内蒙古草原经度地带性土壤地球化学特征研究

Inner Mongolia Grassland Longitude Zonal Soil Geochemistry

摘要: 内蒙古自治区地域辽阔，相应土壤地球化学特征分异随经度地带性呈现规律性变化，本文以前人土壤普查为基础，以经度地带性规律为线索，对土壤地球化学特征进行数据整理，研究各项数据指标的经度地带性变化规律，对于内蒙古土壤的理论性研究具有重大意义。研究结果表明，内蒙古草原土壤区域辽阔，由于气候因素的影响，内蒙古草原土壤呈经度地带性分布，相对应的土壤地球化学特征也呈现出经度地带性排列：自东向西，土壤中SiO₂、Na、K、Ca、Mg等盐基以及有机质含量逐渐降低，而CaCO₃含量逐渐升高。自东向西，Sa值、Saf值、ba值、β值、μ值基本上呈现逐渐升高的趋势；粉粘比、CEC、H/F、有机质/CaCO₃则呈现出逐渐降低的趋势。自东向西，内蒙古草原土壤的淋溶强度逐渐减弱，既是化学风化作用逐渐减弱，物理风化作用逐渐增强；自东向西，内蒙古草原土壤草原化过程的强度逐渐减弱。自东向西，内蒙古草原土壤中有机质含量逐渐降低，而CaCO₃含量逐渐升高，体现了草原土壤二层性的变化规律。试验中加入了两个荒漠土壤试验点，试验结果显示出荒漠草原土壤在Sa值、Saf值、ba值、β值、μ值上，并没有明显与草原土壤相关的经度地带性排列特征，可能主要是由于在成土过程中几乎没有植物介入的原因。

Abstract: On the Inner Mongolia’s vast territory, corresponding fractionation of soil geochemistry changes regularly with longitudinal zonality. This paper, based on the past soil survey, taking longitude zonal pattern for clues, processes on soil geochemistry data collation and studies various data indexes’ longitude zonal variation, which has great significance for theoretical research in Inner Mongolia soil. The results showed that, mainly due to climatic factors, the Inner Mongolia grassland soils were distributed according to longitudinal zonality, and the corresponding soil geochemistry also showed longitude zonal arrangement: From east to west, the soil SiO₂, Na, K, Ca, Mg and other salt and organic matter content decreased, while CaCO₃ content increased. From east to west, Sa, Saf, ba, β, μ, basically showed a gradual increasing trend; powder stick ratio, CEC, H/F, organic/CaCO₃ is showing a decreasing trend. From east to west, Inner Mongolia grassland soil leaching intensity gradually weakened, both chemical weathering gradually weakened, physical weathering gradually increased; From east to west, the process of grassland in Inner Mongolia grassland soil strength waning. From east to west, Inner Mongolia grassland soil organic matter content decreased, while CaCO₃ content increased, reflecting the story of grassland soil variation. Two desert soil test points are added in the test, and test results show the value of desert grassland soils in Sa, Saf value, ba value, β value, μ value, and no significant correlation with grassland soil characteristics longitude zonal arrangement, which may be mainly due to the fact that there is almost no plants involved in the soil forming process.