砷在土壤中的形态分布与青菜的生物学效应

Distribution of As Forms in Soils and Biological Effect of As on Chinese Cabbage (Brassica chinensis L.)

研究砷在粘盘黄褐土上的形态分布特征及粘盘黄褐土、红壤 (高肥力、低肥力 )、水稻土中 AEC与土壤砷形态的关系 ,探讨砷对青菜 (矮脚黄 )的生物学效应。结果表明 ,外源砷浓度高时土壤砷形态以固定态砷为主 ,外源砷浓度低时以活性态砷为主 ,尤以交换态砷为主 ;施入紫云英土壤砷的活性增强 ;土壤 AEC与活性砷含量呈线性正相关。土壤砷浓度 <4 0 mg/kg时对青菜 (矮脚黄 )生长有刺激作用 ,土壤砷浓度 >4 0 mg/kg时青菜 (矮脚黄 )生长受抑制 ;土壤砷浓度 >4 0 mg/kg时施磷肥可加重砷对青菜 (矮脚黄 )

The distribution of As forms in yellow cinnamon soil of play pan and the relationship between As forms in soils and AEC form yellow cinnamon soil,red soil with high fertility and low paddy soil were studied,and the biological effect of As forms on Chinese cabbage was also discussed.The results showed that As forms in soils were mainly composed by fixed forms of As when As added at high rate and soil As forms were mainly composed by labile As,esp.exchangable As,when As added at low rate.The lability of soil As was improved when astragalusy (Astragalus sinicus) was added.AEC of soils was linearly positive related to labile As in soils.Soil As less than 40 mg/kg enhanced the growth of Chinese cabbage,while soil As more than 40 mg/kg inhibited the growth of Chinese cabbage.