以2019年玉溪烟区9个植烟县34个主要植烟乡镇各1个代表性烟田的土壤和烤烟为研究对象，分析了土壤速效钾和有效镁及其交互作用对烤烟化学及感官品质的影响。结果表明：土壤速效钾和有效镁平均含量分别为325.9 mg/kg和207.9 mg/kg，变幅分别为93.0~713.0 mg/kg和40.0~610.0 mg/kg，土壤速效钾和有效镁缺乏的烟田分别占14.7%和23.5%。随着土壤速效钾含量的增加，烟叶钾含量先增后减，烟叶镁含量递增，烟碱和总氮含量先降后增，总糖含量、还原糖含量、糖碱比和氮碱比递减，其中土壤速效钾含量与烟叶镁含量呈显著正相关（P<0.05）。随土壤有效镁含量的增加，烟叶钾含量递减，烟叶镁含量递增，烟碱含量先增后降，总氮含量递增，总糖含量、还原糖含量、糖碱比和氮碱比先降后增，其中土壤有效镁含量与烟叶钾、镁含量分别呈极显著负相关和正相关（P<0.01）。土壤速效钾和有效镁含量的增加能分别显著提升烟叶清甜香和香气量（P<0.05）。土壤钾镁交互作用对烟叶总糖、还原糖含量及氮碱比均产生显著影响（P<0.05）。因此，为提升玉溪烤烟品质，应在适当施用镁肥的基础上增施钾肥，并同时关注氮肥等其他肥料对烤烟钾镁的影响。

In 2019, soil and flue-cured tobacco leave samples were collected from 34 typical fields in 34 major tobacco-planting towns in 9 tobacco-planting counties in Yuxi City, soil rapidly available potassium (RAK) and available magnesium (AMg) and their interactions on the chemical and sensory qualities of tobacco leaves were determined and analyzed. The results showed that RAK and AMg ranged in 93.0-713.0 mg/kg and 40.0-610.0 mg/kg with a mean of 325.9 and 207.9 mg/kg, respectively. The percentages of fields deficient in RAK and AMg were 14.7% and 23.5%, respectively. With the increase of soil RAK, K of tobacco leaves increased and then decreased, while Mg of tobacco leaves increased, nicotine and total nitrogen of tobacco leaves decreased and then increased, and total sugar, reducing sugar, sugar-nicotine ratio and nitrogen-nicotine ratio of tobacco leaves are decreased, in which soil RAK and Mg of tobacco leaves showed a significant positive correlation (P<0.05). With the increase of soil AMg, K of tobacco leaves decreased, Mg of tobacco leaves increased, nicotine of tobacco leaves increased and then decreased, total nitrogen of tobacco leaves increased, total sugar, reducing sugar, sugar-nicotine ratio and nitrogen-nicotine ratio of tobacco leaves decreased and then increased, among which soil AMg was negatively and positively correlated with K and Mg of tobacco leaves, respectively (P<0.01). The increase in soil RAK and AMg significantly enhanced the style of clear sweet aroma and aroma content of tobacco leaves (P<0.05), respectively. Soil RAK-AMg interaction had a significant effect on total sugars, reducing sugars and nitrogen-nicotine ratio of tobacco leaves (P<0.05). Hence, to improve the quality of Yuxi tobacco leaves, additional K fertilizer should be applied on the basis of appropriate Mg fertilizer, and attention should also be paid to the effect of other fertilizers such as N fertilizer on K and Mg of tobacco leaves.

S158.3;S159.2;S572

红塔烟草（集团）有限责任公司科技项目（S-6019001）和中国科学院战略性先导科技专项（XDA13020601）资助。