发酵鸡粪和有机磷肥对土壤中Pb、Cd污染的影响

Effects of fermented chicken manure and organic phosphate fertilizer on Pb and Cd pollution in soil

研究了湘西地区常用的发酵鸡粪和有机磷肥施用对不同程度Pb、Cd复合污染土壤中乙三胺五醋酸(DTPA)提取态Pb(DTPA-Pb)、DTPA提取态Cd(DTPA-Cd)和土壤酶的影响,并研究了对于种植黑麦草(Lolium perenne L.)的影响。结果表明:(1)施用发酵鸡粪和有机磷肥均能显著改善土壤酸性,一定程度上提高土壤有机质含量。在加入质量浓度200mg/kg总Pb、2mg/kg总Cd复合污染土壤中施用有机磷肥,能有效钝化土壤DTPA-Pb、DTPA-Cd,但在400mg/kg总Pb、4mg/kg总Cd复合污染土壤中钝化效果有限,其优先钝化DTPA-Pb。施用发酵鸡粪不能有效钝化土壤DTPA-Pb、DTPA-Cd。(2)施用发酵鸡粪和有机磷肥均显著提高黑麦草鲜重。虽然施用有机磷肥能更有效的钝化土壤DTPA-Pb、DTPA-Cd,但对于黑麦草种植而言,施用发酵鸡粪能更有效的降低其对Pb和Cd的积累,并且主要积累到根部。(3)施用发酵鸡粪对土壤碱性磷酸酶活性、脱氢酶活性和脲酶活性有显著的促进作用。综合而言,湘西地区种植牧草黑麦草,施用发酵鸡粪比较合适,能有效改善土壤酸性,提高黑麦草鲜重和土壤酶活性,降低黑麦草对Pb和Cd的积累。

Effects of fermented chicken manure(CM)and organic phosphate fertilizer(PF)application on diethylenetriamine-pentaacetic acid extracted Pb(DTPA-Pb)and diethylenetriaminepentaacetic acid extracted Cd(DTPA-Cd)in different Pb and Cd combined contaminated soils were studied in the western of Hunan,as well as soil enzymes activities.The effects on ryegrass(Lolium perenne L.)were studied,too.Results showed that:(1)both CM and PF applications improved soil acidity,and increased organic matter at a certain degree.PF application decreased soil DTPA-Pb and DTPA-Cd under 200 mg/kg total Pb and 2 mg/kg total Cd added contamination,but this effect was limited under 400 mg/kg total Pb and 4 mg/kg total Cd added contamination.PF application was more effective at immobilizing DTPA-Pb.However,CM application had little heavy metal immobilization effect.(2)Both PF and CM applications significantly increased ryegrass fresh weights.Although PF application had better immobilization on soil DTPA-Pb and DTPA-Cd,CM was more able to decreased Pb and Cd uptake of ryegrass,which accumulated in roots.(3)CM application significantly increased activities of soil alkaline phosphatase,soil dehydrogenase and soil urease.Consequently,CM application was suggested for ryegrass planting in the western of Hunan,since it could improve soil acidity,increase ryegrass fresh weights and soil enzymes acitivities,decrease Pb and Cd accumulation in ryegrass.