外源硫化钠对土壤-水稻体系中镉迁移积累的影响  

Effects of exogenous sodium sulfide on cadmium migration and accumulation in soil and rice plant systems

作　　者：官迪[1] 吴家梅[1] 刘昭兵[1] 陈山[1] 纪雄辉[1] GUAN Di;WU Jiamei;LIU Zhaobing;CHEN Shan;JI Xionghui(Hunan Academy of Agriculture Sciences/Key Laboratory of Agriculture Environment in Middle Reach Plain of Yangtze River Ministry of Agriculture/Key Lab of Prevention,Control and Remediation of Soil Heavy Metal Pollution in Hunan Province,Changsha 410125,China)

机构地区：[1]湖南省农业科学院/农业部长江中游平原农业环境重点实验室/农田土壤重金属污染防控与修复湖南省重点实验室,长沙410125

出　　处：《农业环境科学学报》2021年第7期1460-1469,共10页Journal of Agro-Environment Science

基　　金：国家重点研发计划项目(2017YFD0801504);湖南省农业科技创新资金项目(2017QN33)。

摘　　要：研究外源硫化钠对土壤-水稻系统中镉(Cd)形态变化及迁移积累影响,为硫素固定土壤活性Cd、降低稻米Cd积累的应用提供依据。本实验采用室内土壤培养和盆栽种植试验方法,研究不同硫化钠用量对水稻-土壤系统中Cd的迁移积累变化的影响。结果表明:施用0.1 g·kg^(-1)硫化钠,水稻根系及稻谷生物量相比空白对照组增加59%,同时有效降低水稻器官组织中Cd的积累;0.5 g·kg^(-1)硫化钠处理下水稻根系、茎叶中Cd的积累分别下降76%、70%;稻谷中Cd的含量随着硫化钠施用量的增加呈现显著降低趋势,当施用量为0.3 g·kg^(-1)时,稻米Cd降幅最大(降低68%),继续增加硫化钠用量,稻米Cd降幅无显著差异;适量施用硫化钠能有效降低土壤中离子态Cd含量,最高降幅为55%;DTPA提取态Cd降幅约为17%。同时S2-在土壤溶液中发生氧化还原反应,形成的硫酸盐在一定程度上缓解了土壤pH的增加。研究表明增施硫化钠0.3 g·kg^(-1)能提高作物产量和降低Cd在土壤-水稻系统中的迁移效率,有效降低籽粒中Cd的积累。This study aimed to explore the effects of exogenous sodium sulfide application on the morphological change,migration,and accumulation of cadmium(Cd)in soil–rice plant systems,which could provide a practical sulfur fertilizer application strategy for the passivation of soil active Cd and decrease Cd content in grain.The study used soil culture and pot plant experimental methods to measure Cd migration changes and the accumulation in a soil–rice plant system with different application amounts of sodium sulfide.The results showed that rice yield under the 0.1 g·kg^(-1) Na2S treatment was significantly increased by 59%compared to the control.With the application of sodium sulfide,Cd accumulation in the organs and tissues of the rice plants was efficiently decreased.In the 0.5 g·kg^(-1) sodium sulfide treatment,Cd content in the roots and stems decreased by 76%and 70%,respectively,compared to the control.Among all the sodium sulfide treatments,Cd accumulation in grain was the lowest in the 0.3 g·kg^(-1) treatment,which was decreased by 68%.With further increase in the sodium sulfide dosage(greater than 0.3 g·kg^(-1)),decreased Cd content in the grain showed no significant difference.Therefore,appropriate sodium sulfide application could effectively passivate ionic Cd and DTPA-Cd content in the soil,and the passivation efficiency was 55%and 17%,respectively.It is speculated that S2-had REDOX reaction in the soil environment,and the sulfate formed alleviates the increase of soil pH to a certain extent.In brief,adding 0.3 g·kg^(-1) sodium sulfide could increase crop yield and effective in immobilizing Cd and inhibiting translocation of Cd into the grains,which is the optimum choice for soil Cd immobilization.

关 键 词：硫离子 镉 水稻 土壤 积累 迁移 

分 类 号：X132[环境科学与工程—环境科学]