砷污染土壤不同比例客土对大豆生长和吸收砷的影响

为探究砷污染土壤的客土修复效果,利用在农业部岳阳实验站的微区试验,研究不同客土比例与方式对砷污染土壤的修复效果及其对大豆生长、吸收砷等的影响。结果表明:污染土壤与客土不同比例混合后能使土壤的砷含量不同程度降低,且其含量降幅与客土比例正相关,相应地,大豆对砷的吸收和累积量随客土比例的增加而减少。与对照(即污染土壤)相比较,污染土壤和清洁土壤比例为60∶40时,大豆地上部总生物量(含茎、叶、荚和籽粒)达到最大值,且根、茎、叶、荚和籽粒的砷含量分别比对照降低30.1%、45.3%、39.8%、66.9%和82.8%;其他不同客土比例处理下,大豆各部位的砷含量均与客土比例存在显著的正相关关系。研究表明,合适比例的客土可以降低土壤和大豆砷含量,并促进大豆生长。

Effects of different soil dressing ratios on soybean growth and absorption of arsenic in arsenic contaminated soil

A field micro-plot experiment was conducted at the Yueyang experimental station at the Ministry of Agriculture of China to determine the effects of different soil-dressing methods, containing different proportions of soil dressing, on soybean growth and arsenic uptake. The results indicated that mixtures of contaminated soil and virgin soil in different proportions can decrease the soil arsenic content to different degrees. Reduction of the arsenic content of soil was positively correlated with the proportion of soil dressing. In addition, soybean arsenic uptake and accumulation also decreased as the proportion of soil dressing increased. Compared with the control(contaminated soil), soil dressing treatment C(mixing proportion V/V=polluted soil:clean soil=60:40) had the highest total aboveground biomass dry weight of soybean stems, leaves, pods, and seeds. Meanwhile, the As content of roots, stems, leaves, pods and seeds were lower than those of the control treatment, by 30.1%, 45.3%, 39.8%, 66.9%, and 82.8%, respectively. Increasing the thickness of the soil dressing also effectively reduced the absorption and accumulation of As in soybean tissues. Correlation analysis showed that As content of soybean tissues with different soil dressing treatments was significantly positively correlated with the soil available As content. These research results provide effective support for soil-dressing remediation of soil contaminated by arsenic and other elements.