Prospects of biodrainage to mitigate problems of waterlogging and soil salinity in context of India - A review

Major parts of agricultural lands in arid and semi-arid regions of India are affected by soil salinity and waterlogging in canal command area and outside. Waterlogging is caused by a rising water table and poor drainage conditions.  Stress due to waterlogging and salinity are serious to plants in all stages from seed germination to active growth and maturity. Unmanaged affected agricultural lands turn into low productive marshlands in the long run. Physical provision of surface or sub-surface drainage structures can rescue in such a situation. Yet, high skill and investment are required in the installation and maintenance of such structures. Alternatively, biodrainage method has been evolved as an effective method recently world over. In biodrainage, plants are raised over a larger area, which can transpire and remove an enormous amount of water from the soil. Plants having adequate adaptive traits and tolerance mechanisms are desirable to mitigate waterlogging and salinity. Biodrainage is suitable in rainfed and irrigated conditions. Planting of right plant species in optimum population and geometry decides the efficiency of biodrainage. Further, combining biodrainage with the conventional drainage can improve land and water productivity. Eucalyptus is the most suitable tree species for biodrainage as it has well performed in versatile environments. It possesses appreciable tolerance to salinity, sodicity and waterlogged conditions of the soil.  Fast-growing with a straight trunk, deep rooting ability, low shading effect and high transpiration capacity are promising characteristics of this tree.  Prominent woody species like Acacia nilotica, Dalbergia sissoo, Hardwickia binata can also be grown for high profit.