一、土壤是由那些物质组成的表面上看来,土壤组成很简单,不过是一些大小不同的土块和土粒。事实上却不然,土壤是一种相当复杂的物质。土壤里的物质可以概括为三个部分:固体部分、液体部分和气体部分。固体部分中有粗细不同的矿物质颗粒和分解程度不等的有机质,还有我们 First, the soil is composed of those substances On the surface, the soil composition is very simple, but some different sizes of soil and soil particles. In fact, otherwise, the soil is a rather complicated substance. Soil material can be summarized into three parts: the solid part, the liquid part and the gas part. Solid part of the different thickness of mineral particles and decomposition of varying degrees of organic matter, and we