玉溪烟区土壤钾镁交互作用对烤烟化学及感官品质的影响

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...

Effect of Soil Potassium and Magnesium Interaction on Chemical and Sensory Quality of Flue-cured Tobacco in Yuxi Tobacco Area

Using Yuxi tobacco-planting soil as a research object, the effects of soil rapidly available potassium and available magnesium and their interactions on the combined quality of flue-cured tobacco were analyzed. Results showed that the average content of soil rapidly available potassium in Yuxi was 325.9 mg/kg, with a variation of 93.0 ~ 713 mg/kg, and the average content of soil available magnesium was 207.9 mg/kg, with a variation of 40.0 ~ 610 mg/kg. 85.3% of the soil rapidly available potassium in Yuxi was in the range of rich and suitable, and 14.7% was still in the range of potassium deficiency. 76.5% of soil available magnesium was in the range of rich and suitable, and 23.5% was in the range of Mg deficiency. With the increase of soil rapidly available potassium content, potassium in flue-cured tobacco showed a trend of increasing and then decreasing, and magnesium in flue-cured tobacco showed an increasing trend, and there was a significant positive correlation between soil rapidly available potassium and magnesium in tobacco (P < 0.05), while nicotine and total nitrogen showed a trend of decreasing and then increasing, and total sugar and reducing sugar, sugar-nicotine ratio and nitrogen-nicotine ratio showed a decreasing trend. With the increase of soil Mg content, the trend of decreasing potassium and increasing Mg, the trend of negative correlation between soil available magnesium and potassium (P < 0.01) and positive correlation between soil available magnesium and Mg (P < 0.01), the trend of increasing and then decreasing nicotine, the trend of increasing total N, and the trend of decreasing and then increasing total and reducing sugars, sugars-nicotine ratio and nitrogen-nicotine ratio. The increase of soil rapidly available and available magnesium significantly (P < 0.05) enhanced the sweetness and aroma of flue-cured tobacco leaves, respectively. The interaction of soil potassium and magnesium had significant (P < 0.05) effects on total sugar, reducing sugars and nitrogen-nicotine ratio of flue-cured tobacco leaves. Therefore, potassium fertilization should be increased on the basis of proper magnesium fertilization in Yuxi flue-cured tobacco planting, and attention should also be paid to the effects of other fertilizers such as nitrogen fertilization on potassium and magnesium in flue-cured tobacco, so as to further improve the quality of local flue-cured tobacco.