The effect of different water managements on rice arsenic content in two arsenic-spiked soils

Growing rice on arsenic (As)-contaminated paddy fields may induce high As level grain production. In order to reduce the food contamination risk, the pot experiments containing two As-spiked aging soils and four water managements were conducted to evaluate the effects of water managements on rice As content. The results indicated that As concentration of Erlin soil solution was 10 to 20 times (210-520 µg/L) higher than that of Pinchen soil solution (5-20 µg/L) at early stage of experiment (0-60 days). Aerobic water treatment will decrease As level to 30-50% (108-220 µg/L) of original As concentration in Erlin soil solution. Statistic results indicated that water management was effective to reduce the rice grain As level in Erlin soil. However, the management impact was not obvious in Pinchen soil, which may be attributed to high clay or free Fe and Al content in the soil. This study suggested that keeping soil under aerobic condition for 3 weeks before rice heading can reduce the risk of rice grown at the As-contamination soil.