The study of soils is called pedology , which investigates the appearance, the mode of formation, the distribution, and classification of soils. Basically, all life depends on soil which is perhaps the most undervalued of all natural resources. Soil is developed from parent material , which is defined as all forms of mineral matter that are suitable for transformation into soil. The parent material for soil can be bedrock and regolith, as well as transported sediment material. Black or dark brown soils have a lot of organics, and are therefore very fertile.
Red soils are very rich in iron compounds.
A white layer in the soil indicates the presence of salt , perhaps due to evaporation, as well as the presence of sand . Soil texture refers to the mineral particles that comprise the soil, which are divided into sand, silts, and clay-sized particles . A texture triangle can be used to classify a soil into a soil texture class based on the percentages of sand, silt, and clay. This classification is important because texture will help determine the agricultural potential of a soil in a region. For example, sandy soils have poor potential, while loamy soils have the greatest potential.