Transformation of phosphate in rice (Oryza sativaL.) rhizosphere and its influence on phosphorus nutrition of rice

Abstract

Abstract Rice (Oryzu sativa L.) nutrition is greatly dependent on the phosphorus (P) status in the rhizosphere. A greenhouse experiment was carried out with rice grown in four low‐pH soils (granitic lateritic red earth, a paddy soil from the red earth, a basaltic ]atosol, and a paddy soil from the latosol) to investigate the transformation of phosphate in the rice rhizosphere. Rice was grown in pots with the roots confined in rhizobags, and the rhizosphere soil and nonrhizosphere soil were analyzed for iron (Fe)‐bound P, aluminum (Al)‐bound P, and clacium (Ca)‐bound P by Chang's method. The concentration of three different forms of P decreased in the order of Fe‐P > Al‐P > Ca‐P for the granitic soils, whereas the order was Fe‐P > Ca‐P > Al‐P for the basaltic soils. The difference between the rhizosphere soil and the nonrhizosphere was statistically significant for Fe‐P and Al‐P but not for Ca‐P. The ?Pi was defined as tile difference in P of form “i”; between the rhizosphere soil and nonrhizosphere soil, ...