贵州铜仁市植烟土壤pH特征及其酸化驱动因子分析

Analysis of pH and Acidification-Inducing Factors of the Tobacco-Planting Soil in Tongren City,Guizhou Province

采用GPS定位技术,对贵州省铜仁市基本烟田进行土壤取样,研究了区域植烟土壤pH总体特征、空间变异特征及其酸化驱动因子.结果表明:铜仁市植烟土壤pH值变幅为4.17~8.29,均值为6.00,单从均值看属于适宜水平,但从样本分布情况来看,仅有34.16%的植烟土壤pH处于适宜水平,42.08%的植烟土壤pH处于低或者极低水平,铜仁市植烟土壤存在酸化的问题.半方差函数和空间插值的结果反映了铜仁市植烟土壤pH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.逐步回归分析结果表明:碱解氮和交换性氢是铜仁市植烟土壤的主要致酸因子,盐基饱和度、交换性钙和交换性镁是铜仁市植烟土壤酸化的控制因子,铜仁市植烟土壤pH是多个因子共同作用的结果.因此应根据土壤pH区域差异,适当增加含钙、镁物料的投入,控制氮肥的使用,以维持土壤的可持续利用.

Soil samples were collected from the basic tobacco fields in Tongren City,Guizhou Province,and GPS positioning technology was employed to study the characteristics of pH value of the tobacco-planting soil,and the spatial variation characteristics and driving factors of soil acidification.The results showed that the pH value of tobacco-planting soil in Tongren City ranged from 4.17 to 8.29 with an average of 6.00,which seemed to suggest that the local soil pH was appropriate for tobacco planting,but only 34.16%of the tobacco-planting soil had a pH at the appropriate level,and 42.08%was at a low or very low pH level.Semivariogram and spatial interpolation analyses showed that the spatial variation of pH value of tobacco-planting soil in Tongren City was caused by structural factors and random factors.Stepwise regression analysis showed that alkali hydrolyzable nitrogen and exchangeable hydrogen were the main acidogenic factors of tobacco-planting soil in Tongren City,and base saturation,exchangeable calcium and exchangeable magnesium were the control factors of acidification.The pH value of tobacco-planting soil in Tongren City was the result of the co-action of multiple factors.Therefore,it is recommended that the input of calcium and magnesium materials be increased and the use of nitrogen fertilizers be controlled according to the regional differences of soil pH so as to ensure the sustainable utilization of soil.