50-Modelling use of Saline and Sodic Groundwater for Crop Production

Abstract

Competing demands from domestic, industrial and recreational sectors are likely to snatch a large portion of the good quality water from agricultural sector. With its own escalating demand, the agricultural sector has to look for other avenues to meet a part of its requirement. Saline and sodic ground waters are some of such avenues, which could be easily exploited. Although field evidences have been generated over the last 35 years to demonstrate the potential of poor quality ground waters for crop production, yet questions are raised time and again on the Long-term consequences of such use. To settle this issue, modeling has become a handy tool. This paper reviews four such models, which have been used in the recent past for modeling assessment of water quality, develop crop production functions, model field processes and predict anticipated crop yields. These models are SALT (To assess crop production functions as a function of water quality), Salty Water Assessment and Management (SWAM), Simulation of water flow, solute transport and plant growth in Soil-Water-Atmosphere-Plant environment (SWAP) and UNSATCHEM (simulates the one- dimensional saturated water flow, heat transfer, carbon dioxide production and transport, and multi-component solute transport). The potential of these models has been shown by reviewing the work done in India and by briefly highlighting the situations, which could be simulated by these models. It has been shown that together these four models provide a sound framework to simulate most processes and field situations likely to be encountered under the use of saline/sodic waters for crop production. Besides concluding that most general recommendation emerging from field studies are sound. Besides, their long-term implications are also discussed.