Greening Salty and Waterlogged Lands Through Agroforestry Systems for Livelihood Security and Better Environment

Abstract

Nearly, one billion hectares of arid and semi-arid areas of the world are salt-affected and remain barren due to salinity or water scarcity. In India, about 6.75 Mha lands are either sodic or saline in nature and 6.41 Mha land is degraded due to waterlogging. These lands constrain plant growth owing to the osmotic effects of salt, poor physical conditions leading to poor aeration, nutrition imbalances, and toxicities. To meet the requirements of food and other agricultural commodities for the burgeoning population is a big challenge for agricultural community. With the increasing demand for good quality land and water for urbanization and development projects, in future, agriculture will be pushed more and more to the marginal lands and use of poor quality water for irrigation is inevitable. With use of appropriate planting techniques and salt-tolerant species, the salt-affected lands can be brought under viable vegetation cover. Further, in most of the arid and semi-arid regions the groundwater aquifers are saline. Usually, cultivation of conventional arable crops with saline irrigation has not been sustainable. Concerted research efforts have shown that by applying appropriate planting and other management techniques (e.g., sub-surface planting and furrow irrigation), the degraded salty lands (including calcareous) can be put to alternative uses (agroforestry) and salt-tolerant forest and fruit trees, forage grasses, medicinal and aromatic, and other high value crops can be equally remunerative. Such uses have additional environmental benefits including carbon sequestration and biological reclamation. Agroforestry is not only a necessity for increasing tree cover and hence decreasing pressure on natural forests, but also a most desired land use especially for reclaiming and rehabilitating the degraded lands. In developing countries like India, there seems to be little scope for bringing the fertile lands under forestry cover. It may be emphasized here that we can bring unproductive wastelands and waterlogged areas under forest cover and take agroforestry tree plantation on nonforest community and farmlands. The long-term studies conducted show that salt-affected and waterlogged areas and saline waters can be utilized satisfactorily in raising forest and fruit tree species with improved techniques, forage grasses, conventional and nonconventional crops, oil-yielding crops, aromatic and medicinal plants of high economic value, petro-crops, and flower-yielding plants. Opportunities for raising salt-tolerant crops and alternate land uses through agroforestry on salty and waterlogged areas, especially in arid and semi-arid regions have been discussed in this chapter.