Evaluation Of Cotton Nitrogen Use Efficiency And Fertilizer Application In Xinjiang

In recent years,the test action of formula fertilization by soil according to soil nutrient content determination condition, combined with the fertilizer efficiency test results to determine the cotton fertilization, which greatly improves the utilization of cotton yield and fertilizer, but the production assessment in practice cotton fertilizer utilization rate reached a reasonable level of research.Therefore, through four years experiments to determine the maximum yield of fertilization, and reaching the real internal nitrogen use efficiency of highest cotton yield, as a standard evaluation of xinjiang cotton nitrogen suitability, provide a reference for xinjiang cotton soil testing formula fertilization.(1) It is calculated by one-year experiment and four-year located experiment in the fixed function of fertilizer effect of cotton high yield were 2654.5kg/hm2 and 2670.2 kg/hm2, requires the highest production rate of 381.8kg/hm2 and 367.4 kg/hm2,between 100% and 125% of the recommended amount fertilization rate. Compared with the results of the highest cotton yield from one-year experiment,four-year experiment could get more scientific and more statistical meanings. The highest yield fertilizer is 367.4kg/hm2 in the southern area of Kuerle, the amount of nitrogen in the upper and lower range of 15 kg of nitrogen can maintain a relatively high amount of cotton production.(2) Cotton lint yield of 4-year experiment showed a trend of increase after the first reduce with the increase of the nitrogen uptake.Cotton Nitrogen uptake, Agronomic nitrogen use efficiency, Physiological nitrogen use efficiency, Nitrogen recovery efficiency and Internal nitrogen use efficiency, With the increase of nitrogen application was a significant decreasing trend.The highest yield of nitrogen application rate of nitrogen fertilizer, the optimum Internal nitrogen use efficiency(iNUE) closer to 9.06 kg/kg.Use this value can measure applied nitrogen level is appropriate, is higher than the value that nitrogen deficiency, below this value that excess nitrogen application.(3) The highest yield of nitrogen application rate at 353.8 kg/hm2 the, highest lint yield was 2911.18 kg/hm2, the optimum Internal nitrogen use efficiency(iNUE) was 8.22 kg/kg.(4) The 45 cotton field in Northern xinjiang of the optimum Internal nitrogen use efficiency(iNUE) 9.06 with nitrogen uptake(iNUE) was 276.7 kg/hm2, and this point four years experiments of cotton nitrogen uptake was 300.67 kg/hm2, the nitrogen uptake was 325.76 kg/hm2 in 2015.Comprehensive the above results, the optimum iNUE 9.06 when the amount of nitrogen uptake was 301.04 kg/hm2. In order to obtain the highest yield and the optimum iNUE, cotton requires 301.04 kg/hm2 nitrogen fertilizer.(5) The 45 Cotton Field In the northern xinjiang with the optimum iNUE value 15, between 8.3 to 9.6; there were 13 cotton field with iNUE value exceeds 9.6, the maximum value reached 16.1 iNUE; the low iNUE 17 cotton field values( less than 8.3), the minimum was 5.8.