The Drainage: Impacts, Plant Growth, and Water Table Levels

Abstract Every soil has some degree of natural drainage. However, if the rates of precipitation or irrigation exceed the natural drainage rate of the soil, the high water table conditions will impair crop growth, because of a lack of oxygen in the root zone. Artificial, or tile drainage, is therefore required to remove excess soil water and to lower the water table, to maintain an optimum soil–air environment within the crop root zone. Most of the world's highly productive agricultural soils require either surface drainage or tile drainage, or a combination of both, to maintain stable crop yields. It is estimated that there are about 200 million hectares of cropland worldwide with improved drainage.