Effect of Nitrogen,Phosphorus and Kalium Coupling on the Yield of Hybrid Cotton under Film Drip Irrigation

【Objective】Effect of N,P and K coupling on growth and output of hybrid cotton under film drip irrigation was studied.【Method】A field experiment was carried out to study the output of cotton by "3414" complete test scheme of N,P and K,and a model equation of fertilizer and yield was set up.【Result】The results showed that the effect of different proportion of N,P and K application was significant on the yield of cotton,the yield was decreased when fertilizer was insufficient or excessively applied,the effect of N on cotton yield was more than P and K.Three-factor-two times equation of N,P and K was Y=4 382.22+5.456 N+1.937 P+6.823 K+0.013 84 NP-0.009 24N2-0.307 5 P2-0.027 72 K2.The best application quantity of nitrogen,phosphorus and kalium fertilizer were respectively 383.26,117.76 and 123.07 kg/hm2 by the model equations,the most yield was 5 961.8 kg/hm2.【Conclusion】 These results suggest that the right combination of N,P and K proportion would lead to high yield,and increase economic benefits.