon after, mines opened up in the US and China to extract phosphate ore – rocks which contain the useful mineral. This triggered the current use of mineral fertilisers and, without this industrial breakthrough, humanity could only produce <a href="http://www.sciencedirect.com/science/journal/18777058/46">half the food</a> that it does today. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=479&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=479&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=479&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=602&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=602&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111016/original/image-20160210-12137-1547sn6.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=602&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Testing crops in 1940s Tennessee.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:TVA_Results_of_Fertilizer.gif">Franklin D. Roosevelt Presidential Library and Museum</a></span>
</figcaption>
</figure>
<p><a href="http://www.earth-policy.org/data_highlights/2014/highlights43">Fertiliser use</a> has quadrupled over the past half century and will continue rising as the population expands. The growing wealth of developing countries allows people to afford more meat which has a “<a href="http://iopscience.iop.org/1748-9326/7/4/044043/media/erl437796suppdata.pdf">phosphorus footprint</a>” 50 times higher than most vegetables. This, together with the increasing usage of biofuels, is estimated <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3876211/">to double</a> the demand for phosphorus fertilisers by 2050.</p>
<p>Today phosphorus is also used in pharmaceuticals, personal care products, flame retardants, catalysts for chemical industries, building materials, cleaners, detergents and food preservatives.</p>
<h2>Phosphorus is not a renewable resource</h2>
<p>Reserves are limited and not equally spread over the planet. The only large mines are located in Morocco, Russia, China and the US. Depending on which scientists you ask, the world’s phosphate rock reserves will last for <a href="http://www.sciencedirect.com/science/article/pii/S095937800800099X">another 35</a> to <a href="http://blogs.ei.columbia.edu/2013/04/01/phosphorus-essential-to-life-are-we-running-out/">400 years</a> – though the more optimistic assessments rely on the discovery of new deposits.</p>
<p>It’s a big concern for the EU and other countries without their own reserves, and phosphorus depletion could lead to geopolitical tensions. Back in 2008, when fertiliser prices sharply increased by 600% and directly influenced food prices, there were violent riots in 40 different developing countries.</p>
<p>Phosphorus also harms the environment. Excessive fertiliser use means it leaches from agricultural lands into rivers and eventually the sea, leading to so-called <a href="https://theconversation.com/ancient-dead-seas-offer-a-stark-warning-for-our-own-near-future-47984">dead zones</a> where most fish can’t survive. Uninhibited algae growth caused by high levels of phosphorus in water has already created more than 400 coastal death zones worldwide. Related human poisoning costs <a href="http://pubs.acs.org/doi/abs/10.1021/es801217q">US$2.2 billion</a> dollars annually in the US alone.</p>
<p>With the increasing demand for phosphorus leading to massive social and environmental issues, it’s time we looked towards more sustainable and responsible use.</p>
<h2>There is still hope</h2>
<p>In the past, the phosphorus cycle was closed: crops were eaten by humans and livestock while their faeces were used as natural fertilisers to grow crops again. </p>
<p>These days, <a href="http://www.nature.com/nature/journal/v478/n7367/full/478029a.html">the cycle is broken</a>. Each year <a href="http://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock/mcs-2016-phosp.pdf">220m tonnes</a> of phosphate rocks are mined, but only a negligible amount makes it back into the soil. Crops are transported to cities and the waste is not returned to the fields but to the sewage system, which mainly ends up in the sea. A cycle has become a <a href="http://ec.europa.eu/environment/integration/research/newsalert/pdf/IR7_en.pdf">linear process</a>.</p>
<p>We could reinvent a modern phosphorus cycle simply by dramatically reducing our consumption. After all, less than <a href="http://www.fao.org/docrep/010/a1595e/a1595e00.htm">a third</a> of the phosphorus in fertilisers is actually taken up by plants; the rest accumulates in the soil or is washed away. To take one example, in the Netherlands there is enough phosphorus in the soil today to supply the country with fertiliser for the next <a href="http://www.innovatienetwerk.org/sitemanager/downloadattachment.php?id=2JoYgP2i8J8POhh460cK1k">40 years</a>.</p>
