Estimating bioavailable reserves and potential leaching of soil P by simple chemical tests

Summary

The amounts of P extracted with acid ammonium acetate are significantly correlated with the bioavailable P reserves of Finnish soils. Together with clay percentage the simple extraction method is fairly reliable. In routine soil testing clay% can be estimated visually. Additional improvement in accuracy is possible by extraction with a strong acid. Leaching losses of P are also significantly correlated with acetate-extractable soil P, but the concentration of dissolved phosphate at a certain soil test P value varies with other soil properties and increases with decreasing pH.