改良剂施用对重金属污染土壤溶液化学性质及豇豆生理特性的影响研究

Amendments on Chemical Characteristics of Soil Solution in Heavy Metal Contaminated Soil and on Physiological Characteristics of Cowpea

本文研究了在不同生长时期凹凸棒土、硅藻土、泥炭、腐植酸对土壤重金属的钝化及豇豆生理特性的影响。结果表明:由于土壤的缓冲性,4种改良剂对土壤溶液pH影响较小;泥炭、腐植酸对Zn、Cu的钝化效果比凹凸棒土、硅藻土好,但4种改良剂对土壤溶液Pb和Cd浓度影响不明显;腐植酸、凹凸棒土均在不同程度上提高了豇豆叶片超氧化物歧化酶、过氧化物酶的活性,其中腐植酸的作用最为明显。除泥炭外,3种改良剂均使豇豆叶片的丙二醛、脯氨酸含量降低。受叶片衰老的影响,成熟期各改良剂对豇豆生理特性的作用不如苗期明显;冗余分析表明:4种改良剂对重金属的钝化效果依次为腐植酸、泥炭、凹凸棒土、硅藻土。本次试验结果说明有机物料腐植酸、泥炭可作为缓解豇豆重金属Zn、Cu胁迫的改良剂。

The influence of four kinds of amendments on physiological characteristics of cowpea and soil solution heavy metal concentrations at different growth stages were studied with pot experiments.The results showed that four amendments had no significant effect on pH value in soil solution because of soil buffer capacity.Peat and humic acid were more effective than palygorskite and diatomite in decreasing soil solution Zn and Cu concentrations,but no significant difference was found in Pb and Cd among four amendments.Peat,palygorskite,particularly humic acid,increased the activity of SOD and POD in cowpea leaves.The amendments except peat decreased the contents of MDA and proline in the leaves.The effects of amendments on physiological characteristics of cowpea were significantly weakened at the mature stage as a result of leaf senescence.Redundancy analysis indicated the inactivation effects of four amendments were in an order of humic acidpeatpalygorskitediatomite.