玉米秸秆生物炭对水稻不同生育期吸收积累As、Cd的影响

Effects of Corn Stalk Biochar on Absorption and Accumulation of Arsenic and Cadmium in Rice at Different Growth Stages

近年来稻米As、Cd含量超标的事件屡有发生,稻米质量安全问题日益突出。通过盆栽种植水稻,向As、Cd复合污染土壤中分别添加质量分数为1.00%的玉米秸秆粉末(CS)和不同温度(300、400、500℃)下制备的玉米秸秆生物炭(CB-300、CB-400、CB-500),分析水稻分蘖期、抽穗期及成熟期各部位或器官中As、Cd含量变化,探讨不同处理对复合污染土壤水稻产量的影响。结果表明,不同时期水稻As、Cd含量分布规律为:根部>茎部>叶部>糙米;玉米秸秆粉末和玉米秸秆生物炭的添加能一定程度上阻碍土壤As、Cd向水稻迁移,与CK相比,各处理均能显著降低不同时期水稻各部位Cd的含量(P<0.05),CB-500处理在三大关键生育期处理效果最佳;玉米秸秆生物炭的施加能降低不同时期水稻各部位As的含量,但各处理未达到显著水平;水稻产量方面,与CK相比,生物炭处理和秸秆粉末处理使水稻增产6.93%~55.36%。研究结果可为生物炭对砷镉复合污染土壤的治理与水稻安全生产提供理论依据和数据支持。

The occurrence of excessive Cd and As in paddy rice occurred frequently,and the rice quality and safety problems were highlighted.In order to investigate the effect of corn straw biocarbon and corn straw powder on the migration of As and Cd in rice,the effects of1%corn stalk powder(CS)and arsenic-cadmium compound polluted soil(CB-300,CB-400,CB-500)were used to analyze the changes of As and Cd contents in different parts or organs of rice at tillering stage,heading stage and Maturity stage.The effects of adding materials on rice yield were analyzed.The results showed,the contents of As and Cd in rice at different stages were:root>stem>leaf>brown rice;The addition of corn straw powder and corn straw bio-char could prevent the migration of As and Cd into rice plants,Compared with CK,the contents of Cd in different parts of rice were significantly decreased in all treatments(P<0.05),and the treatment of CB-500was the best in the three key growth stages;The application of corn straw bio-char could decrease the content of As in different parts of rice,but the treatments did not reach the significant level.Compared with CK,application of corn stalk bio-carbon and corn straw powder could increase rice yield by6.93%~55.36%.The results can provide theoretical basis and data for biological carbon control of arsenic and cadmium polluted soil and for rice safety production.