施入城市生活垃圾堆肥对玉米植株重金属分布及土壤养分的影响

以玉米为供试作物,研究施入生活垃圾堆肥对土壤和玉米各器官重金属分布规律及对土壤养分的影响。结果表明:连续3年施肥,土壤速效养分的含量明显增加;土壤重金属呈现累积,但含量远远低于二级土壤标准(GB 15618-1995);植株中重金属含量表现为根部>茎秆>叶片>籽粒,Cd在植株根部富集,但未大量向其他部位转移,玉米植株地上部分重金属含量明显低于饲料卫生标准(GB 13078-2001)。由此推断,在短期内(3年),年施入60 000 kg·hm^-2的垃圾堆肥能提高土壤肥力,且暂时不会引起土壤重金属污染,也不影响玉米植株的饲用;使用多年后应及时监测,以保证安全性。

Effect of Municipal Solid Waste(MSW)Compost Application on Heavy Metal Distribution in Maize Plant and Soil Nutrients

Municipal solid waste(MSW)compost is increasingly used in agriculture for improving soil nutrients and reducing waste disposal cost. However,the risks and benefits of MSW remains unsolved. In the present study,a field experiment was conducted to investigate the influence of MSW compost on heavy metal contents and nutrients in soil and of maize plant. The results showed that nutrients and heavy metals in soil were obviously increased,but heavy metal contents did not exceed the soil environmental quality standard of China(GB 15618-1995). Contents of heavy metal in plant showed the order of root stem leaf seed. Heavy metals in aerial part were significantly lower than the feed hygiene standards of China(GB 13078-2001). The results indicated that,as a consequence of annual 60 000 kg·hm^-2MSW application,soil fertility was obviously increased without presence of significant heavy metal pollution in a short term(three year),the aerial part of maize plant was not polluted either and could be used as feed; but continuous application must be timely monitored to keep safety.