LAUSR

To better understand the Sb phytoavailability in rice, we studied Sb accumulation in rice (Zhongjiazao-17, widely cultivated in Hunan province) at different growth stages based on adding SbIII and SbV to waterlogged soils in 10, 50 and 100 mg kg-1 treatment levels. Proportional exogenous SbIII and SbV remained in the soil solution after equilibration. In SbIII treatments, the iron plaque (IP) amounts and Sb in rice roots sharply increased from tillering to jointing stages and then reduced at the following stages. However, in SbV treatments, they increased continuously from tillering to maturing stages. The accumulation trends of Sb in straws, ears and grains were consistent in SbIII and SbV treatments, rising from tillering to jointing stages followed with reducing from jointing to flowering stages slightly, and rising again significantly from flowering to maturing stages. The Tfsoil-grain values in all the Sb treatments were low (0.77 × 10-3-5.1 × 10-3), However, when Sb in waterlogged soils were higher than 50 mg kg-1, it could pose human health risk for residents.