基于地貌单元的安徽省耕地土壤pH空间变异及其驱动因子分析

Spatial variation and driving factors of soil pH in cultivated land of Anhui Province based on geomorphic unit

pH值是土壤重要的化学性质,是衡量土壤质量的重要指标之一.为了解安徽省耕地土壤pH空间差异,本研究从不同地貌单元视角进行pH空间异质性分析,并利用最优参数地理探测器对其驱动因子进行探析.结果显示:安徽省耕地土壤pH为4.13~9.43,均值为6.61,整体呈中性,其中,皖西大别山区、皖南山地丘陵和江淮丘陵等海拔较高区域土壤pH显著低于皖北平原和皖江平原等低海拔区域;土壤pH呈中等程度的空间变异,其空间异质性表现为平原>丘陵>山地,整体随海拔的升高而降低;土壤pH空间变异的驱动因子排序为潜在蒸散发>降水>土地利用方式>土壤岩性>土壤类型>气温>地貌类型>蒸汽压>坡度>灌溉方式>熟制,其中,潜在蒸散发对江淮丘陵、皖西大别山和皖南山地丘陵区土壤pH空间变异影响最大,降水和土地利用方式分别是皖北平原与皖江平原区土壤pH空间变异的主导因子;各因子交互作用主要表现为非线性增强和双因子增强,其中,潜在蒸散发∩降水的空间解释力最大,表明气候因子是影响安徽省耕地土壤pH空间变异的主导驱动因素.

As an important chemical property of soil,pH is one of the important indicators of soil quality.The spatial variability of soil pH in Anhui Province was analyzed against the background of different geomorphic units,in order to understand the spatial variability of soil pH in cultivated soil in Anhui Province.In addition,the drivers affecting soil pH distribution were further explored,based on the optimal parametric geographic model..The results showed that the pH value of cultivated soil in Anhui Province was between 4.1 to 9.4.the mean pH value of cultivated soil was 6.6,which was neutral as a whole.The soil pH value in the high altitude areas(eg.Dabie Mountains in western Anhui,mountains and hills in southern Anhui and Jianghuai hill)was significantly lower than that in the low altitude areas(eg.the northern Anhui plain and Wanjiang plain).The medium degree of spatial variability was shown in the soil pH value of Anhui Province,and its spatial heterogeneity was shown in the order of plain,hill,mountain.On the whole,the degree of variation decreased with the increased of altitude.The contribution order of influencing factors to the spatial variability of pH was as follows:potential evapotranspiration,precipitation,land use mode,soil lithology,soil type,air temperature,landform type,steam pressure,slope,irrigation method,ripening.Among them,compared with other driving factors,potential evapotranspiration has the greatest impact on spatial variation of soil pH in Jianghuai hills,Dabie mountains in western Anhui and hills in southern Anhui.Precipitation and land use patterns were the dominant factors of soil pH spatial variability in the northern Anhui plain and Wanjiang plain,respectively.The interaction of each factor is mainly manifested as nonlinear enhancement and dual factor enhancement,among the spatial explanatory power of potential evapotranspiration is the largest.The result indicated that climate factor was the dominant factor affecting the spatial variability of cultivated soil pH in Anhui Province.