Effect of N Rates on N Uptake,Accumulation and Yield of Cotton with Drip Irrigation under Membrane

A field experiment was carried out to study the effects of N application(0,180,270,360 kg/hm2) on N uptake,accumulation yield and apparent N recovery in cotton with drip irrigation under mulch.The results showed that N fertilizer application significantly increased yield,biomass yield and total N uptake of shoot of cotton in maturity,but over-application of N fertilizer made yield decrease.The N application rate of all N treatments was ranged from 27.6%to 33.8%,which decreased with increasing of N application rates.N content in plant was decreased with the growth stages of cotton,but N accumulation in the tissue showed an upward tendency,N application rates influenced N uptake of cotton plant significantly,both N content and N accumulation were increased with N rates increasing in the same growth stage.The available application N rate for cotton should be controlled about 270 kg/hm2 under the experimental condition.