Interception And Transformation Efficiency Of Nitrogen-phosphorus On Different Width Bamboo River Buffer

Eutrophication caused by N(Nitrogen) and P(phosphorus) loss from agricultural field into river is a world-wide environmental problem. Excessive N and P is responsible for eutrophication of river and lake system, lack of Oxygen in water, a large number of animals died, while elevated N in drinking water has consequences for human health. As buffer strips between water and adjacent highland. Surface runoff, soil runoff and nutrient content were reduced by river buffer strips. For ecological benefits and economic benefits of river buffer strips, this study is based on bamboo river buffer strips of Chingning county of Sicuan province, and from agricultural field, hydrology and plant to discuss efficiency of interception and transformation of bamboo river buffer strips. The main results include:(1)The rainfall of the whole year is 973.3mm in experimental area and days of rainfall is 173 which take 47.4% of all the year. Throughfall and stemflow are 586.0mm and 71.7mm respectively, and efficiency of them are 60.2% and 7.4%. Content of N by rainfall is 56.894 kg.hm-2, including throughfall 50.889 kg.hm-2 and stemflow 6.005 kg.hm-2. NH4+ and NO3- are mainly composition in various forms of N element, the content of NO2- only take 1% to 2%. The content of PO43- is very low.(2)Density of artifical Bambusa rigida in buffer strips is 19900 hm-2, and total production is 98672.01 kg.hm-2. Stock of N and P element are 1032.3 kg.hm-2 which is 1.05% of total production. Stock of N is 864.6 kg.hm-2 and Stock of P is 167.7 kg.hm-2.(3)Total content of N and P collected by soil profile from agricultural field is 1315.57mg. When the runoff through 5m, 10m, 20m width buffer strips, the content come down to 617.61mg, 285.52mg and 244.43mg respectively. When the runoff through 30m width buffer strips, the content is 225.76mg which is similar to above result. Interception efficiency of 5m, 10m, 20m, 30m, 40m are 53%, 79%, 81%, 83%, 85% respectively. From this, we believe that 10m to 20m width bamboo river buffer strips play an effective role on preventing N and P into river.