<p>Food wastage is also directly linked to phosphorus overuse. In the most developed countries, <a href="http://ec.europa.eu/environment/natres/pdf/phosphorus/sustainable_use_phosphorus.pdf">60%</a> of discarded food is edible. We could also make agriculture smarter, optimising the amount of phosphorus used by specially selecting low-fertiliser crops or by giving chickens and pigs a <a href="http://www.popsci.com/science/article/2010-09/greener-bacon">special enzyme</a> that helps them digest phosphorus more efficiently and therefore avoid extensive use of phosphorus-heavy growth supplements.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=155&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=155&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=155&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=195&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=195&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111020/original/image-20160210-12185-1mgaqsp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=195&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Original phosphorus cycle (left); the broken cycle (centre); and an optimised cycle (right).</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It takes vast amounts of energy to transform phosphate ore into “elemental phosphorus”, the more reactive and pure form used in other, non-agricultural sectors. Inventing a quicker route from raw rocks to industrially-useful compounds is one of the big challenges facing the future generation. The EU, which only has minimal reserves, is investing in <a href="http://susphos.eu/">research</a> aimed at saving energy – and phosphorus.</p>
<p>We could also close the phosphorus cycle by recycling it. Sewage, for instance, contains phosphorus yet it is considered waste and is mainly incinerated or released into the sea. The technology to extract this phosphorus and reuse it as fertiliser <a href="http://www.thameswater.co.uk/media/press-releases/17393.htm">does exist</a>, but it’s still at an early stage of development.</p>
<p>When considering acute future challenges, people do not often think about phosphorus. However, securing enough food for the world’s population is at least as important as the development of renewable energy and the reduction of greenhouse gases. To guarantee long-term food security, changes in the way we use phosphorus today are vital.</p><img src="https://counter.theconversation.com/content/54432/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>You know that greenhouse gases are changing the climate. But when did you last worry about phosphorus?Charly Faradji, Marie Curie Research Fellow, School of Chemistry, University of BristolMarissa de Boer, Researcher VU Amsterdam, Project Manager SusPhos , Vrije Universiteit AmsterdamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/533262016-02-02T12:13:44Z2016-02-02T12:13:44ZConfessions of a chemist: I make molecules that shouldn’t exist<figure><img src="https://images.theconversation.com/files/109799/original/image-20160201-32237-1bof9wc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Shaken not stirred ...</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-324857183/stock-photo-concept-of-chemistry-bookshelf-full-of-books-in-form-of-test-tube-with-chemistry-draw-on.html?src=pd-same_artist-322807478-gmrzSV2APiEo3bGPtztxxA-4">StudioVin</a></span></figcaption></figure><p>At drinks parties and dinners, if someone asks what I do for a living, I always say: “Synthetic chemist … I make new molecules … especially those that shouldn’t exist.” People typically respond that they were not very good at chemistry at school – or they enquire about explosions and smells. And there, usually, the conversation ends.</p>
<p>I worry that chemists are missing a self-promotion trick. While physicists can argue the need to understand the fundamental nature of the universe by studying subatomic particles at the <a href="http://home.cern/topics/large-hadron-collider">Large Hadron Collider</a>, we chemists beaver away using and developing fundamental knowledge of how to connect molecules together. We routinely have to overcome basic <a href="https://www.khanacademy.org/science/chemistry/thermodynamics-chemistry">thermodynamics</a>, which would stop any of us from existing if they controlled the universe – the building blocks of life would simply end up as carbon dioxide, water and ammonia. </p>
