The field experiment was conducted to research the effects and differences of different quantity of water and nitrogen application on cotton yield in two cotton varieties. The results show that the yields of two cotton varieties were increased significantly with the increase of water and nitrogen, but reduced with excessive irrigation water, the maximum cotton yield were obtained with treatment N 2W 2 (N 2: 360 kg/hm 2; W2: 4500 m 3/hm 2). The cotton yield of Biaoza A 1 is significantly higher than that of Xinluzao33, there was no significant difference between in treatment N 1W 1 and N 1W 3, other treatments showed significant difference in cotton yield between the two varieties. These results suggested that the yield and water and fertilizer use efficiency can be enhanced evidently by adopting suitable measures of water and fertilize application based on different cotton varieties.
