柘皋河流域农田土壤氮磷迁移过程的模拟研究

Modeling Research on Transfer Processes of Nitrogen and Phosphorus in Different Farmlands from Zhegao River Watershed

[目的]研究土壤表层氮、磷迁移变化机理。[方法]选取柘皋河流域为试验区,以流域3种主要土地利用类型为研究对象,采用人工模拟降雨方法,在不同施肥量、降雨强度条件下研究了氮、磷在壤中流、渗漏液的迁移规律。[结果]氨氮在土壤中具有很强的吸附和转化能力,迁移深度较小,主要集中在表面;硝氮在土壤中迁移转化的过程与土壤特性及水力条件有着密切的关系。菜地土壤中流中总磷含量平均为0.52 mg/L,远远超出相邻水体(巢湖)中磷含量的控制要求。壤中流、渗漏液中氨氮、硝氮、总氮、有效磷及总磷含量同降雨强度、施肥量密切相关。[结论]除了控制地表径流传输,如何有效抑制壤中流中的氮磷迁移对该区域水环境污染的治理十分关键。

[Objective] The research aimed to study the migration and transformation process of nitrogen and phosphorus in surface soil.[Method]Simulated rainfall experiments were carried out in rice fields,vegetable fields and dry lands from Zhegao River watershed in order to study the characteristics of transfer laws of nitrogen and phosphorus in interflow and leachate under different fertilizer levels and rainfall intensities.[Result] NH3-N had a strong adsorption and transformation in the soil mainly in the surface,while migration and conversion process of NO3-N had a close relationship with hydraulic conditions and soil characteristics.The average concentration of TP in vegetable fields interflow was 0.52 mg/ml,which was far beyond of control requirements of the Chaohu Lake.[Conclusion] Effective control of the migration of nitrogen and phosphorus in interflow in addition to surface runoff was very crucial to water pollution control and management of Zhegao River watershed.