Characteristics of soil that are defined by chemistry, such as the composition and reaction of soil constituents. Soil pH and nutrient supply are chemical properties contributing to soil fertility. The percolation of water through a soil. A well-drained soil is free of saturation and has considerable pore space filled with air. An expression of the capacity of soil to support crop production.
Fertility is based on soil physical properties, biological, and chemical properties.
Often soil fertility is defined as the capacity of soils to provide nutrients to plants. A layer of soil lying about parallel with the soil surface. Characteristics of horizons are used in soil classification or naming. The horizons of a soil are referred to collectively as a soil profile. The most common soil horizons are the A, B, E, and C horizons.