昭通市植烟土壤交换性钙镁特征分析

Characteristics of Exchangeable Calcium and Magnesium in Tobacco-growing Soil in Zhaotong City

【目的】探究昭通市植烟土壤交换性钙镁含量及分布特征,为科学施肥管理提供依据。【方法】利用GPS定位在昭通市烤烟种植区采集代表性植烟土壤样品,测定土壤交换性钙、交换性镁含量及交换性钙镁比,运用方差分析各县(区)植烟土壤交换性钙镁含量分布及差异性,相关分析土壤酸碱性和土壤肥力与交换性钙镁之间关系。【结果】昭通市植烟土壤交换性钙、镁含量丰富,平均值分别为2076.21和270.19 mg·kg^(-1),土壤钙镁比值大于10而引起的镁潜在性缺乏占比33.23%。植烟土壤交换性镁的变异性大于交换性钙,植烟土壤交换性钙镁比总体呈由北向南递增趋势。植烟土壤pH与交换性钙、交换性镁呈极显著正相关,交换性钙含量增幅大于交换性镁,植烟土壤交换性钙镁比随土壤pH增加而升高。植烟土壤有机质与交换性钙呈显著正相关,与交换性镁呈负相关,植烟土壤交换性钙镁比随有机质含量增加而升高。【结论】昭通市植烟土壤交换性钙镁含量在土壤空间的分布不均匀,存在较大变异性。植烟土壤交换性钙、交换性镁含量整体偏高,植烟土壤微酸性和有机质含量中高等级时,交换性钙镁比值低于10,土壤钙、镁离子活性强,有利于烤烟吸收利用。调节植烟土壤酸碱性,培肥土壤,适量补充叶面镁肥协调养分平衡,有利于提高烟叶质量。

【Objective】The content and distribution characteristics of exchangeable calcium and magnesium in tobacco-growing soil in Zhaotong city were studied to provide a basis for scientific fertilization management.【Method】Using GPS positioning to collect representative growing soil samples in Zhaotong City,soil exchangeable calcium,exchangeable magnesium content and exchangeable calcium-magnesium ratio was determined.Variance analysis was used to analyse the distribution and difference of exchangeable calcium and magnesium content in tobacco-growing soil of each County,and the relationship between soil acidity,soil fertility and exchangeable calcium and magnesium was analysed.【Result】The contents of exchangeable calcium and magnesium were rich in the soil samples with the average value of 2076.21 and 270.19 mg·kg^(-1),respectively;and the samples with exchangeable calcium-magnesium ratio higher than 10,which induced potential magnesium deficiency accounted for 33.23% of the total samples.The variability of exchangeable magnesium in tobacco-growing soil was higher than that of exchangeable calcium,and exchangeable calcium-magnesium ratio in tobacco-growing soil generally showed an increasing trend from North to South.The pH of tobacco-growing soil was significantly positively correlated with exchangeable calcium and exchangeable magnesium,and the increase of exchangeable calcium content was greater than that of exchangeable magnesium.The exchangeable calcium-magnesium ratio of tobacco-growing soil was increased with the increase of soil pH value.Organic matters in tobacco-growing soil were significantly positively correlated with exchangeable calcium,and negatively correlated with exchangeable magnesium.The exchangeable calcium-magnesium ratio in tobacco-growing soil was increased with the increase in organic matter content.【Conclusion】The exchangeable calcium and magnesium content of tobacco-growing soil in Zhaotong city was unevenly distributed in soil space,and there was a large variability.The content of exchangeable calcium and exchangeable magnesium in tobacco-growing soil was high.When the soil acidity and organic matter content were medium and high,exchangeable calcium-magnesium ratio was less than 10,and the soil calcium and magnesium ion activity was strong,which was beneficial to the absorption and utilization of flue-cured tobacco.It was beneficial to improve the quality of tobacco leaves by adjusting the acidity and alkalinity of tobacco-growing soil,fertilizing soil,and supplementing magnesium fertilizer to coordinate nutrient balance.