The Response Of The Yield And Quality Of Early Maturing Upland Cotton In Xinjiang To The Change Of Fertilizer Application

Xinjiang has the resource advantage of developing cotton and is the most important high-quality cotton producing area in China.The rapid development of cotton production in Xinjiang has been achieved under the condition of continuous breakthroughs in new technologies and new varieties of cotton planting.In particular,in recent years,the amount of fertilizer input has increased rapidly,and the increase of fertilizer input in the physical and chemical cost of cotton production has led to the decline in cotton planting efficiency and reduced comparative advantages.The problem of excessive fertilization in cotton production not only increases the planting cost,but also pollutes the farmland ecosystem and reduces the soil quality.Therefore,under the condition of maintaining the current cotton yield per unit area,it is of great significance to optimize the comprehensive technology of efficient utilization of fertilizer and select cotton varieties with higher utilization rate of nitrogen,phosphorus and potassium to realize the production goals of high quality,high yield,low cost and environmental friendliness of cotton.Based on the currently promoting early upland cotton varieties in Xinjiang as the object,to carry out research on the effects of different fertilizer application on cotton yield and quality,which set high fertilizer(fertilizing amount of N,P₂O₅ is 193.2 kg/hm² is 138 kg/hm²,K₂O is 85.5 kg/hm²,are existing in the Fertilizing amount applied in conventional production,low fertilizer?50%of the fertilizing amount for high fertilizer processing?,no fertilizer?control?three processing,choose early upland cotton varieties in Xinjiang,Xinluzao 45,Xinluzao 57,Xinluzao 61,Xinluzao 64,Xinluzao 72,Xinluzao 74,a total of 6,The response of yield and quality of different varieties to the amount of fertilizer applied was investigated,and the cotton varieties with high nutrient utilization were screened to provide reference for the high quality and efficient production of cotton under fertilizer reduction.The study reached the following conclusions:1.Effects of different fertilizer application on agronomic characters,yield and quality of cotton.plant height,branch number,internode length,first branch height and stem diameter had the least sensitivity to the amount of fertilizer applied,which were Xinluzao 45,Xinluzao72,Xinluzao 45,Xinluzao 72 and Xinluzao 45,respectively.boll number per plant,boll weigh,lint percent,seed cotton yield had the least sensitivity to the amount of fertilizer applied,which were Xinluzao 45,Xinluzao 64,Xinluzao 64 and Xinluzao 45,respectively.upper half mean length,Fiber strength,Micronaire,uniformity index and fiber elongation had the least sensitivity to the amount of fertilizer applied,which were Xinluzao 61,Xinluzao 64,Xinluzao 64,Xinluzao 45 and Xinluzao 61,respectively.2.Effects of different fertilizer application on dry matter accumulation,distribution and nutrient absorption in cotton.The results showed that the dry matter accumulation capacity of Xinluzao 74 was the strongest,and the dry matter distribution rate of Xinluzao 72 to reproductive organs was the highest.The distribution rate of 6 early-maturing upland cotton varieties was 50.25%-72.07%at the wadding stage.NPK is mainly distributed in reproductive organs.Xinluzao 61 had a high nutrient accumulation under different fertilizer application rates,and the nutrient content was shown as total potassium>total nitrogen>total phosphorus in both reproductive organs and vegetative organs under different treatment conditions.3.Effects of different fertilizer application rates on photosynthetic characteristics and canopy structure of cotton.The results showed that the net photosynthetic rate decreased slowly with the increase of fertilizer application.The photosynthetic rate of the unfertilized population in the early stage?about 82 days after seedling emergence?showed a continuous trend of decline.With the increase of fertilizer application,the variation range of photosynthetic rate of the population before and after the peak period increased.With the increase of fertilizer application,the chlorophyll content increased in the early stage and the decline rate accelerated in the later stage.The increase of fertilizer application slowed down the decline rate of overall canopy light interception,but accelerated the decline rate of leaf area index.Xinluzao 57 and Xinluzao 64 had strong photosynthetic capacity.