我国设施蔬菜产地土壤环境质量问题及管理对策

Problems of Soil Environmental Quality and Their Management Strategies in Greenhouse Vegetable Production of China

        黄标(中国科学院南京土壤研究所/土壤环境和污染修复重点实验室 南京 210008)
        胡文友(中国科学院南京土壤研究所/土壤环境和污染修复重点实验室 南京 210008)
        虞云龙(浙江大学农业与生物技术学院 杭州 310058)
        沈根祥(上海市环境科学院 上海 200233)
        滕应(中国科学院南京土壤研究所/土壤环境和污染修复重点实验室 南京 210008)
        何跃(环境保护部南京环境科学研究所 南京 210042)

         设施农业;土壤环境质量;管理对策

        changes of soil properties;accumulation of pollutants;environmental effects;safety risks;environmental management

        由于设施蔬菜生产复种指数高、农用投入品投入量大、产地环境封闭等特点, 易造成污染物在土壤中积累及有效性增加, 带来生态环境风险。研究表明, 设施蔬菜土壤中农药、剩余养分、重金属、酞酸酯、抗生素等污染物积累明显高于一般大田蔬菜, 其环境与安全风险比常规农田明显要高。土壤性质改变和污染物积累, 可降低土壤的生态功能, 提高作物污染物含量, 影响水体质量, 给设施蔬菜生产系统生态环境安全和人体健康带来风险。其原因与农用投入品投入量过大、生产经营落后、法律法规和标准不适应管理需求、监管缺失等有关。未来需要加强农用投入品使用的监管和指导, 完善适应设施生产的环境质量评价标准体系, 建立设施蔬菜产地环境监管和指导机制, 加大环保科技投入, 以保证设施蔬菜生产得到可持续发展。

        Lately, the greenhouse vegetable production(GVP)is being developed rapidly, the planting area was dramatically increased from 15,000 hectare in 1983 to 4,667,000 hectare in 2013. It has become an important food source for public consumers and incomes for farmers. It is estimated that the vegetable consumption will increase 50% and the demands will increase 75% in 2050. Obviously, the GVP will continue to grow in the future. However, high crop indexes, a large amount of agricultural inputs, and very close space easily result in the accumulation of pollutants and increase of their availability in soil, which bring up the ecological risks of environment. It is necessary to illuminate the problems of soil environmental quality, analyze the reasons of the problems, and put forward the management strategies. The researches and surveys on the changes of soil properties, the accumulation of pollutants, the assessment of pollutant environmental risks, and social-economic and management situations in GVP distributed in most of China were conducted in the past years. Generally, soil pH was increased and salts were accumulated because of intensive utilization over cultivation duration and close space in GVP system. The nutrients in soil were not balanced because of overload of nitrogen(N)and phosphorus(P). The pollutants such as pesticides, remaining nutrients, heavy metals, phthalic ester, and antibiotics are more accumulated in GVP soil than open field vegetable production, whereas soil and their environmental risk are greater in the former soil than in the latter soil. The changes of soil properties such as decreased soil pH, increased soil organic matter, and accumulated pollutants degrade soil ecological function, increase the levels of pollutants in crops, limit crop growth, and deteriorate surrounding water quality through accumulation of N, P, and soluble organic components, bringing up the ecological risks for environmental safety and human health. The reason analysis shows that there are four dominant reasons resulting in the above phenomena. Firstly, the heavy application of agricultural inputs such as pesticides, chemical and organic fertilizers, and plastic mulching film cause the changes of soil properties and the soil accumulation of pollutants, which result in increased availability of pollutants in soil and uptakes in crops. Secondly, the producers'outmoded production capacity and technologies determined that the producer excessively depends on the heavy application of agricultural inputs. Thirdly, present regulations and standards do not meet environmental management needs, for example, some pollutants are not included in the state soil safety standard system. Lastly, up to now, there is no specific sector to take charge of monitoring and managing GVP system under the circumstances of such a rapid development, which is not inadaptable of public's aspiration to safety foods. In the future, in order to assure sustainable development of GVP,(1)supervision to agricultural input uses and agricultural input reduction technology application would be emphasized;(2)improvement of production capacity could gradually be achieved via increased investment and transformation from present small-scale operation to large-scale operation;(3)the system of environmental quality assessing standards being suitable for GVP would be established, including supplement of the standards of specific pollutants, amendment of present standards, and establishment of the regulations on controlling agricultural inputs;(4)monitoring and management to soil environment of GVP would be reinforced through setting up the monitoring and supervising sector and its operating mechanism for GVP by government;(5)investment in research and development of GVP environmental protection would be increased, in order to study in depth the effects of high inputs and quick sprawling in GVP on soil ecological environment and groundwater resources, and to evaluate the utilized potential and environmental carrying capacity. Therefore, the decision-making supporting system on the environmental risk assessment and control is established.