Effect of Phosphorus Additions on Grain Yield, Biomass and P and As Concentration in Different Organs of Three Rice Cultivars with Different P-efficiencies Under As-contaminated Conditions

Objective)The objective of this study was to clarify the effects of P additions and P-efficiency on grain yield, biomass and quality of rice in As-contaminated soil, and discuss agronomic measures for mitigation of As accumulation in rice. (Method)Low-P tolerant rice cultivars 99011 with high P-absorption-efficiency and 580 with high P-use-efficiency, and low-P sensitive rice cultivar 99056 were used in a pot experiment to study the effects of P additions on grain yield, biomass and P and As concentration in the straw, husk and brown rice in moderate and high As-contaminated soils.(Result)Compared to no As-contamination treatment, 50 mg·kg -1 of As increased the biomass of three supplied rice slightly, but decreased grain yield significantly. Both the biomass and the grain yield increased significantly with the increase of P supply. As at 100 mg·kg -1 decreased both the biomass and the grain yield significantly. The biomass increased obviously with increasing P supply, however, the grain yield was the highest at 30 mg·kg -1 of P level but the lowest (0) at 150 mg·kg -1 of P level. Under As-contaminated conditions, the As