On-farm water management in saline groundwater area under scarce canal water supply condition in the Northwest India

The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers' fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to help develop some guidelines to the farming community. Water management alternatives at the field level were suggested to increase the yield and to maintain soil salinity below threshold level. The application of frequent irrigation in precisely leveled field would help in achieving 10% higher yield even when saline groundwater of 11 dS/m is used for irrigation. (C)2008 Elsevier B.V. All rights reserved.