Relationship between phosphorus intensity and capacity parameters in Finnish mineral soils: I Interpretation and application of phosphorus sorption-desorption isotherms

Authors

• Helinä Hartikainen Department of Agricultural Chemistry, University of Helsinki, 00710 Helsinki 71

DOI: https://doi.org/10.23986/afsci.72103

Abstract

The interpretation and application of two types of P isotherms were elucidated by means of sorption-desorption graphs of two surface soil samples. The isotherm expressing the retention or removal of P as a function of P application indicates the direction and extent of reactions at a given initial stage. The isotherm describing the sorption or desorption as a function of P concentration in the final solution after events illustrates the P buffering power of the soil. By using simultaneously the isotherms of both types, all information included can be integrated and the graphs can be used as a dynamic model describing P exchange.