顾国平　章明奎

摘 要：为了解农田水分管理方式与秸秆还田对砷污染农田中生长农作物吸收砷的影响，在某一砷污染农田的水稻-油菜连作系统中设置稻季淹水灌溉与湿润灌溉和稻季秸秆还田与油菜季秸秆还田双因素试验，分析不同水分管理和秸秆还田对水稻和油菜各器官中砷积累的影响。结果表明，油菜籽粒中砷含量明显低于水稻谷物；稻季湿润灌溉水稻籽粒及茎叶中砷含量低于淹水灌溉，前者为后者的47.59%～48.30%和6.43%～13.36%；稻季水分管理方式对后续作物油菜籽粒砷积累影响不明显。水稻秸秆在油菜田还田处理的水稻籽粒中砷含量低于油菜秸秆在水田还田处理的水稻籽粒，但秸秆还田时间对油菜籽粒中砷含量影响不明显。分析表明，湿润灌溉土壤水溶性As（Ⅲ）和As（Ⅴ）总量及As（Ⅲ）/As（Ⅴ）的比例都显著低于淹水灌溉。研究认为，湿润灌溉和水稻秸秆油菜季还田可降低农产品中砷的积累。

关键词：水分管理；秸秆还田；农产品质量安全；砷污染

中图分类号 S511 文献标识码 A 文章编号 1007-7731（2017）12-0019-04

Abstract：In order to understand the effect of water management and straw returning on the absorption of arsenic by crops from arsenic contaminated farmland soil，a pot experiment was conducted in a rice-rape continuous cropping system to study the effects of two kinds of water managements（flooding irrigation and wet irrigation） and two ways of straw returning（rice straw returning and rape straw returning） on arsenic（As） accumulation in the different organs of two plants.The results showed that the arsenic content in rape seeds was significant lower than that in rice grain.The contents of arsenic in grains，stems and leaves of rice with wet irrigation were lower than those with flooded irrigation，the former were 47.59%～48.30% and 6.43%～13.36%，respectively，of the latter.Water management modes in rice growth season had no significant effect on the accumulation of arsenic in the following rape season.The content of arsenic in rice grain for rice straw returning to rape field was lower than that for rape straw returning to rice field. However，the effect of straw returning time on the content of arsenic in rape seeds was not obvious.Total concentrations of water soluble soil As3+ and As5+ and the As3+ / As5+ ratio for wet irrigation was significant lower than those for rice straw returning.The results suggested that both wet irrigation and rice straw returning could control the accumulation of arsenic in agricultural products.

Key words：Water management modes；Straw returning；Safety of agricultural product；Arsenic contamination

砷是环境中最常见、危害人类健康最严重的污染物之一，被美国环保局（USEPA）与世界卫生组织（WHO）认定为已知的人类致癌物质。人体吸收过量的砷或长期暴露于富砷环境中，可诱发皮肤癌及导致肾、肝、膀胱等内脏器官的癌变。环境中砷的来源主要有砷化物的开采和冶炼、含砷有色金属的开发和冶炼、砷化物的广泛应用、含砷农药的生产和使用及煤的燃烧等[1]。随着砷化学物质在工农业生产中的不断应用，土壤、大气和水体中的砷污染已成为一个全球性的严重问题，正危胁着农作物生产和人类的健康[2-4]。……