Bioremediation of waterlogging and soil salinity for sustainability of agriculture: Problems and prospects
Dr. Sanmay Kumar Patra, Madhurima Banik
The sustainability of agriculture is adversely affected by twin menace of waterlogging and soil salinity. The adoption of conventional surface and sub-surface drainage technology to address the waterlogging and salinity problems is costlier propositions and causes ecological degradation. Biodrainage using tree species of high consumptive use of water is an alternative promising technology to remediate the saline and waterlogged lands. It is cost-effective and environment-friendly and eliminates the drainage effluent hazards. It simultaneously produces higher economic returns through fodder, fuel wood or fibre harvested and sequesters carbon in biomass. It is specially suited in areas of sweet groundwater availability and humid regions where the initial soil salinity is low. Despite several advantages, biodrainage technology has some limitations and shortcomings as well. It needs extra land for tree plantation. The adaptation of high biodrainers like Eucalyptus in receded groundwater table areas will augment environmental disaster. The harvesting of salts from saline soil by plantations in semi-arid and arid regions is contradictory; rather it accelerates the salt accumulation in plantation strips and increases root zone salinity over the long-term. However, the feasibility of biodrainage species for land reclamation in different sets of soil and climatic conditions needs to be explored experimentally. In the present state of knowledge, biodrainage as partial substitution or in conjunction with conventional drainage could be the viable option in saline waterlogged areas for increasing the crop productivity.