Nitrogen is an important element for the growth of flue-cured tobacco and is closely related to its yield and quality. In order to pursue higher economic benefits, excessive fertilizer is generally applied in flue-cured tobacco production, which is unfavourable for the sustainable development of flue-cured tobacco production and for the environment. In 2016 and 2017, experiments using different nitrogen fertilizer application rates in flue-cure tobacco were conducted in Yunnan province, and the changes in agronomic, economic and chemical indices as well as in residual soil nitrogen were compared. Linear and quadratic models were used to compare the response of tobacco to nitrogen fertilizer. With increasing nitrogen fertilizer rate, the proportions of superior to medium tobacco and the average price of flue-cured tobacco leaves initially increased and then decreased, while fresh weight, dry weight and the proportion of inferior tobacco showed the opposite trend. Total sugar and reducing sugar contents decreased with increasing nitrogen fertilizer rates, while total nitrogen and nicotine contents increased. Sensory evaluation scores had the highest value when 90 kg N/ha and 120 kg N/ha were applied. Soil nitrate contents increased as nitrogen fertilizer rate increased. The quadratic model was suitable for the response of cultivar K326 to nitrogen and 90 kg N/ha could meet the needs of cultivar K326.

中文翻译：

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我国烤烟品种K326对氮肥施用量的响应

氮素是烤烟生长的重要元素，与烤烟的产量和品质密切相关。为了追求更高的经济效益，烤烟生产中普遍施肥过量，不利于烤烟生产的可持续发展，也不利于环境。2016年和2017年在云南省进行了烤烟不同氮肥施用量试验，比较了农艺、经济、化学指标以及土壤残留氮的变化。线性和二次模型用于比较烟草对氮肥的反应。随着氮肥施用量的增加，烤烟中优中烟比例和烤烟平均价格先升后降，鲜重、干重和劣烟比例则呈现相反的趋势。总糖和还原糖含量随着氮肥施用量的增加而降低，而总氮和烟碱含量增加。当施用 90 kg N/ha 和 120 kg N/ha 时，感官评价得分最高。土壤硝酸盐含量随着施氮量的增加而增加。二次模型适用于品种K326对氮的响应，90 kg N/ha可以满足品种K326的需要。总糖和还原糖含量随着氮肥施用量的增加而降低，而总氮和烟碱含量增加。当施用 90 kg N/ha 和 120 kg N/ha 时，感官评价得分最高。土壤硝酸盐含量随着施氮量的增加而增加。二次模型适用于品种K326对氮的响应，90 kg N/ha可以满足品种K326的需要。总糖和还原糖含量随着氮肥施用量的增加而降低，而总氮和烟碱含量增加。当施用 90 kg N/ha 和 120 kg N/ha 时，感官评价得分最高。土壤硝酸盐含量随着施氮量的增加而增加。二次模型适用于品种K326对氮的响应，90 kg N/ha可以满足品种K326的需要。