Drainage, soil water storage, buffering and filtering

Drainage is the natural or artificial removal of water from the land either through surface drainage, subsurface drainage or a combination of both. The practice of land drainage may be beneficial if soil water conditions create a need for drainage due to shallow groundwater or soils with low permeability. In agricultural settings, the natural, internal drainage of most soils is adequate to prevent waterlogging, but many soils require artificial drainage to improve field trafficability for field operations and to protect growing crops from excess soil water conditions. Drainage helps to provide an optimal balance of water and air in the soil necessary for plant growth, as well as the diverse function and services of soil-dwelling organisms.