<p>I suspect chemistry’s problem is that much of it is just too useful and everyday – though not all of it, as we shall see. Chemistry tends to have recognisable applications such as making drugs, paints, plastic, synthetic fibres and electronics. The Hadron Collider, on the other hand, benefits from looking spectacular and performing abstract feats that’s appeal lies in their distance from the world that we know. </p>
<h2>My work</h2>
<p>For the past 40 years, I have worked on the chemistry of the heavier <a href="http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_16%3A_The_Oxygen_Family/1Group_16%3A_General_Properties_and_Reactions">group 16 elements</a>, including sulphur, selenium and tellurium. These have always fascinated me – in part, because the reaction chemistry is quite unpredictable. My early work was on sulphur-nitrogen compounds. Sulphur and nitrogen are quite unusual in that they both exist in nature as their basic elements. With some ingenuity it is possible to form simple compounds containing only them – a classic case of overcoming the thermodynamics that are responsible for the elements being “stable”. </p>
<p>One example is tetrasulphur tetranitride (S<sub>4</sub>N<sub>4</sub>), an orange solid with an interesting cage structure which was first made 180 years ago. The compound is perfectly stable – at least unless there is a tiny bit of heat from friction. That makes it explode violently to give sulphur and nitrogen as thermodynamics takes over. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=629&fit=crop&dpr=1 600w, https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=629&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=629&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=791&fit=crop&dpr=1 754w, https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=791&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/109805/original/image-20160201-32222-znh2ym.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=791&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">OLED on display.</span>
<span class="attribution"><a class="source" href="https://www.google.co.uk/search?client=safari&channel=mac_bm&hl=en&site=imghp&tbm=isch&source=hp&biw=1440&bih=752&q=OLED+television&oq=OLED+television&gs_l=img.3..0j0i24l8.1086.2546.0.2950.15.12.0.0.0.0.99.539.9.9.0....0...1ac.1.64.img..6.9.536.EphRXH1UhKM#q=OLED+television&channel=mac_bm&hl=en&tbm=isch&tbs=sur:fc&imgrc=HEM0D6CLA8yKCM%3A">LG</a></span>
</figcaption>
</figure>
<p>One of the main uses of tetrasulphur tetranitride is as a precursor to creating other sulphur-nitrogen compounds. It can be used, for instance, to prepare a longer chain-like molecule known as a polymer. This is truly alchemy. Known to chemists as polythiazyl, it looks metallic and golden and conducts electricity. </p>
<p>Polythiazyl was in fact the first non-metal material to be <a href="http://pubs.acs.org/doi/abs/10.1021/cr60317a002">found to be</a> a superconductor at low temperatures. This discovery was partly responsible for the whole era of <a href="http://www.colae.eu/what-is-organic-electronics/">organic electronic materials</a>, which apart from winning a <a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2000/">Nobel Prize</a> has given us the likes of <a href="http://www.whathifi.com/news/oled-tv-everything-you-need-to-know">OLED televisions</a>, which need no back light and can therefore be thinner and lighter than other televisions. How ingenious is the synthetic chemist to take two stable highly abundant elements and prepare a simple compound that otherwise would not exist? </p>
<h2>Phosphorus and tellurium</h2>
<p>My group has also worked on phosphorus-sulphur chemistry, which is important in the additives that keep engine oil from turning into tar; and phosphorus-selenium chemistry, which is behind glass-like semiconductors – these might have applications in solar cells in the longer term. <a href="http://onlinelibrary.wiley.com/doi/10.1002/chem.201303884/abstract">Most recently</a> we have been trying to make simple compounds that bond together phosphorus and tellurium (known as P-Te bonds). This is a stupidly hard thing to do. The customary wisdom is that because tellurium is metallic, simple P-Te bonds are bound to simply break and leave you with tellurium metal. To demonstrate otherwise, it took three groups working together in Canada, Germany and the UK. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/109806/original/image-20160201-32254-mqfud4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The building blocks of life.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/wolframburner/3751529776/in/photolist-spwVNd-spEeNt-6Hvz6S-4jLz3a-tKiNaS-2vQ2RQ-2vVkpu-uzBhpK-xWzRQH-w7K35w-yeLnkp-uzBhzp-sFW7z5-spwTqC-sG7n18-Anw2Ep-5dY78J-4sAnt2-9HA7tv-bcG9pV-9HiftY-6uDAoL-6uzorT-dWUQsG-6uDAa3-vbnnqf-vbnkqU-w2JjMf-osfrbr-oaKMdN-osfrjH-yd9U6S-bmMReq-w4zCGq-bx899i-scRSQ6-w5bPcM-v8aYqh-9jB4m7-w5AbQ6-e49fLS-nwjpaf-dWUMvJ">Wolfram Burner</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>I cannot envisage any ready practical application for such compounds, but that certainly doesn’t make it pointless. Learning how to manipulate the structure to stabilise a P-Te bond gives us a fundamental understanding of the forces that hold molecules together and the reaction pathways that can be employed, which is transferable to other problems in chemistry such as making stable materials for the electronics industry. </p>
