扫帚菜-白菜轮作对白菜镉吸收的影响

Effects of Kochia scoparia-Brassica rapa rotation on Cd uptake by Brassica rapa

摘要:

通过盆栽和大田试验研究扫帚菜Kochia scoparia对土壤中镉 (Cd) 的富集效率，并利用盆栽试验将其与4个白菜品种进行轮作试验，验证扫帚菜对土壤Cd污染的修复效果。结果表明，扫帚菜各部位富集能力表现为叶>根>茎，富集系数分别为15.07、5.44和2.96；种植扫帚菜后土壤总Cd降低6.02%?13.60%；土壤脲酶和酸性磷酸酶活性也有所提高。盆栽轮作结果表明，扫帚菜-白菜轮作系统中白菜地上部Cd含量与未轮作的对照组相比平均降低17.21%，生物量有略微增加，地上部对Cd的转运系数无明显变化。结果显示，通过扫帚菜与白菜轮作不仅可以增加白菜产量，而且可以有效降低白菜可食部Cd含量，实现边生产边治理的绿色农业理念。

Abstract:

In this study, pot and field experiments were conducted to study the enrichment of soil cadmium by Kochia scoparia. Further, rotations in pot experiments were carried out with four varieties of Brassica rapa to verify the remediation effect of Kochia scoparia on cadmium contamination in soil. The enrichment capacity of Kochia scoparia was leaf > root > stem with bioconcentration factors (BCFCd) of 15.07, 5.44 and 2.96, respectively. The total cadmium in soil decreased by 6.02% to 13.60% after planting Kochia scoparia, and the activities of soil urease and acid phosphatase also increased. The results of pot cultivation shows that the above-ground cadmium content of Brassica rapa in Kochia scoparia-Brassica rapa rotation system decreased by 17.21% on average compared with the control group without rotation, whereas the biomass increased slightly, and the above-ground translocation factors (TFCd) did not change significantly. These results suggest that the rotation of Brassica rapa with Kochia scoparia could increase the yield of Brassica rapa, and effectively reduce the cadmium content in edible parts of Brassica rapa, toward the purpose of realizing the green agricultural concept of “harnessing while producing”.