施用不同畜禽粪便土壤剖面中重金属分布特征

针对不同粪便集中施用情况, 选取禹城市3 个畜禽养殖区, 通过采集不同旱地农田土壤剖面样品, 研究典型重金属元素随粪便施用程度的变化、土壤剖面中重金属垂直分布特征以及施用不同畜禽粪便土壤剖面中重金属分布的差异。结果发现,长期施用畜禽粪便土壤剖面中重金属Cu、Zn、Pb、Cr、As的含量要高于未施用畜禽粪便的对照土壤剖面, 其中Cu、Zn 超过对照组较大;偶尔施用畜禽粪便土壤剖面Cu、Zn、Pb、Cr、As 的含量低于长期施用畜禽粪便土壤剖面, 且与未施用畜禽粪便的对照土壤剖面相差不大。牛粪集中施用区土壤剖面中Cu、Pb、Cr、Cd、Ni 等重金属存在较为明显的淋溶下移性, Hg、As两元素存在较为明显的表层或亚表层聚集现象;猪粪集中施用区土壤剖面各重金属除Cr、Ni 外, 都显示出较为明显的表层或亚表层聚集现象;鸡粪集中施用区的土壤剖面Cu、Pb、Cd、Cr、Ni 存在一定的淋溶下移性, 而Zn、Hg、As等3 种元素存在显著表层亚表层聚集现象。长期施用不同畜禽粪便的不同土壤剖面Cr、Ni、Cd、Pb 等含量变化差异明显, 而As、Hg差异性不显著;施牛粪与施鸡粪剖面中的Zn, 施猪粪与施鸡粪剖面中的Cu差异也不显著。

Characteristics of the Distribution of Heavy Metals in the Profiles of the Soils Fertilized with Different Livestock Manures

Based on the source of different livestock manure, three livestock areas in Yucheng city are selected, and different soil profiles are collected. The heavy metals in the soil profiles are monitored from three aspects as following: variations of heavy metals with various extent of livestock manure application, characteristics of the vertical distribution of heavy metals in the soil profiles, and differences in the vertical distributions of heavy metals in soils fertilized with different livestock manures. As shown in the results, (1) the pollution level of Cu, Zn, Pb, Cr and As in the profiles of the soil with continuous long-term application of manure is higher than that in the profiles of control soil, with Cu and Zn in even more excessive amount. The content of Cu, Zn, Pb, Cr and As in the profiles of the soil with intermittent applications of manure is less than that in the profiles of the soil with contentious long-term application of manure, but shows little difference from that in the profiles of control soil. (2) Cu, Pb, Cr, Cd and Ni in profiles of the soil fertilized with cow dung clearly show downward leaching, but Hg and As concentrate in the surface or sub-surface layer of the soil. With exception of Cr and Ni, other heavy metals in the profiles of the soil fertilized with pig dung concentrate in the surface or sub-surface layer as well. Cu, Pb, Cd, Cr and Ni leach down in the soil fertilized with chicken manure. Zn, Hg and As, however, show significant enrichment in the surface or sub-surface layer. (3) Cr, Ni, Cd and Pb show clear variations in the soils fertilized with different livestock manures, while As and Hg show insignificant variations. There is no difference in Zn between the soils fertilized with cow dung and chicken manure, and there is no difference in Cu between the soils fertilized with pig excrement and chicken manure.