<p>Along the way we developed new routes to involve certain chemicals in the process. These may prove very valuable for others working in more applied areas (it’s hard to predict what these might be). We learned that an unlikely bond is perfectly possible and can be created in compounds that can be weighed out and put on the shelf. It was also a challenging project for the PhD student who did most of the work.</p>
<p>If you want to understand the art and science of chemistry, this sort of work sums it up – making molecules that shouldn’t exist. It may not lay claim to answering life’s big questions in the same way as physics, but we are still talking about explorations in science that often benefit us in more ways than we can predict. When it comes down to it, the two disciplines are really not so different. </p>
<p>As for my team, now that we have shown what can be done with phosphorus and tellurium, we are wondering: where next? Arsenic-tellurium compounds are even more challenging, so watch this space.</p><img src="https://counter.theconversation.com/content/53326/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Derek Woollins receives funding from the Leverhulme Foundation and EPSRC.</span></em></p>Getting tellurium and phosphorus to form a molecule is stupidly hard and not very glamorous. Here’s why it’s worth the effort.Derek Woollins, Vice Principal (Research) and Provost, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/250652014-04-01T14:50:49Z2014-04-01T14:50:49ZPeak phosphorus will be a shortage we can’t stomach<figure><img src="https://images.theconversation.com/files/45310/original/rqwv96c7-1396359221.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">px PikiWiki Israel Green spice crops</span> </figcaption></figure><figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45312/original/4vjghcw3-1396359292.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Turning off the taps would negatively impact the chances of lunch.</span>
<span class="attribution"><span class="source">USDA</span></span>
</figcaption>
</figure>
<p>Here’s the good news. We probably don’t have to worry about peak oil just yet, as it isn’t going to run out anytime soon. The bad news is, as the IPCC has <a href="http://ipcc-wg2.gov/AR5/">recently reported</a>, we can’t afford the costs of what liberating all that carbon into the Earth’s atmosphere would do to the climate. So we will have to leave it in the ground and come up with alternatives fast.</p>
<p>The really bad news is that we may not even have to worry about peak oil or dangerous climate change – instead we can fret over <a href="http://www.resilience.org/stories/2013-08-29/new-projection-of-peak-phosphorus">peak phosphorous</a>. Unlike moving from our current dependence on fossil fuels, there is no alternative to phosphorus and if it runs out our global food production system would grind to a halt.</p>
<p><a href="http://www.rsc.org/periodic-table/element/15/phosphorus">Phosphorus</a> is present in all cells in all forms of life because it makes up part of the backbone of DNA – you can’t make DNA without phosphorus. We get our phosphorus by <a href="http://www.nlm.nih.gov/medlineplus/ency/article/002424.htm">eating plants</a> that have drawn up phosphorus through their roots, or by eating animals that ate the plants (or from expensive tablets).</p>
<p>Many plants do just fine by consuming the natural levels of phosphorus in the soil, but modern intensive farming methods quickly suck up phosphorus, which needs to be continually replaced. If you keep growing high yield crops on land that is irrigated with water and doused with pesticides, then you are going to come up against <a href="http://www.esajournals.org/doi/abs/10.1890/08-0127.1">phosphorus limitation</a>. And if you don’t plug that hole with fertilisers yields will dramatically decline.</p>
<p>Did farmers have this problem in the past? Yes, but they solved it in different ways. They fertilised their fields with phosphorus and nitrogen from animal waste. Manure – from horses, cows, pigs, or chickens – has the nitrogen, phosphorus and other goodies that plants need.</p>
