Study on Effect of Nitrogen Fertilizer of Cotton in Hubei Province

A study was undertaken to evaluate the effect of nitrogen(N) fertilization on yield,economic benefit,N use efficiency and optimum N recommendation rate of cotton through field trials at 17 sites in Hubei province.The results showed that the yield and profit of cotton significantly increased when N supplied adequately.Compared with the treatment without N fertilizer,the increment of seed-cotton ranged from 131 kg/hm2 to 1 244 kg/hm2,the average increment was 752 kg/hm2 and increased by 31.1 percent compared with the control.The average net profit of the N application was 3 422 Yuan/hm2 and the value cost ratio(VCR) was 4.07.The average partial factor productivity of applied N(PFPN) and agronomic N use efficiency(ANUE) were 13.20 kg/kg(N)and 2.90 kg/kg(N),respectively.According to linear plus platform model,the average optimum N application rate was 114.0 kg(N)/hm2 in Hubei province.