Key Concepts About Soil
■ The soil is an essential resource for the production and growth of plants and crops.
■ Soils are a mixture of minerals, organic matter, organisms, pore space, liquids, and gases.
■ Soils are formed over long periods of time by the action of chemical, physical, and biological factors on sedimentary, igneous, and metamorphic rocks.
■ A soil profile is a vertical section through the soil extending from the surface to the unweathered rock beneath.
■ Organic matter is a source of nutrients for plants, aids soil aggregation and structure, and provides storage for water.
■ Soil properties affecting plant growth include texture, structure, and chemistry.
■ The ability of a soil to supply important chemical nutrients or essential elements is described as soil fertility.
■ Soil texture describes the fineness or coarseness of a soil and is determined by the proportion of specific soil particles: sand, silt, or clay.
■ Organic and inorganic fertilizers are used to supply nutrients to plants.
■ Erosion is the accelerated loss of soil through the action of wind or water. Conservation tillage and permanent vegetative covers can minimize erosion.