寒冷干旱地区施用污泥有机肥对紫花苜蓿草生长和土壤理化性质的影响

Impact of Sludge Organic Fertilizer on the Growth of Alfalfa and the Treated Soils in an Arid Cold Area

采用污泥有机肥对紫花苜蓿草进行施肥作用,研究其对紫花苜蓿草生长和土壤理化性质改变的影响。实验结果表明,相比未施肥对照小区,污泥有机肥对紫花苜蓿草的生长,如株高,茎粗,叶面积,分枝数和茎叶比均有较好的促进作用(P<0.01)。通过对紫花苜蓿草进行分析,发现与未施肥作物相比,叶子中营养元素和微量元素(N、P、K、Zn、Fe、Cu、Mn)含量均有所提高,且未对作物产生毒害作用,同时与土壤中相关元素呈正相关性,在叶子中未发现重金属元素(Pb、As、Cd、Cr)。污泥有机肥施用后,土壤中营养元素,微量元素和重金属元素含量有所增加,其中除重金属Cd含量外(临近标准值),其他元素含量均低于土壤环境质量标准(GB15618―1995)的二级标准。同时土壤中pH、电导率、CaCO3、有机质等指标与未施肥土壤相比也有所提高。试验结果表明,污泥有机肥可以为作物提供充足的营养元素和微量元素,促进作物生长;同时在施用污泥有机肥过程中需要注意土壤中重金属元素Cd的富集情况。

The effects of sludge organic fertilizer fertilization on the growth of alfalfa and the soil were studied and the results were as follows： the growth of alfalfa as indicated by total height,stem diameter,leaf area,shoot number and stern leaf ratio were better than that of stand without fertilization（P0.01）.Plant analysis indicated that concentrations of nutrients and micronutrients（N,P,K,Zn,Fe,Cu,Mn） in leaf under sludge organic fertilizer fertilization than those of alfalfas without fertilization,and positively correlated with their respective values in soil.Heavy metals（Pb,As,Cd,Cr） were not detected in leaf of alfalfa.Application of sludge organic fertilizer resulted in an increase in the concentrations of nutrients,micronutrients and heavy metals in soil.Among these minerals only Cd closed in the limit（GB15618-1995）.The increase of pH,electrical conductivity,CaCO3,organic matter of soil was also observed under sludge organic fertilizer fertilization.So results confirm that sludge organic fertilizer was a potential source of nutrients and micronutrients for plants and promote the growth of alfalfa.However,the accumulation of heavy metals such as Cd in soil needs to be monitored.