控释肥对农田氮磷流失的影响研究

目的]研究控释肥对农田氮磷流失的影响。方法]通过选取巢湖流域水田作物水稻和旱地作物玉米进行大田试验,分别研究了施用普通复合肥、控释复合肥和减量20%控释复合肥对农田氮磷径流流失与淋溶流失的影响。结果]水稻和玉米氮磷的径流与淋溶流失主要发生在施肥初期,其中径流流失量均占总流失量的98%以上,而淋溶流失部分所占比例均不到2%,说明水稻和玉米营养盐的流失主要通过径流流失。相对于普通复合肥处理组,减量20%控释复合肥处理组水稻田氮磷的总流失量分别降低了60%和63%,玉米地分别降低了27.8%和34%,表明施用控释复合肥能维持作物生长后期较高的土壤养分,提高氮磷的利用效率,有效地减少雨季水稻和玉米的氮磷流失,降低农业面源污染。结论]该研究结果表明控释肥对农田作物养分流失具有减缓作用,为控释肥的大面积推广及减轻农业面源污染等提供了科学依据和技术支撑。

Effects of Controlled Release Fertilizer on Loss of Nitrogen and Phosphorus from Farmland

Objective] The aim was to study on effects of controlled release fertilizer on loss of nitrogen and phosphorus from farmland.Method] Experiment was conducted in fields planted with rice and corn around Chao Lake and effects of compound fertilizer,controlled release fertilizer and controlled release fertilizer(reduced by 20%) on loss of nitrogen and phosphorus through runoff and leaching were analyzed.Result] Loss of nitrogen and phosphorus mainly occurred in early stage of fertilizing;loss caused by runoff accounted for over 98% and caused by leaching was lower than 2%,indicating that nutrients of rice and corn mainly lost through runoff.As for controlled release fertilizers with 20% reduced,total loss of N and P decreased by 60% and 63% in rice field and reduced by 27.8% and 34% in corn field,respectively,indicating that controlled release fertilizer would maintain nutrients in soils high in later period of plants’ growth,improve use efficiency of N and P,reduce N and P loss in rice and corn fields in rainy season,and decrease non-point pollution.Conclusion] The research suggested that controlled release fertilizer would slow down loss of nutrients in farmlands,providing scientific references and technological support for extension of controlled release fertilizer and reduction of agricultural non-point pollution.