Testing soil samples at the Canadian Light Source has helped a University of Saskatchewan soil scientist understand how tripolyphosphate (TPP), a slow release form of phosphorus fertilizer, works in the soil as a plant nutrient for much longer periods than previously thought.
Jordan Hamilton says the research also has implications for ongoing efforts by U of S soil scientists to use phosphorous-rich materials to clean up contaminated petroleum sites.
Hamilton, now a post-doctoral fellow working within U of S professor Derek Peak’s Environmental Soil Chemistry group, had a chapter of his PhD thesis, “Chemical speciation and fate of tripolyphosphate after application to a calcareous soil,” published earlier this year in the online journal Geochemical Transactions.
TPP needs to break down into a simpler form of phosphate in order to be used as a nutrient by plants. In most types of soil, the belief was that TPP would break down right away, says Hamilton.
“I would definitely say the biggest surprise is how quickly the TPP adsorbed (attached itself) to mineral sources, especially in these calcium-rich soils,” he said. “For the longer term, it was surprising to see it persist.”