What Is Soil Made of?

Soils are mostly made up of pulverized rocks that contain different mineral compounds.

Organic compounds, from the remains of plans and animals, make up the rest of the soil.

Plants use this mixture of organic and inorganic materials to nourish themselves.

Different soils have similar ingredients.

However, these ingredients appear in different proportions.

These differences in proportion lead to differences in the types of soil.

Soils are categorized according to how much sand, lime, clay or vegetable matter they have.

Sandy loams are 80 to 90 percent side, while sandy soils have more than 90 percent sand.

Marly soils have from 5 to 20 percent lime, while chalky, or calcareous, soils have more than 20 percent chalk or lime.

Loamy soils are 20 to 30 percent clay, clay loams are between 30 and 50 percent clay, and clay soils have more than 50 percent clay.

Vegetable soils, or peaty soils, have more than five percent humus or decayed vegetable matter.

Every known soil falls into one of these categories or into an intermediate category between two different soil types.