<p>Farmers would also change the types of crops grown on a particular field and leave it fallow for a season to recover. This system, <a href="http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=124">crop rotation</a>, has been used successfully since ancient times, and improved from two to three and four-field rotations during the middle ages. There are many good things about it, but in the quest for ever greater short term crop yields, the modern system of intensive monoculture (growing the same crop all the time) farming wins.</p>
<p>But it wins because we make up for the inefficiencies of the crop-rotation system (different crops, different planting times, unproductive fallow years) by providing all the benefits it brings to the fields in the form of added fertilisers, pesticides and irrigation. All these elements of the agricultural <a href="http://www.ifpri.org/sites/default/files/pubs/pubs/ib/ib11.pdf">Green Revolution</a> requires large amounts of energy.</p>
<p>Imagine how much energy it takes to dig up phosphorus-bearing minerals, grind, and physically and chemically process it. Then transport it many miles, load it onto a spreader and tow it behind a tractor so that it finally gets onto a field. Digging up and burning stored solar energy (in the form of fossil fuels) allows us to extract phosphorus and put that onto fields in order to increase the amount of solar energy-using organisms (plants) we can grow and then eat.</p>
<h2>The chemical crunch</h2>
<p>If, or rather when, easily accessible phosphorus runs out we will either have to eat less, or decrease the amount lost from the system by increasing the quantity of phosphorus that is recycled. <a href="http://bioscience.oxfordjournals.org/content/61/2/117.full">Recycling phosphorus</a> from human and animal waste – back to manure again – or reducing the amount washed off from farmland in runoff will also take energy, probably a lot of energy due to the need for significant new infrastructure. We have the energy sources for this now, but will we when phosphorus scarcity really starts to bite? And when will that be?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45311/original/jhv9rvw4-1396359289.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An effectively non-renewable resource: a phosphate mine in Togo.</span>
<span class="attribution"><span class="source">Alexandra Pugachevsky</span></span>
</figcaption>
</figure>
<p>Unsurprisingly it depends on who you ask. Upper estimates of mineral phosphorus resources (known concentrations in the ground) are about 300 years. Lower estimates for reserves (known concentrations in the ground that are technically and economically feasible to extract) are a few decades. The only thing certain is that limitations in phosphorus supply will increase the cost of phosphorus fertilisers and so the cost of food.</p>
<p>And here’s the double whammy: some <a href="http://www.nature.com/news/2009/091007/full/461716a.html">estimates</a> give a date of peak phosphorus around the middle of this century which is when the global population will reach its possible maximum of nine billion. This is also when Sir John Beddington, a previous UK Chief Scientific Officer <a href="http://www.bis.gov.uk/assets/goscience/docs/p/perfect-storm-paper.pdf">argues</a> that humanity will need to generate approximately 50% more power, gain access to 30% more fresh water and grow 50% more food. All while significantly reducing our total carbon emissions.</p>
<p>Just when we have the greatest number of mouths to feed in all of human history, our reserves of easy to obtain, low cost phosphorus may start to run out. The worse case scenario is that many people will starve. Avoiding that outcome will require more recycling and more efficient farming practices. Getting up and running on that will require energy. Where will that low carbon energy come from in the middle of the century? </p>
<p>Will we starve or will we cook the climate? OK, that’s a false dichotomy. We could instead look at the current situation in which one billion people go hungry while another billion overeat and consider alternative scenarios in which we all get access to healthy and nutritious food. That wouldn’t require breakthroughs in fusion power or wonder GM crops but something seemingly much more challenging: our ability to share the Earth’s resources more equitably. </p><img src="https://counter.theconversation.com/content/25065/count.gif" alt="The Conversation" width="1" height="1" />
Here’s the good news. We probably don’t have to worry about peak oil just yet, as it isn’t going to run out anytime soon. The bad news is, as the IPCC has recently reported, we can’t afford the costs of…James Dyke, Lecturer in Complex Systems Simulation, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.