滇池流域斗南不同土地利用下土壤养分的分布及其对环境的影响

Distribution of Soil Nutrient and its Environmental Impact under Different Land Utilization in Dounan of Dianchi Watershed

在滇池流域斗南村选取5种典型的土地利用方式的25个土壤样品,对土壤中氮、磷和有机质进行对比分析。结果显示,不同土地利用类型氮、磷和有机质含量有明显差别:蔬菜花卉地上的含量都是最高的;其次是抛荒的蔬菜花卉地;作为粮食作物和水土保持措施的小麦地和林地,因为其经济价值较低,投入较少,养分的含量是最低的;流入滇池的旁沟养分含量相对较高,加剧了滇池的富营养化。综上所述,确定距离滇池最近的蔬菜花卉地和抛荒地是滇池的最主要的非点源污染源,从而为滇池污染的治理,合理规划土地利用提供理论依据。

In order to analyze mitrogen, phosphorus and organism in soils under different land-using, 5 typical land-using patterns were chosen and 25 soil samples were collected in Dounan of Dianehi watershed. The trends discovered were as follows： there was distinctive difference in nitrogen, phosphorus and organism in soils under different land utilizations. It was characterized with high contents in vegetable and flower lands, having high correlations with fertilization. The next was in waste land after vegetable and flower planting. Wheat land and woodland were rarely fertilized as food supplies and water and soil conservation because of low value. Soil nutrient was decreasing greatly. However, the soil nutrient was abundant in the channel, which was connected with Dianehi,resuhing in eutrophication in Dianchi lake. It may be suggested that wasteland, vegetable and flower land be major Non-point Source Pollutions. In addition, in the paper the theories base for the control of pollution in ianehi and planning design of land utilization were provided.