1Shunyi District Institute of Agricultural Sciences，Beijing 101300，China|2Institute of Plant Nutrition and Resources，Beijing Academy of Agriculture and Forestry Sciences，Beijing 100097，China
Abstract：The effects of 5 nitrogen levels on soil nitrate contents，color pepper（Capsicum annuum L.）production and economic benefits were studied under the greenhouse cultivation conditions with integration of water and fertilizer．The results showed that the soil nitrate contents in soil layer 0-20 cm were higher than that of soil layer 20-100 cm for different nitrogen levels．Along with the increasing amount of applied nitrogen fertilizer，soil nitrate contents of different soil layers and soil nitrate accumulation at 0-100 cm depth showed significantly increased trend．Under 0.225 t hm-1 N levels（medium N），the greenhouse pepper production，its economic benefit and unit nitrogen increased were the highest．
