洞庭湖退田还湖区畜牧业资源与环境评估

EVALUATION ON RESOURCES AND ENVIRONMENT OF ANIMAL HUSBANDRY IN DONGTING LAKE

以洞庭湖流域3个选择畜牧业为替代产业的退田还湖示范堤垸为例,以氟、铬、镉、铅、汞和砷为主要检测指标,参照国家标准,分别对示范堤垸内与畜牧业密切相关的水、土壤与饲草饲料的质量进行了评估。结果表明,示范堤垸水环境化学指标除了大肠杆菌群落外,其余基本达到了无公害和绿色食品卫生标准中关于农田灌溉用水和养殖用水的规定;土壤中铬、镉、铅、汞和砷与氟的背景值均低于无公害和绿色食品标准规定的产地土壤环境指标;大部分饲料、饲草原料中氟、铬、镉、铅、汞和砷含量符合无公害或绿色食品卫生标准。示范堤垸水、土和饲料资源的良好环境背景状况为畜牧业向绿色或有机畜牧业方向发展奠定了自然条件与资源的基础。

A serial programme of ecological restoration for lake recovery and flood control were implemented, and a large amount of land resources were lost for farmers. In Dongting lake region, the farmers who implemented the project of lake recovery and flood control only had limited land resources,and animal husbandry has been chosen as a principle substitute industry in the demonstrative region of Yuanjiang and Hanshou county. The objectives of this paper are to probe the feasibility of developing green and organic animal husbandry. The results showed that the major indexes of sampling water are lower than those of the state sanitation standard of non-public hazard and green food on irrigating and feeding water except the coliform. The background values of heavy metals and fluorine in soil were also lower than those of the state sanitation standard of non-public hazard and green food in soil environmental background .The indexes of trace elements and heavy metals and fluorine of major feedstuffs and forages were lower than those of the state sanitation standard of non-public hazard and green food on feedstuffs and forages. At present, the higher copper, zinc, arsenic and chromium premixes were popularly used in the complete rations or supplements, and the environment and animal products could be influenced by the abusement of feed additives. On the other hand, a minority of feedstuffs and forages which has the ability of largely absorbing trace elements and heavy metals may provide the possibility to formulate reasonablely animal rations satisfied with the requirements of livestock and poultry. Furthermore, it is not necessary to supplement inorganic and organic trace elements in the complete ration in the future. It was found out that coliform populations were higher than those of the state standard, resulted possibly from implementing directly animal and human wastes into the field. So it is necessary to enhance the management of animal waste.