Perspectives for Bio-management of Salt-affected and Waterlogged Soils in Pakistan

Waterlogging and salinity have afflicted about 4.5 million ha of irrigated lands in Pakistan which has reduced production potential of the Indus Basin by 25 %. Over the last 40 years, Pakistan has adopted engineering, reclamation, and biological measures to rehabilitate these soils. Engineering solutions involved implementation of large-scale Salinity Control and Reclamation Projects (SCARPs) covering 8 million ha of land with an estimated cost of US$ 2 billion. Reclamation of saline soils was mainly achieved by leaching excess salts and the use of chemicals such as gypsum and acids. Despite initial success, the success of these initiatives has been limited due to several factors. Operational and maintenance cost of drainage projects proved a financial burden for the government and was discontinued. Nonavailability of subsidized gypsum and chemicals restricted the capacity of farmers to reclaim saline soils. As an alternative to engineering and reclamation solutions, Pakistan has made considerable progress in bioremediation by identifying and establishing plant species that can effectively lower groundwater tables and reclaims saline soils. The bioremediation systems also help in sequestering carbon, diminishing the effects of wind erosion, providing shade and shelter, and in enhancing the biodiversity. In order to derive the benefits of such efforts, bioremediation plantations have to be extended over relatively large areas. Therefore, it may not be an attractive proposition to individual farmers unless there are cooperative efforts. Involving the farming communities in such bioremediation programs seems promising for their economic and social well-being in countries such as Pakistan where individual land holdings are small.