Fertility (soil)

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.