菜地土壤氮磷面源污染现状、机制及控制技术

为了提高蔬菜产量，菜农大量施用化肥，菜地氮磷肥用量在一些地区已超过蔬菜实际需求量的数倍;而大多数蔬菜是浅根系和没有庞大根系的作物，菜地土壤已出现明显的氮磷累积现象，从而导致蔬菜作物营养失调，硝酸盐含量严重超标、品质下降，并引起菜地土壤理化性状恶化、地下水硝酸盐污染及地表水富营养化等一系列环境问题.本文综述了菜地土壤氮磷面源污染现状(氮磷累积特征、对水环境及蔬菜污染现状)、污染机制(氮磷来源、转化特征及损失途径)及包括施肥控制技术、应用化学添加剂技术、填闲作物技术、种植制度优化技术、汇源景观组合和生态草带拦截技术等污染控制技术，旨在为菜地土壤氮磷面源污染的深入研究提供借鉴.

Present status, mechanisms, and control techniques of nitrogen and phosphorus non-point source pollution from vegetable fields.

Chemical fertilizers are often excessively applied on vegetable field s to pursue higher yields. In some areas, the fertilization rates are several ti mes of those needed by vegetables. Nitrogen and phosphorous are obviously accumu lated in the vegetable soils, resulting in the malnutrition, excessive nitrate, and poor quality of vegetables. Furthermore, a series of environmental problems, e.g., deterioration of vegetable soil physical and chemical properties, nitrate pollution of groundwater, and eutrophication of surface water, are produced. Th is paper reviewed the present status of nitrogen and phosphorous non-point sour ce pollution from vegetable soils (accumulation characteristics of nitrogen and phosphorous and their pollution risks to water environment and vegetables), poll ution mechanisms (sources, transformation, and losses of nitrogen and phosphorou s), and control techniques (fertilization, chemical addition, nitrogen catch cro p cultivation, optimal planting system, spatial matching of source and sink land scapes, and grass buffer strip technology), aimed to supply references for the f urther study on the nitrogen and phosphorous non-point source pollution from ve getable fields.