农业种植对水体富营养化的影响

IMPACT OF AGRICULTURE PLANTATION ON WATER RICH ALIMENTATION

该文从农田施用氮磷肥的数量入手,结合土壤中营养物质运移的基本原理,总结了前人报道的太湖湖区水体营养盐来源及比例,阐述了农业种植对水体富营养化贡献的数量与比例。分析认为:每年进入太湖湖区水体的氮素数量不足0.94万t,占总氮排放的10%左右,从农田中直接排出的磷不足83t,约占总排磷量的1.5%。综合分析表明:农业种植中施用的氮磷肥不会对水体造成严重污染,降低环湖农田产量目标、确定氮磷肥合适用量、限制环湖农田蔬菜作物种植是减少农业种植对水体富营养化的重要措施。

Starting with the quantity of nitrogen and phosphorous applied in farm fields and combing with the basic theory of nutritional matter movement in soil, this paper summarizes the source of nutritional salt and ratio in water of Tai Lake region reported by former reporters; expounds the quantity and ratio contributed by agriculture plantation to water rich alimentation. The result indicates that nitrogen entering into Tai Lake every year is less than 94 million t, which accounts for about 10% of the total nitrogen letting amount; phosphorous directly discharged from farm fields is less than 83 t, which accounts for about 1. 5% of the total discharged phosphorous. Analysis indicates that nitrogen and phosphorous fertilizer applied in agriculture plantation can not severely pollute water. Important measures such as： reducing yield target for farm fields surrounding the Lake, fixing suitable quantity of nitrogen and phosphorus fertilizers, and restricting vegetable plantation in farm land around the Lake must be taken, so as to reduce the influence of agriculture farming on water rich alimentation.