苋菜对耕作地重金属的吸收研究

Study on Absorption of Heavy Metals by Amaranth in Hunan Cultivated Land

根据前期研究可知苋菜具有吸收土壤重金属污染物的作用,为此选择8个不同苋菜品种为试验对象,以湖南省典型耕作地为试验土壤,研究苋菜对土壤重金属的吸收作用。结果表明:(1)苋菜对耕作地中的多种重金属均有一定吸收作用,从而使土壤中重金属含量下降,下降率大小依次为:锰(Mn)>镉(Cd)>砷(As)>铅(Pb)>汞(Hg)>铬(Cr);(2)连续2 a定期种植红圆叶苋菜后的土壤重金属含量<种植1 a红圆叶苋菜后的土壤重金属含量<未种植红圆叶苋菜土壤重金属含量,连续2 a种植红圆叶苋菜对耕作地重金属污染等级具有持续降低能力;(3)8个苋菜品种对Cd的富集系数均大于1,仅赣科大圆叶红苋菜品种对Mn的富集系数大于1,种植苋菜前后Mn在苋菜中和土壤中的含量变化差异不显著,筛选出综合吸收能力最优的品种为红圆叶苋菜。研究结果表明种植苋菜能显著降低耕作地中重金属含量,减轻重金属污染程度,起到修复土壤重金属污染的作用。

According to previous studies,amaranth can absorb heavy metal pollutants in soil.For this reason,eight different amaranth varieties were selected as experimental objects,and typical cultivated land in Hunan Province was used as experimental soil to study the absorption of heavy metals in soil by amaranth.The results are as follows:(1)Amaranth can absorb many kinds of heavy metals in cultivated land to a certain extent,so that the content of heavy metals in soil decreases.The descending rates are manganese(Mn)>cadmium(Cd)>arsenic(As)>lead(Pb)>mercury(Hg)>chromium(Cr);(2)the contents of heavy metals in the soil after planting Hongyuanye Amaranth regularly for two consecutive years<after planting Hongyuanye Amaranth for one year<no planting Hongyuanye Amaranth;planting Hongyuanye Amaranth in succession for 2 years can continuously reduce the pollution level of heavy metals in cultivated land.(3)The enrichment coefficients of Cd in eight amaranth cultivars were all greater than 1,followed by Gankedayuanye Amaranth cultivars.There was no significant difference in the content of Mn in amaranth and soil before and after planting amaranth.The best comprehensive absorption ability was found to be Hongyuanye Amaranth.The results showed that amaranth planting could significantly reduce the content of heavy metals in cultivated land,reduce the degree of heavy metal pollution,and play a role in remediation of soil heavy metal pollution.