Nitrogen (N) fertilization plays a pivotal role in canopy photosynthetic capacity and yield formation of cotton (Gossypium hirsutum L.), but the interaction effects with consecutive straw returning remain poorly understood. A field experiment was conducted (2015–2018) to examine the effects of N fertilization (0, 75, 150, and 300 kg N ha⁻¹) coupled with or without barley and cotton straw supplementation on soil nutrient status, cotton canopy photosynthetic capacity, seedcotton yield, and nitrogen use efficiency (NUE) in Yancheng, China. N fertilization coupled with straw addition enhanced most cotton growth traits, showing higher canopy apparent photosynthesis rate, leaf area index, leaf N content, specific leaf area, and boll density, and progressively increased seedcotton yield annually. In 2018, straw addition increased seedcotton yield by 7.5 %, 9.6 %, 12.1 %, and 4.1 % under 0, 75, 150, and 300 kg N ha⁻¹, respectively, compared to corresponding treatments of straw removal. The highest increase in seedcotton yield and NUE under 150 kg N ha⁻¹ combined with straw addition was due to the greatest improvements in soil fertility, canopy photosynthetic capacity, and N uptake by cotton. In addition, the results suggested that approx. 33–44 % of chemical N fertilizer reduction would not affect seedcotton yield with straw addition. Our results demonstrated that straw returning combined with 150 kg N ha⁻¹ had benefits on improving soil nutrient status, canopy photosynthetic capacity, seedcotton yield, and NUE of cotton.

氮（N）受精起着棉花群体光合能力和产量形成（关键作用陆地棉L.），但仍然知之甚少具有连续秸秆还田的相互作用的效果。进行了田间试验（2015–2018），以研究氮肥（0、75、150和300 kg N ha ^{-1的影响）}），再加上或不补充大麦和棉秸秆，对盐城地区土壤养分状况，棉花冠层光合能力，籽棉产量和氮利用效率（NUE）的影响。氮肥和秸秆还田可以提高棉花的大多数生长特性，其冠层表观光合作用速率，叶面积指数，叶氮含量，比叶面积和铃密度都较高，并且每年的籽棉产量逐渐增加。与相应的秸秆去除处理相比，2018年，秸秆添加在0、75、150和300 kg N ha ^-1下分别增加了籽棉产量7.5％，9.6％，12.1％和4.1％。在150 kg N ha ^-1以下，籽棉产量和NUE增幅最高加上秸秆还田是由于土壤肥力，冠层光合能力和棉花吸收氮的最大改善。另外，结果表明约。减少33-44％的化学氮肥用量不会影响添加秸秆的棉籽产量。我们的结果表明，秸秆还田与150 kg N ha ^-1的结合对改善土壤养分状况，冠层光合能力，籽棉产量和棉花的NUE都有好处。