太湖流域周铁镇土壤氮污染特征研究(8900字)
摘 要：太湖是我国的第三大淡水湖，目前主要环境问题是水体富营养化，而氮、磷是主要限制因子。近年来，工业点源的污染治理力度加大，但太湖水体富营养化程度并没有明显的减轻，水质恶化依然严重，这说明非点源污染己经成为水环境的主要污染源。而在各种非点源污染中氮，有很大一部分来源于土壤流失和淋失。本文通过查阅大量相关文献，以江苏宜兴市周铁镇为研究区，通过对周铁镇土壤理化性质及氮含量的测定，结果表明：周铁镇土壤受到不同程度的氮污染，周铁镇土壤总氮的分布特征是地理位置离太湖距离越近，土壤中总氮含量越高；且地理位置离太湖越近，土壤总氮变化幅度越大周铁镇北部土壤中总氮一般比南部高，土地利用类型对土壤中总氮的含量影响不大，但采样区所处的地理位置却影响很大，周铁镇不同土地利用类型中的硝氮和氨氮含量分布特征是不同的，在周铁镇选择的四种不同土地利用类型作为考察对象中，硝氮在蔬菜地中的含量是最高的，含量按降序排列依次是稻麦轮作、林地和葡萄园；氨氮在林地中的含量是最高的，含量按降序排列依次是葡萄园、蔬菜地和稻麦轮作，在周铁镇选择的四土地利用类型考察对象中，土壤氮肥流失量最高是果园（林地与葡萄园并为果园），按降序排列依次是水稻田、蔬菜地，年流失量依次为2.78 kg/acre、1.36 kg/acre和0.06 kg/acre。
关键词：太湖流域；周铁镇；土壤氮污染
Study on Distribution Characteristics of Soil Nitrogen around Zhoutie of Tai Lake region
Abstract: Tai lake, the third largest freshwater lake in China, is confronted with a severe problem, that is water eutrophication, and nitrogen and phosphorus are the main limit factor. In recent years, the management to the pollution in industrial point source has been strengthened, but there is no obvious sign shows the water eutrophication has been mitigated and water deteriorating is still serious. It makes a conclutions that non-point source pollution has become the main pollution source of the water circumstance. In all kinds of non-point source pollution, nitrogen mainly comes from soil losses and leaching. This article takes the Zhoutie Town in Yixing City of Jiangsu province as the example. After consulting many related articles and testing the soil's physicochemical property and its nitrogen content, I find that the soil in Zhoutie Town has been polluted in different degrees. The feature of the nitrogen's distribution is that the closer to the Tai lake, the higher the nitrogen content and the more the nitrogen content range in the soil is. Generally, the nitrogen content in north is higher than in the south and the land use pattern doesn't have a big influence on the nitrogen content, but the position of the sampling area does. The distribution feature of nitric nitrogen and ammonia nitrogen content is different. Based on four different land use patterns in Zhoutie Town, nitric nitrogen content in vegetable field is the highest, and the order of the content from high to low is Rice-wheat rotation area, woodland and grapery. Ammonia nitrogen content in woodland is the highest and the decending order is grapery, vegetable field and Rice-wheat rotation area. In the four land use patterns, the nitrogen loses most in orchard ( include woodland and grapery ), then is paddy field，and then is vegetable field, and the losses each year is 2.78 kg/acre, 1.36 kg/acre and 0.06 kg/acre in proper order.
Key word: Tai Lake Watershed, Zhoutie Town, Soil-Nitrogen Pollution
目 录
摘要……………………………………………………………………………………1
关键词…………………………………………………………………………………1
1 前言…………………………………………………………………………………2
2 材料与方法…………………………………………………………………………3
2.1 研究区概况………………………………………………………………………3
2.2 样品的采集与预处理……………………………………………………………4
2.3 氮的测定方法……………………………………………………………………5
2.3.1 土壤含水率的测定方法………………………………………………………5
2.3.2 土壤硝氮的测定方法…………………………………………………………5
2.3.3 土壤氨氮的测定方法…………………………………………………………5
2.3.4 总氮的测定方法………………………………………………………………5
3 结果与分析…………………………………………………………………………5
3.1 土壤中总氮水平的分布特征……………………………………………………5
3.2土壤中硝态氮的分布特征……………………………………………………6
3.3土壤中氨态氮的分布特征………………………………………………………7
3.4 不同土地利用类型硝态氮的分布特征…………………………………………7
3.5 不同土地利用类型氨态氮的分布特征…………………………………………8
3.6氨氮、硝氮分别占总氮的比例……………………………………………………9
3.7周铁镇土壤氮污染年排放量估算…………………………………………………9
4 讨论 ………………………………………………………………………………10
5 结论………………………………………………………………………………11
参考文献………………………………………………………………………………11
致谢……………………………………………………………………………………13
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