Coupling Effect of Water and Nitrogen on Cotton Nitrogen Use Efficiency under Different Patterns of Mulched Drip Irrigation

LI Pei-ling; ZHANG Fu-cang; JIA Yun-gang

Abstract：This paper studied the coupling effect on cotton yield and natirogen use efficiency (NUE) in different levels of water and nitrogen under different drip irrigation patterns. The factor of water and nitrogen in different drip irrigation patterns that includ 1 pipe-4 lines, 2 pipes-4 lines and 2 pipes-6 lines, field experiments were con-ducted using universal design of the second rotation. The result show that the effect of water and nitrogen on cot-ton, water was more significantly than nitrogen under 1 pipe-4 lines, nitrogen was more significantly than water under 2 pipes-4 lines and 2 pipes-6 lines. To a certain level of nitrogen, 1 pipe-4 lines were positive correlation be-tween nitrogen and cotton yield, 2 pipes-4 lines negative correlation in the applied nitrogen of 27. 6~69 kg/hm~2 and positive correlation in the nitrogen of 69~94. 2 kg/hm~2, 2 pipes-6 lines positive correlation in 27. 6~55. 2 kg/hm~2 and negative correlation in 55. 2~94. 2 kg/hm~2. In a certain level of water, three drip irrigation patterns were positive correlation between cotton yield and water. The coupling effect of water and nitrogen on nitrogen use efficiency (NUE), nitrogen was more significantly than water under the three drip irrigation patterns. 1 pipe-4 lines and 2 pipes-4 lines were negative correlation between cotton yield and the applied nitrogen in 27. 6~82. 2 kg/hm~2 and positive correlation in 82. 2~94. 2 kg/hm~2. 2 pipes-6 lines were negative correlation between cotton yield and the applied nitrogen. The three drip irrigation patterns were positive correlation between water and cotton yield. According to different patterns of drip irrigation water and nitrogen coupling effect, and establish a cotton yield, NUE for the objectives of the different mode of drip irrigation water and nitrogen management strategy.