Quiz by instructor and participation in lab activities. Soil is composed of mineral matter that has been broken down by chemical, physical and biological action to the point where it can, when contained with decayed plant and animal life, called support life 2. The more living organisms there are in the soil, the more productive the soil is likely to be. This increased productivity is due to larger amounts of nutrients being made available by the decomposition of organic matter by the soil organisms. Soil also contains a variable percentage of water and air.
Parent material is the unweathered material from which a soil is formed.
Soils resemble the parent material from which they come. The nature of the parent material will have a strong effect on the properties of young soils and will exert lesser influence on older soils. Properties of the parent material that exert an influence on soil development include texture, mineral composition and degree of layering. The chemical and mineral composition of a soil often not only determine the effectiveness of the weathering forces, but in some instances partially controls the natural vegetation. Soil acidity encourages mineral decomposition and the overall development of the soil profile.