施氮量对棉花养分吸收利用及产量和品质的影响

【目的】研究施氮量对棉花产量、养分吸收与分配、氮肥利用率及纤维品质的影响,为棉花生产合理施氮提供理论基础。【方法】以中棉所60号为材料,于2018和2019年连续2年大田试验。设置4个施氮水平(0、112.5、168.75、225 kg/hm²,分别以CK、N₁、N₂、N₃表示),在吐絮期采集植株茎、叶、生殖器官,测定干物质质量和氮磷钾积累量,计算氮肥利用率和棉花产量等指标。【结果】施氮量在0~225 kg/hm²,棉花产量随施氮量的增加而增加;施用氮肥可提高棉花吐絮期氮、磷、钾吸收量,施氮水平在0~168.75 kg/hm²,棉花氮、磷、钾吸收量随施氮量的增加而增加,过量施用氮肥后棉花氮、磷、钾吸收量下降;氮肥利用率以112.5 kg/hm²施氮量最高;施氮量对棉花纤维品质指标影响差异不显著。【结论】综合产量、氮肥利用率、养分吸收、分配及利用和纤维品质等指标,黄河流域棉区推荐施氮量为112.5~168.75 kg/hm²。

Effects of Nitrogen Application Rates on Nutrition Uptake and Utilization,Yield and Fiber Quality of Cotton

【Objective】 The research aims to investigate the effects of nitrogen application rates on cotton yield, nutrient uptake and distribution, nitrogen utilization rate and fiber quality with the view of proving theoretical basis for rational nitrogen application in cotton production.【Method】 Four nitrogen application levels (0, 112.5, 168.75 and 225 kg/hm², expressed by CK, N₁, N₂ and N₃ respectively) were established using cotton variety CCRI 60 in the field during 2018 and 2019. During the boll-opening period, plant samples were collected and separated into stem, leaf and reproductive organs, the dry matter quality, nitrogen, phosphorus and potassium accumulation were investigated, and nitrogen fertilizer utilization rate and cotton yield were calculated.【Result】 The results showed that when the amounts of applied N were ranged from 0-225 kg/hm², the cotton yield increased with the increasing amounts of nitrogen fertilizer. Applying nitrogen fertilizer could increase the uptake of nitrogen, phosphorus and potassium in the boll-opening stage of cotton. When the amounts of applied N ranged from 0-168.75 kg/hm², the nitrogen, phosphorus, potassium uptake of cotton plant increased with the increasing nitrogen application rates. The excessive application of nitrogen fertilizer decreased the uptake of nitrogen, phosphorus, potassium. The utilization rate of nitrogen fertilizer was the highest with the amounts of applied N of 112.5 kg/hm². The nitrogen application rates had no significant effect on cotton fiber quality index.【Conclusion】 Considering the yield, nitrogen utilization, nutrient uptake, distribution and utilization and fiber quality, the recommended amount of nitrogen fertilizer in cotton area of Yellow River Basin was 112.5-168.75 kg/hm².