Effect of Nitrogen Levels on the Growth,Development and Yield of Cotton under Shading Conditions

【Objective】In order to provide a theoretical basis for appropriate nitrogen fertilization in cotton field under fruit-cotton intercropping conditions,this project aims to explore the effect of nitrogen levels on the growth,development and yield of cotton under Shading conditions.【Method】The experiment was conducted by simulating shading environment manually and setting different nitrogen levels,during which,the reproductive process was recorded,agronomic traits,chlorophyll content,net photosynthetic rate,leaf area index,dry matter accumulation and yield were surveyed,and then the difference and relationship between the indexes were analyzed.【Result】After shading,flower and boll stage of cotton was extended,and with the increase of nitrogen levels,the impaction aggravated;plant height,plant breadth and function leaf breadth were impacted,the shape of Nitrogen rates of 320 kg/hm~2(N_1) plant was ideal;the chlorophyll content increased with increasing of nitrogen levels;Nitrogen rates of 320 kg/hm(N_1) could maintain a high net photosynthetic rate,higher leaf area index,more dry matter accumulation,canopy structure was reasonable,and ultimately the highest lint yield,which would be increased by 64.0%and 17.9%respectively than Nitrogen rates of 0 kg/hm~2(N_0) and Nitrogen rates of 480 kg/hm~2(N~2).【Conclusion】The impact of shading on the growth,development and yield of cotton was greater,and the nitrogen rate of 320 kg/hm2 was beneficial to the cotton yield.