靖江市水稻种植期间非点源氮污染负荷计算及控制对策

【作者】 徐志红；

【导师】 王连军； 朱锦清；

【作者基本信息】 南京理工大学 ， 环境工程， 2002， 硕士

【摘要】 目前，我国农业非点源氮污染研究较为滞后，农村非点源氮污染水环境问题日益突出，加强该方面的基础研究及防治技术的开发具有重要的现实意义。 本文采用美国通用土壤流失方程结合靖江市气候、土壤特征、植被覆盖、降雨、地势及人类活动强度确定了各个参数值，在此基础上计算出该市全年的土壤侵蚀量，并推出了水稻种植期间的土壤侵蚀量及由此产生的吸附态氮污染负荷量。 通过对靖江市某典型水稻品种种植期间的施肥、降雨、灌溉、蒸发等进行跟踪观察，并对其降雨径流及田间淹水中氮污染物质进行连续监测，结合模型，推求了该地区降雨径流深度、大田灌溉水量及排水量，最后估算了水稻大田种植期间的溶解态氮污染负荷量。 通过比较，得出了水稻种植期间的氮污染以农田氮肥流失为主、土壤侵蚀为次，其氮污染总量占全年氮污染总量85％以上的结论。在此基础上，提出了以提高氮肥利用率为重点的，减少农村非点源氮污染负荷的控制对策。更多还原

【Abstract】 The study of Non- Point -Source (NFS) nitrogen contamination in our country is relatively underdeveloped. Especially, the watershed environmental problem associated with NFS nitrogen contamination in rural area is getting worse. Therefore it is of practical importance to enhance both basic science research and development of protection techniques on this.In this paper, based on Universal Soil Loss Equation (USLE) and local conditions in Jing j iang city with its climate, soil properties, vegetation, precipitation, topography and human activities, model parameters are determined, and the city annual amount of soil-erosion is then calculated. Specifically, the amount of soil-erosion during the period of paddy planting is derived as well as the induced nitrogen-contaminated amount in the absorbed state.A typical paddy species in Jingjiang city is traced through its growing period for its fertilization, precipitation, irrigation and evaporation. The mass of nitrogen contamination in the flowing path and field-water is continuously monitored. Data is then input to the model, and the depth of precipitation flowing path in this area is obtained as well as the amount of field irrigation and drainage . Finally, the dissolved nitrogen contamination amount is estimated for the paddy-growing period.To conclude, the nitrogen contamination of paddy planting is mainly from the loss of agricultural field nitrogen fertilizer. The secondary attribution is the soil erosion. The total amount of nitrogen contamination from paddy-planting could consist of 85% of the total amount of annual nitrogen contamination [in this area] . Based on this analysis, means is proposed to improve the efficiency of the nitrogen fertilizer use and reduce the rural non-point-source nitrogen contamination.更多还原