Author(s):

Ramesh Chand Bana, Vinay Kumar, Dr. Amar Singh and Girdhari Lal Jakhar

Abstract: Two major approaches to improving and sustaining high agricultural productivity in saline/alkali environment involves (i) modifying the environment to suit the available plants and (ii) modifying the plants to suit the existing environment. They could be used in substitutional as also in inclusive mode to make possible the productive utilization of poor quality water without compromising the sustainability of the production resource based at different levels of management units. Some of these issues, as related to the use of marginal quality water both at field and irrigation system levels are highlighted. An overview of the results of field studies encompassing areas with low to moderate monsoonal rainfall (400-600 mm) and underlain by saline/alkali water, supplemented with deficit canal water supplies, sufficient only to meet 40-50 percent of irrigation requirements shows that there are good possibilities of achieving reasonably high water productivity on sustainable basis by appropriate technological interventions. The important interventions include; in-situ conservation of rainwater in precisely leveled fields, blending saline/alkali and fresh waters to keep the resultant salinity below threshold or their amelioration, if residual sodium carbonate cannot be brought down to acceptable levels by dilution blending or cyclic application and scheduling irrigation with salty water at less salt sensitive stages. In high water table areas, provision of sub-surface drainage facilitates the use of higher salinity water, reducing the overall irrigation requirement. At higher levels of irrigation system, water productivity in saline environment has been found to increase by reallocation of water to higher value crops with limited irrigation requirement, spatial reallocation and transfer of water adopting policies that favour development of water markets and reducing mineralization of fresh water by minimizing application and conveyance losses that find path to saline aquifers. In spite of the technological advances that mitigate salinity damages and the likely economic advantages, there is always a need to exercise caution while practicing irrigation with salty water for maintaining sustained productivity.

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