黑豆—油菜与大豆—油菜轮作模式土壤镉修复能力比较

通过设置黑豆-油菜、大豆-油菜的轮作模式在湖南醴陵进行大田试验,结果发现黑豆表现出较强的镉富集能力,其根、茎、叶及果壳中镉含量分别为2.14、2.63、4.10及1.34 mg/kg,富集系数均在1以上。油菜各个部位镉含量较高的分别为叶与茎,达到了7.13和4.73 mg/kg。黑豆各部位镉转运系数均高于大豆,各油料作物提取的重金属主要集中在茎与叶。大豆叶的镉富集系数为2.06,茎的镉富集系数为0.86,明显低于黑豆同部位的富集能力。每公顷土地经过一轮黑豆-油菜、大豆-油菜轮作分别能够从土壤中提取73.52 g和51.68 g的镉,对土壤重金属镉的修复效率约为3%。

Comparison of Soil Cadmium Remediation Ability Between Black Bean-Rapeseed and Soybean-Rapeseed Rotation Mode

The field experiment was carried out in Liling,Hunan Province by setting the rotation pattern of black bean-canola and soybean-canola.It was found that black beans showed strong enrichment ability for cadmium.The Cd contents in roots,stems,leaves and shells were 2.14,2.63,4.10 and 1.34 mg/kg,respectively,with bioconcentration factor above1.The contents of leaves and stems in different parts of rape were 7.13 and 4.73 mg/kg respectively.Transport coefficient of black soybean was higher than that of soybean.Heavy metals extracted from oil crops were mainly concentrated in stems and leaves.The leaf bioconcentration factor of soybean is 2.06,and the stem bioconcentration factor of soybean is 0.86,which is significantly lower than that of black soybean.A round of black Soybean-Rape rotation can extract 73.52 g/hm^2 and 51.68 g/hm^2 of cadmium from the soil,and the phytoremediation efficiency of Cd in soil is about 3%.