滇池流域农田氮、磷肥施用现状与评价

Status and Assessment of Fertilizing the Nitrogen Fertilizer and Phosphatic Fertilizer to the Field in Dianchi Watershed

2001年6月至9月分别对流域内晋宁、呈贡、西山、官渡和嵩明调查了365家农户有关化肥施用情况。调查分析和计算表明,每年从种植业流失的化肥中纯氮(N)达2575t,纯磷(P)达218t,蔬菜和花卉地的单位面积氮流失量是水田和旱地的7-20倍。菜地年每公顷流失氮204kg,水田的氮流失量最低,平均每公顷每年流失10kg。磷的流失也以蔬菜、花卉地为最高,蔬菜和花卉地的单位面积磷流失量是水田和旱地的9-10倍。研究结果证明,大量的氮、磷化肥施用,通过地表径流和地下水流入滇池是造成其水体富营养化的重要原因之一[6],随着农业和农村经济的发展,蔬菜、花卉等经济作物在滇池流域的种植面积将会逐年扩大,因氮、磷化肥的施用面造成的氮、磷流失量将会不断加大。为了实现减少氮、磷化肥对滇池的污染,应积极推广精确施肥、平衡施肥等科学施肥技术,提高化肥利用率,减少化肥流失。增施有机肥,降低化肥用量。同时提高农村居民的环境意识,加强环境管理,依法保护农村环境,控制农业面源污染。

Investigation,analyes and calculation show that the pure nitrogen reach 2575 tons,pure phosphorus can reach 218 tons from agriculture in Dianchi watershed every year.The leach nitrogen from per unit soil planting the vegetables and the flowers is 7-12 times to the paddy and the arid land.With the development of agriculture,the area of the soil of planting the vegetables and the flowers in Dianchi watershed will expand year by year,the leach nitrogen amount from the fertilizer will increase.In order to decrease the pollution of the Dianchi lake,we should extend the way of fertilizing to improve the utilization of fertilizer,to decrease the leaching and to use organic fertilizer.At the same time,we also improve the environmental consciousness of the country resident,enhance environmental management,protect country environment,environment,and control non-point source pollution.