1.分类依据。soil types are classified based on the particle size.hardness.moisture content.and other physical and chemical properties of the soil.This classification helps to better understand the characteristics of the soil and determines its suitable applications。2.特性的差异。1.第一类土通常含有较多的砾石和碎石，颗粒较粗，具有较好的排水性和通气性。这类土壤物理结构良好，养分含量较高，质地坚硬，因此适合用于建筑和道路建设等工程。