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.