摘要
当前土壤调理剂在水稻Cd污染防治方面的应用,主要集中在华东、华中、华南等工农业污染区,而在西南喀斯特高Cd地质背景区应用较少。本文在贵州罗甸喀斯特高地质背景区开展了土壤-水稻Cd对NPK复合肥、菜籽饼肥、牛粪、硅钙镁肥调理剂及组合的响应试验研究,结果显示:(1)与种植前相比,各调理剂及组合处理下土壤有效态镉(DTPA-Cd)含量平均降低了21.6%、可还原态Cd含量占比平均降低了5.84%、弱酸提取态Cd含量占比平均提高了5.53%、可氧化态和残渣态Cd含量占比基本保持不变;(2)与空白相比,除NPK复合肥+菜籽饼肥外各调理剂及组合处理下糙米Cd含量平均降低了24.7%、糙米Cd富集系数平均降低了20.0%;(3)NPK复合肥+牛粪这种传统种植(施肥)模式效果最优,土壤DTPA-Cd含量降幅最大(28.1%)、糙米Cd含量最低(0.182 mg/kg)、糙米Cd富集系数最低(0.0230),值得开展更大范围的试验示范与推广。本研究区土壤-水稻Cd对各调理剂及组合的响应明显不同于我国工农业污染区,体现了喀斯特区域特点:淹水致使土壤中占主导的可还原态Cd一定程度地被活化,弱酸提取态Cd占比相应地提高,但富碳酸钙镁的岩溶水灌溉驱动碳酸盐与Cd共沉淀的钝化机制,总体降低了土壤Cd的生物可利用性。
At present,the application of soil conditioners in the prevention and control of cadmium(Cd)pollution in rice is mainly concentrated in the industrial and agricultural pollution areas such as East China,Central China,and South China,but less in the Karst area with high geological background of Cd in southwest China.In this study,an experimental study on the response of soil-rice Cd to nitrogen,phosphorus and potassium(NPK)compound fertilizer,rapeseed cake fertilizer,cow dung,silicon calcium magnesium fertilizer conditioner and their combination was carried out in the Karst high geological background area of Luodian,Guizhou.Results showed that:(1)Compared with before planting,under each conditioner and combination treatment,the content of soil available cadmium(DTPA-Cd)decreased by an average of 21.6%,the proportion of reducible Cd decreased by 5.84%,and the proportion of weak acid-extracted Cd increased by 5.53%on average.The proportion of oxidizable and residual Cd remained basically unchanged;(2)Compared with blank value,the Cd content of brown rice was reduced by 24.7%on average,and the Cd enrichment coefficient of brown rice was reduced by 20.0%on average under each conditioner and combination treatment except NPK compound fertilizer+rapeseed cake fertilizer;(3)The traditional planting(fertilization)mode of NPK compound fertilizer+cow dung had the best effect,the soil DTPA-Cd content had the largest decrease(28.1%),the Cd content in brown rice was the lowest(0.182 mg/kg),and the Cd enrichment coefficient in brown rice was the lowest(0.0230),it was worth carrying out a wider range of experimental demonstration and promotion.The responses of soil-rice Cd to various conditioners and combinations in this study area were obviously different from those in industrial and agricultural pollution areas in China,which reflected the characteristics of Karst areas:The flooding caused the dominant reducible Cd in soil to be activated to a certain extent,and the proportion of weakly acid-extracted Cd increased accordingly.H
作者
冉刚
杨寒雯
蔚蓝
刘秀明
王世杰
RAN Gang;YANG Hanwen;WEI Lan;LIU Xiuming;WANG Shijie(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China;Puding Karst Ecosystem Observation and Research Station,Chinese Academy of Sciences,Puding Guizhou 562100,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2023年第3期330-337,共8页
Earth and Environment
基金
国家重点研发计划项目(2018YFD0800602)
贵州省高层次创新型人才培养计划“十”层次人才项目(黔科合平台人才[2016]5648)。
