Germplasm and management strategies for enhancing productivity of salt-affected areas

Abstract

The productivity of salt-affected coastal and inland areas is seriously hindered by salt stress, and disproportionately affects poor farmers. Our work involves identification of rice and non-rice crops and varieties tolerant to salt stress; unraveling the underlying mechanisms of tolerance, transferring tolerance into suitable varieties, and evaluating them in partnership with farmers. Conventional and modern breeding strategies are used including the development and use of molecular markers, to greatly speed the breeding process. Through a network of germplasm exchange, breeding lines were selected by seven NARES in three river basins, and numerous salt-tolerant lines were either released as varieties for commercial use or promoted for release as in India, Bangladesh, and Vietnam. Affordable integrated crop, nutrient, and other natural resources management practices, including soil sodicity/salinity mitigation strategies, were developed in association with salt-tolerant material. These strategies include proper seedling nursery management, integrated use of organic, inorganic, and biofertilizers, water management, and the use of cheap amendments such as 'pressmud,' are being validated and out-scaled through farmer participatory approaches. Use of tolerant varieties also helped reduce the amount of gypsum required to reclaim sodic soils to only 0.25 of the recommended levels. Effective cropping patterns were developed through adjusting the cropping calendar, which became feasible with the availability of short-maturing salt-tolerant varieties. Through partnership with ICRISAT and ICBA, new non-rice crops were introduced for the dry season where freshwater resources are scarce, and in areas where salinity is too high, rice-shrimp/fish systems were evaluated. These interventions demonstrated enormous potential for enhancing land and water productivity and farmers’ income in salt-affected areas.