Effect of N Fertilization Rate on Pepper Growth,Yield and Its Optimum Application Rate in Greenhouse

A field experiment was conducted to study the effect of different N fertilizer application rate on pepper growth,yield and economic benefit in second generation greenhouse in Ningxia.The results were shown that there were relatively lack of nitrogen in available phosphorus and potassium in the tested soil.The soil is gently salinized due to over fertilization in the greenhouse.N is decisive factor for pepper growth because its height,chlorophyll,diameter of stem,and yield of pepper were significantly affected by increased N application rate.83% of pepper yield relied on N fertilizer application amount.The relationship between N application rate and pepper yield can be described by parabola curve.The maximum application rate of N is 872 kg/hm2.The optimum application rate of N is 791 kg/hm2.