鸡粪和垃圾有机肥对苋菜生长及土壤重金属积累的影响

采用盆栽试验,在红壤和潮土中分别施入土壤重量5%、10%和15%的鸡粪或垃圾有机肥,研究其对苋菜（Amaranthustricoclor L.）生长、土壤化学性状及重金属含量的影响。结果表明,与对照相比,施入鸡粪或垃圾有机肥显著增加苋菜的鲜重、主根长和株高;土壤有机质、EC值、速效磷和速效钾含量均大幅增加,但土壤全氮含量无明显变化。与对照相比,潮土中施用两类有机肥使苋菜植株Cu和Zn含量分别增加26.3%~36.0%和1.2%~20.3%,但未超出国家食品卫生标准对Cu和Zn的允许含量;Cd、Cr和Pb含量都较对照降低,没有出现积累现象。红壤施用两类有机肥,苋菜植株中Zn、Cd和Pb分别下降42.7%~59.9%、0~48.9%和4.1%~71.3%,达到显著水平。有机肥的施入量为5%时,两类土壤中重金属都没有出现明显积累;当施入量为10%和15%时,两类土壤的Cu、Cd、Cr和Pb含量显著增加,出现明显积累趋势,其中除了施用鸡粪使土壤有效Cu含量下降外,两种有机肥均增加了两类土壤中重金属Zn、Cd、Cr和Pb的有效态含量。试验结果提示,从土壤培肥与环境质量安全综合考虑,有机肥的用量应控制在一个适宜范围内。

Effect of Poultry and Household Garbage Manure on the Growth of Amaranth tricolor L. and Heavy Metal Accumulation in Soils

Excessive application of organic manure could result in potential threat to environment.This study was conducted with pot culture on red earth and fluvo-aquic soil received poultry and household garbage manure with the rates of 5%,10% and 15% of soil weight in order to explore the effects of poultry and household garbage manure on the growth of amaranth（Amaranthus tricoclor L.）and soil chemical proper-ties as well as soil heavy metal content.The results showed that almost all the treatments received organic manure obviously increased the fresh leaf yield,main root length and plant height of amaranth as well as OM,EC,available P and exchangeable K in soils except of soil total N.The Cu and Zn concentrations in amaranth plants on fluvo-aquic soil increased by 26.3%~36.0% and 1.2%~20.3%,respectively,as com-pared with control,but the concentrations didn’t exceed National Food Standard for the permission of Cu and Zn content in vegetables,while the concentrations of Pb,Cr and Cd in amaranth plants decreased.The concentrations of Zn,Pb and Cd in amaranth plants in the treatments received organic manure on red earth decreased by 42.7%~59.9%,0~48.9% and 4.1%~71.3%,respectively,as compared with control（P 0.05）.When the treatments received 5% organic manure on red earth and fluvo-aquic soil no obvious heavy metal accumulation in amaranth plants was found.On the contrary,the treatments received 10% and 15% organic manure could obviously increase the contents of available Zn,Cd,Cr and Pb in red earth and fluvo-aquic soil,except of available Cu in the treatment received poultry on two soils.From the compre-hensive consideration of soil fertility and environmental quality safety,a proper application rate of organic manure is necessary.