铜仁市植烟土壤交换性钙镁空间分布特征及其影响因素分析

Spatial Distribution Characteristics and Influencing Factors of Exchangeable Calcium and Magnesium in Tobacco Planting Soil in Tongren City

为明确贵州省铜仁市植烟土壤中交换性钙和镁的状况,以铜仁2019年植烟耕层土壤交换性钙镁为研究对象,利用多元统计学和地统计学方法分析了土壤交换性钙镁空间变异特征及其影响因素。结果表明,铜仁植烟土壤交换性钙、镁含量整体丰富,平均值分别为1.72、0.27 g·kg^(-1),但仍有19.31%的交换性钙和27.59%地区的交换性镁含量处于低与极低水平。植烟土壤中钙镁比处于适宜范围的比例仅占29.70%,说明钙镁比失调较严重。土壤交换性镁含量总体呈现由西北向东南逐渐增加的趋势,土壤钙镁比总体呈现由中部向东南和西北逐渐减小的趋势,思南中部钙镁比处于最高值,江口南部与松桃南部钙镁比处于最低值。植烟土壤交换性钙、镁含量及其比值的空间变异是由结构性因素和随机性因素共同作用的结果。pH对交换性钙、镁空间变异的影响最大,分别能够独立解释其变量的41.6%、55.7%,且与交换性钙、镁分别呈现幂函数和三次函数关系,随着pH值升高,土壤中交换性钙和镁含量升高。综上,贵州铜仁植烟土壤空间分布不均匀、差异性较大,钙镁比失调比较严重,pH值对交换性钙、镁空间变异的影响最大,并与其呈极显著正相关。因此,铜仁烟区在指导钙镁施肥时要注意其空间差异性、做到分类指导,可以通过调控钙镁肥料施用量或含钙镁的改良剂调节土壤pH值来达到平衡土壤养分的目的。本研究可为铜仁市烟田钙镁养分管理提供科学依据。

In order to clarify the status of exchangeable calcium and magnesium in tobacco planting soil in Tongren city,Guizhou province,taking the exchangeable calcium and magnesium in tobacco planting soil of arable layer in Tongren in 2019 as the research object,the spatial variation characteristics and influencing factors of soil exchangeable calcium and magnesium were analyzed by multivariate statistics and geostatistics.The results showed that:The contents of exchangeable calcium and magnesium in tongren tobacco-planting soil were rich,with an average value of 1.72 and 0.27 g·kg^(-1),respectively.However,19.31%of soil exchangeable calcium and 27.59%of soil exchangeable magnesium were still at low and very low levels.In tobacco-growing soil,the ratio of calcium to magnesium in the appropriate range was only 29.70%,and the imbalance of ratio of calcium to magnesium was serious.The spatial variation of exchangeable calcium and magnesium contents and their ratios in tobacco-growing soils in Tongren city is the result of the combined effect of structural factors and random factors.The content of exchangeable magnesium in soil showed a trend of increasing gradually from northwest to southeast.In general,the ratio of calcium to magnesium increased gradually from the middle to southeast and northwest,with the highest ratio of calcium to magnesium in the middle of Sinan,and the lowest ratio of calcium to magnesium in the south of Jiangkou and the south of Songtao.pH had the greatest influence on the spatial variability of exchangeable calcium and magnesium,which could independently explain 41.6%and 55.7%of their variables,respectively.The relationship between pH and exchangeable calcium and magnesium showed power function and cubic function,respectively.With the increase of pH,the contents of exchangeable calcium and magnesium in soil increased.In conclusion,the spatial distribution of tobacco-growing soil in Tongren,Guizhou province is not uniform and the difference is large,and the imbalance is serious.The influence of pH on the spatial variability of exchangable calcium and magnesium is the greatest,and it shows a very significant positive correlation.Therefore,spatial differences should be paid attention to when guiding calcium and magnesium fertilization in Tongren tobacco area.In order to achieve classification guidance to different types of areas,soil nutrients can be balanced by regulating the application amount of calcium and magnesium fertilizer or regulating soil pH value with calcium and magnesium amendments.This study provides a scientific basis for the management of calcium and magnesium nutrients in tobacco fields in Tongren city.