Yield effects of water-fertilizer coupling on high-yield cotton under surface irrigation

Based on the design of 3414,with the cotton variety of Zhongmian No.43 as test material in Shaya County,the coupling effects of water and chemical N,P fertilizers and water on cotton yield were studied,and a regressive mathematical model was set up based on the cotton yield by quadratic regression analysis.The results showed that all test coupling levels of water and chemical fertilizers had significant effects on cotton yield.The yield-increasing effect of test factors was in the order of P application rate irrigation amount N application rate,while the coupling effect of water and chemical fertilizers was in the sequence of N and P N and water P and water.For cotton yield,the optimum irrigation amount and application rates of chemical fertilizers were 545.55 kg/hm2 of N and 199.8 kg/hm2 of P and 6429.3 m3/hm2 of water.