Objective To investigate the impact of varying nitrogen fertilizer rates on dry matter, nitrogen accumulation and distribution under the (66+10) cm planting mode, aiming to provide scientific basis for improving cotton nitrogen fertilizer application and high-yield cultivation technology in Bayingolin Mongolian Autonomous Prefecture, Xinjiang.

Methods The field experiment was carried out by using local major cotton varieties Ba 43541 in Korla experimental field during the years 2021 and 2022.The experiment included four treatments with four different nitrogen levels 0, 112.5, 225.0, 337.5 kg/hm². Plant samples at the key growth period were collected to measure the contents of dry matter and nitrogen, analyze the trend of accumulation and distribution of dry matter and nitrogen in cotton and the relationship between the two and their yields.

Results With the development of the growth process, the accumulation of dry matter and nitrogen showed an "S" type increasing trend, the proportion of dry matter and nitrogen in the vegetative organs decreased gradually, while the proportion of reproductive organs increased gradually. With the increase of N application rate, the accumulation of dry matter and nitrogen increased, and the accumulation of dry matter and nitrogen in cotton reached the highest when the nitrogen level was 337.5 kg/hm², but the distribution proportion of reproductive organs was the highest when the nitrogen level was 112.5 kg/hm². The seed cotton yield increased first and then decreased with the increase of nitrogen fertilizer, and the seed cotton yield was the highest when the nitrogen level was 112.5 kg/hm².

Conclusion At different nitrogen levels, the accumulation of nitrogen and dry matter increases with the increase of nitrogen. The nitrogen level of 112.5 kg/hm² is more conducive to the increase of nitrogen and dry matter distribution proportion of cotton reproductive organs, thus leading to the high yield of Ba 43541.