Changes in soil P pools during legume residue decomposition

Abstract

There is a growing interest to find effective management systems to utilise the large unavailable soil P bank resulting from the excess use of P fertiliser and to overcome the associated financial and environmental problems. It has been suggested that legume residues can play a significant role in mobilising soil P forms which are unavailable to many crops. The aim of our experiment is to study the changes in soil P pools during legume residue decomposition. Legume residues with varying P concentrations were added to a sandy loam soil with low P availability and changes in various soil P pools were determined after 14 days. Residue addition increased available P. Residues with lowest C/P ratio (46.9) increased the NaHCO3 extractable inorganic P 4.82 fold compared to the control (22.9 mg /kg). Cumulative respiration over 14 days was higher in soil treated with young residues compared to control and mature residues.