Soil fertility refers to the ability of a soil to sustain plant growth, i.e. to provide plant habitat and result in lasting constant yields of high quality.
A fertile soil has the following properties:
It is rich in nutrients necessary for basic plant nutrition, including nitrogen, phosphorus and potassium
It contains sufficient minerals (trace elements) for plant nutrition, including boron, chlorine, cobalt, copper, iron, manganese, magnesium, molybdenum, sulphur, and zinc.
It contains soil organic matter that improves soil structure and soil moisture retention.
Soil pH is in the range 6.0 to 6.8 for most plants but some prefer acid or alkaline conditions.
Good soil structure, creating well drained soil, but some soils are wetter (as for producing rice) or drier (as for producing plants susceptible to fungi or rot, such as agave).
A range of microorganisms that support plant growth.
It often contains large amounts of topsoil.