Mobilization of soil phosphorus by low-molecular-weight organic acids

P mobilization from calcareous and acidic soils by citric, malic, oxalic and tartaric acids has been studied with chemical extraction and flow technique methods. Results showed that the release of soil phosphorus was significantly stimulated by organic acids. The P mobilizing ability of low-molecular-weight organic acids (LOA) followed the order: citric > oxalic > tartaric > malic acid. The phosphorus mobilized from acidic soils was higher than that from calcareous soils.