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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3 506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(R~2=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2 000 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。
In order to study the characteristics and influencing factors of magnesium content in flue-cured tobacco in Qujing, 3 506 flue-cured tobacco samples were collected in Qujing tobacco-growing areas. The characteristics of magnesium in Qujing flue-cured tobacco and its main influential factors were studied by means of decision tree analysis and regression analysis. The results showed that the average magnesium content in flue-cured tobacco in Qujing tobacco area was 4.10 g / kg, and the variation range was relatively large (0.36 ~ 17.70 g / kg). The content of magnesium in the tobacco with 46.36% area was less than 4 g / kg, Reaching extremely significant level, altitude, soil type, texture and organic matter, available potassium, available magnesium and available calcium all affected the magnesium content in flue-cured tobacco. Flue-cured tobacco magnesium content and altitude showed a good linear relationship (R ~ 2 = 0.720, P = 0.000), with the altitude increased, the flue-cured tobacco magnesium content showed a downward trend. The content of magnesium in flue-cured tobacco tends to decrease with increasing soil texture viscosity. The content of magnesium in flue-cured tobacco reaches the most significant level among different soil types, the highest is purple soil (4.98 g / kg) and the lowest is red soil (3.82 g / kg) ; With the increase of soil organic matter content, the magnesium content of flue-cured tobacco tends to decline gradually. With the increase of soil available magnesium and available potassium, the magnesium content of flue-cured tobacco tends to increase gradually. With the increase of available soil calcium content, The content of Mg in flue-cured tobacco reached its peak when the effective soil calcium content was about 2 000 mg / kg. With the increase of Ca-Mg ratio and potassium-magnesium ratio, the magnesium content of flue-cured tobacco showed a downward trend.