[Effect of Different Safety Utilization Measures on Reducing Cadmium in Rice in High Geological Background Area of...

In order to ensure the safe production of rice in the Cd-polluted farmland in southeast Chongqing， field experiments of low accumulation variety （D）， soil conditioner （T）， leaf surface barrier agent （Y）， low accumulation variety combined with soil conditioner （DT）， low accumulation variety combined with leaf surface barrier agent （DY）， and low accumulation variety combined with soil conditioner and leaf surface barrier agent （DTY） were carried out in typical acidic yellow soil in southeast Chongqing. The effects of different safe utilization techniques on Cd content in rice were compared. The results showed that all the safe utilization techniques could reduce the content of Cd in rice seeds to varying degrees， but only D， T， or Y safe utilization measures existed in the test plot. Planting rice varieties with low accumulation combined with soil conditioner or leaf barrier agent （DT， DY， and DTY） could reduce the Cd content of rice seeds below the food safety limit specified in GB 2762-2022. In the treatment groups （T， DT， and DTY） treated with calcium soil conditioner， the soil pH value was significantly increased， and the content of available Cd in the soil was decreased， which effectively inhibited the migration of Cd from soil to roots， stems， and leaves of rice. The amount of TF seed/stem and leaf in the treatment group （Y， DY， and DTY） was significantly lower than that in the CK treatment group （P <0.05）， indicating that the leaf and leaf blocking agent improved the fixation of Cd in the stem and leaf and thus reduced the transfer of Cd from the stem and leaf to the seed. The difference of rice varieties with low accumulation was mainly manifested in the difference of Cd transport from roots to stems and leaves. Compared with that in CK， all treatment groups showed different degrees of yield increase， among which the DY treatment group with low accumulation variety combined with leaf barrier agent had the highest yield. Under the premise of ensuring the safety of rice seed Cd， the integrated technology of low accumulation varieties combined with leaf surface barrier is the best combination measure to ensure the safe utilization of acidic yellow soil in the high geological background area of southeast Chongqing， taking into account the factors of rice yield， economic cost， and the acceptance of farmers.