Adsorption of Phosphate and Water‐extractable Soil Organic Material by Synthetic Aluminum Silicates and Acid Soils

Abstract

AbstractThree synthetic Al silicates with different Si/Al ratios and soil samples from a Eutrandept, a Paleudult, and a Haplaquod, were separately treated with P and hot water‐extractable soil organic materials. The Al silicate with the lowest Si/Al ratio retained the most P but the least organic materials. The Paleudult which had a lower P adsorption capacity retained more organic matter than the Eutrandept. The Haplaquod had the lowest P and organic matter retention.Pretreatment of soils with organic material had varied effects on subsequent P adsorption. Pretreatment of soils with P reduced the adsorption of organic material, but at all organic matter levels the P adsorption was constant.The findings suggested that the sites for organic matter and P adsorption may differ, but certain sites seem to adsorb both P and organic matter.