Abstract: Field experiments were carried out at Changde in 2014 and 2015 to study the effects of N application rates on NPK uptake, distribution and utilization,cotton yield and fiber quality by applying five levels(0,90,180,270,360 kg/ha)of N fertilization.The results showed that:in the 0-360 kg/ha application range,the accumulation of NPK gradually increased with the increased of nitrogen application;The accumulation and distribution of N were in good agreement with the accumulation and distribution of P and K,the accumulation of NPK in cotton was the largest under the condition of nitrogen 360 kg/ha.In the 90-360 kg/ha application range,the proportion of NPK in boll was the largest under the condition of nitrogen 270 kg/ha.In the 0-360 kg/ha application range,the N use efficiency,the N agronomic use efficiency,the N partial productivity and the N production efficiency decreased with the increased of nitrogen fertilizer,but the absorption of P and K increased with the increased of nitrogen. The biomass accumulation and cotton yield were increased with the increased of nitrogen fertilizer,when the nitrogen level was increased to 270 kg/ha,the effect was no longer significant,both biomass and yield were the highest. In the 0-360 kg/ha application range,the micronaire value was decreased with the increased of nitrogen fertilizer,but there was no significantly change in uniformity and elongation.The highest fiber appropriate amount of nitrogen fertilizer was beneficial to the absorption of NPK,accumulation of strength and length were obtain in 180-270 kg/ha nitrogen application treatment,the biomass,improvement of yield and quality. In this experiment,the amount of nitrogen application was recommended from 250 to 270 kg/ha.

Key words: Cotton, Nitrogen application, Biomass, Accumulation and distribution, Yield, Fiber quality

CLC Number: 

• S143.1