曲靖烤烟镁含量特征及其影响因素

摘要

为研究曲靖烤烟镁含量特征及其影响因素,在曲靖烟区采集烤烟样品3506个,采用决策树分析、回归分析等方法研究了曲靖烤烟镁含量特征及其主要影响因素.结果表明:曲靖烟区烤烟镁含量平均为4.10 g/kg,且变幅较大(0.36~17.70 g/kg),有46.36%面积的烟叶镁含量<4 g/kg,镁含量在县域间差异达极显著水平,海拔高度、土壤类型、质地及有机质、速效钾、有效镁、有效钙含量均影响烤烟镁含量.烤烟镁含量与海拔高度呈良好的线性关系(R2=0.720,P=0.000),随海拔增加,烤烟镁含量表现为下降的趋势.土壤质地黏性增加,烤烟镁含量呈下降的趋势;烤烟镁含量在不同土壤类型间差异达极显著水平,最高的是紫色土(4.98 g/kg),最低的是红壤(3.82 g/kg);随土壤有机质含量增加,烤烟镁含量表现为逐渐下降的趋势;随土壤有效镁和速效钾含量增加,烤烟镁含量表现为逐渐增加的趋势;随土壤有效钙含量增加,烤烟镁含量呈先升高后下降的趋势,土壤有效钙含量2000 mg/kg左右时,烤烟镁含量达峰值;随着土壤钙镁比和钾镁比升高,烤烟镁含量呈减速下降的趋势.%3506 samples of flue-cured tobacco leaves were collected from Qujing of Yunan Province and their Mg contents were analyzed, then decision tree analysis and regression analysis were used to study the influential factors. The results showed that Mg contents ranged from 0.36 g/kg to 17.70 g/kg with a mean of 4.10 g/kg in flue-cured tobacco leaves, and Mg contents were lower than 4.00 g/kg in 46.36% of the samples. Altitude, soil type, texture, organic matter, available potassium, available magnesium, and available calcium affected Mg content of flue-cured tobacco. Mg content of flue-cured tobacco decreased with the increase of altitude and the fining of soil texture. It was significant difference in different soil types, the highest (4.98 g/kg) in purple soil and the lowest in red soil (3.82 g/kg). Mg content decreased with the increase of SOM, gradually increased with the increase of soil available Mg and available K, and increased first and then decreased with the increase of soil available Ca. Mg content reached the highest while soil available Ca was about 2 g/kg. And Mg content decreased with the increase of soil Ca/Mg an K/Mg ratios.