有机肥对Cd、Pb复合污染酸性土壤生物特性和油菜生长的影响

采用盆栽试验,研究了不同添加量(0、2.5%、5.0%、10.0%)有机肥对镉(Cd)、铅(Pb)重金属污染酸性土壤生物特性和油菜生长的影响,以期为阻控Cd、Pb迁移和油菜安全生产提供技术指导。结果表明,土壤p H值、酶活性(过氧化氢酶、脲酶、磷酸酶、多酚氧化酶和淀粉酶活性)、微生物多样性及油菜生物量总体上均随有机肥添加量的增加而显著增加,而土壤中Cd、Pb有效态含量及油菜各组织重金属含量均随有机肥添加量的增加而降低,10.0%有机肥处理效果最好;主成分分析结果表明,有机肥改良处理的聚类结果与油菜的生长及土壤各项指标的变化规律相吻合;在各项指标中,影响油菜生长的主要因子为Pb有效态含量,其次为Cd有效态含量,说明降低土壤中重金属有效态含量可以有效缓解对作物的毒害。

Effect of Organic Manure on Rape Growth and Biological Characteristics of Lead and Cadmium Contaminated Acid Soil

In a pot experiment,the dose-response effects of organic manure(mass fractions 0,2.5%,5.0% and 10.0%) on the growth performance of rape and biological characteristics of lead(Pb) and cadmium(Cd) contaminated soil were studied,so as to provide technical guidance for control migration of cadmium and lead and rape safety production.The soil pH value,enzyme activities(catalase,urease,phosphatase,polyphenol oxidase and amylase activities),microbial diversity and the biomass of rape were significantly enhanced with the increase of application amount of organic manure,available contents of Cd,Pb and metal content in the plant each part were decreased with the increase of application amount of organic manure.The effect of 10.0% organic manure treatment was the best.Principal component analysis(PCA) revealed that the result of clustering of organic manure treatments accorded with the law of the changes in biomass of rape and soil biological characteristics.Among the growth indices of rape and soil biological characteristics,available content of Pb was the major contributor to inhibit the plant growth,the second was available content of Cd which could effectively relieve toxicity of crops by reducing the contents of available heavy metals in soils.