Effects of Liming and Straw Returning on Cadmium Content in Rice Grains in a Clean and Acidic Paddy Field
The study was conducted to investigate the effect of lime application on the cadmium(Cd)content in grains of double rice in a clean and acidic paddy field(soil pH 5.2,soil Cd content 0.2 mg/kg).Four treatments were set up to measure the cadmium contents in rice grains.The treatments were as following:(1)straw removal without liming as control,(2)straw removal with lime application,(3)straw returning every season without liming,(4)straw returning combined with liming.The results showed that lime application significantly reduced the Cd content in brown rice in the early and late rice season except that in the late rice season in 2020.Straw returning had no significant effects on the Cd content in brown rice.There were interactive effects between liming and straw returning on the Cd content in brown rice in the early rice season in 2020.Lime application reduced the Cd content in brown rice by 61.0％under straw returning and by 38.0％under straw removal in the early rice season in 2020.Lime application significantly reduced the Cd content in polished rice in both the early and late rice seasons in 2019.Straw returning significantly increased the Cd content in polished rice in the late rice season in 2020.There were interactive effects between liming and straw returning on the Cd content in polished rice in the late rice season in 2020.Lime application reduced the Cd content in polished rice by 38.1％under straw returning,while only by 4.2％under straw removal in the late rice season in 2020.Therefore,lime application can not only reduce the Cd content in rice grains,but alleviate the risk of Cd pollution caused by straw returning in the clean and acidic paddy field,thereby contributing to food safety.
NETL
NSTL
万方数据
