Cd胁迫下As污染土壤对农作物生长及农产品安全性的影响

采用盆栽实验的方法研究了在Cd胁迫下As污染物对水稻(Oryze sativa L.)、大豆(Glycine mdx L .)生长发育及重金属吸收积累的影响,As-Cd污染土壤采用不同改性剂对农产品安全性的影响研究.研究结果表明:单元素As处理与对照相比水稻株高降低了10.3锄、产量下降了9.8%,而大豆株高、产量分别增加了6 cm、36.9%,在实验设计污染物浓度范围内,As对大豆生长发育有刺激作用.As-Cd处理与对照相比水稻的株高、产量分别下降了2.3 cm、1.75%,而大豆株高、产量下降了12 cm、5.6%,As-Cd污染处理抑制了作物的生长发育;As-Cd处理比单元素As处理其水稻籽实、茎叶、根中As含量分别多4.2倍、1.14倍、1.7倍,As-Cd处理比单元素As处理大豆籽实、茎叶、根中As含量分别多4.63倍、2.82倍、1.85倍,Cd元素的存在对水稻、大豆吸收As具有协同作用;采用腐殖酸4%、pH4处理改性措施使土壤中有效态As含量降低,降低了As对农作物的健康风险.

Effects of As pollutant in soil on crop growth and safety of agricultural products under Cd stress

Pot experiments of rice and soybean plants have been conducted to study the effects of As pollutant under Cd stress on the growth of crops, the absorption of As and the safety of agricultural products of different modifier in As-Cd polluted soils. The results showed that in single As treatment rice plant decreased in height and yield by 10.3 cm and 9.8% respectively compared with control; soybean plant decreased in height and yield by 12 cm and 5.6% respectively compared with control. It is thus evident that As-Cd treatment inhibits the growth and development of the plants. In As-Cd treatment the As contents in root, stalk with leave, grain of rice plant exceeded those of single As treatment by factors of 4.2, 1.14 and 1.7 respectively; the As contents in grain, stalk with leave, root of soybean plant exceeded those of single As treatment by factors of 4.63, 2.82 and 1.85 respectively. For the soybean and rice plants the Cd promote As absorption synergistically. The available fraction of As content in soil was decreased in the treatment of 2% of humic acid, humic acid and acid treatment(soil acidity adjusted to pH 4) could decrease As health risk for crops.