Evaluation of water and ammonium acetate tests as indices for available P in limed soils

Authors

• Helinä Hartikainen Department of Agricultural Chemistry, University of Helsinki, SF-00710 Helsinki

DOI: https://doi.org/10.23986/afsci.72346

Abstract

The water and acid acetate extractions as predictors of the P uptake by plants were compared in a two-year pot experiment and a simultaneous incubation test. The accuracy of these methods was dissimilarly affected by individual cultivation measures, such as the addition of nutrient salts and liming. In contrast to acetate-extractable P, the water-soluble P proved to be sensitive to the salt addition reducing the water extraction test values markedly. On the other hand, in limed soils the water-soluble P seemed to be more closely related to the P uptake by plants than the acetate-extractable P which tended to overestimate available reserves.