When it comes to phosphorus, we need to get smarter

International scientists have found that Australia’s pasture systems, on average, have low phosphorus-use efficiency (15-30%) while most broadacre grain operations average around 50-60% efficiency.

Researchers say that the major avenue for addressing inefficiencies and increases in phosphorus fertiliser cost could be addressed through improving fertiliser technologies; breeding plants that can more efficiently take up phosphorous from the soil or grow better in lower-phosphorus soils; and applying the right amounts of phosphorus fertilisers at the right times.

According to Dr Richard Simpson from CSIRO’s Sustainable Agriculture Flagship, with a few exceptions, improvements in using phosphorus efficiently have been stalled for years.

“Ideally we would like to be applying only one kilogram of phosphorus as fertiliser to produce one kilogram of phosphorus in food and fibre products,” Dr Simpson said.

“But for every kilogram of phosphorus that ends up in farm products, usually two to four kilograms of phosphorus has been added to the soil in fertiliser. This is because most Australian soils tend to hold on to phosphorus when they are fertilised and plants can’t access it.”

Read more at CSIRO