The intensification of irrigated agriculture is required for attaining food security. It could result, however, in water resources problems of waterlogging and secondary salinization. To assess different management strategies in solving the problems, the current study used a simulation model SaltMod in a command area of north-west India which faced the problems of salinization and waterlogging. Following the thriving testing in the course of calibration and validation, it was used for studying various water management alternatives for the command area. The analysis of different scenarios shows that watertables in the command would persist to go up under the normal conditions. Thus, right management alternatives, for example, increased groundwater use, rice area reduction, and reduced canal water use are recommended. The ideal scenario revealed that small changes of 3–6% in input values would contain the problems of the study region.
The water and soil resources are limited and they experience gradual degradation (Chitsaz and Azarnivand, 2017; Singh, 2018a, 2016a). Besides, farm production requires to be increased using these limited resources for feeding the burgeoning global population (Xie et al., 2018; Lomba et al., 2017; Li and Zhang, 2015; Singh, 2018b, 2014; Liu et al., 2016; Davijani et al., 2016). The intensification of irrigated agriculture is required for realizing food security (Das et al., 2015; Singh et al., 2016) in dry regions given that normal rainfall in these areas is highly unreliable (Herrmann et al., 2016; Adhikari et al., 2017; Postel, 1999). This intensification, however, could result in water resources problems of rising watertables and secondary salinization (Tilman et al., 2002; Houk et al., 2006; Singh, 2012, 2017a,b). Abbas et al. (2013) stated that soil salinization is growing globally at an average annual rate of over 2 million ha. In recent times, the Food and Agriculture Organization FAO reported that more than 19 percent of the total irrigated territory is suffered by salinization (FAO, 2016).
It is clear from evaluating the results that SaltMod appears to be a helpful model for the simulation of watertable depths and salinities in agricultural areas. It is capable of appraising the upcoming water and salt balances through a range of interventions. The watertables in the command area would persist to go up in the coming years in the existing conditions. Therefore, assured crop cultivation in the study region could not be continued under the present cropping pattern, discharge/recharge, and agro-hydro-meteorological settings. Under the optimal conditions, a decreased rice area against non-rice crops is recommended, since it could trim down percolation significantly. Apart from rice area reduction, enlarged use of groundwater and reduced canal water use are also recommended. Groundwater withdrawals can be augmented by putting in additional tubewells at fresh sites and encouraging stakeholders/farmers to utilize poor quality groundwater in conjunction with limited higher-quality canal water for irrigation purposes. The optimal scenario revealed that small changes of 3–6% in input values would contain the hydrological problems of the study region. The discussed management alternatives, if put into practice, will help significantly to lessen the groundwater table rise and secondary salinization of agricultural lands.