7. Delineation and Characterisation of Salt-affected and Waterlogged Soils in Ignp (phase I), Rajasthan (cssri)

The Thar Desert occupies about two-third part in the State of Rajasthan. Traditionally, agriculture in this region depends on the scanty rainfall. Irrigation was introduced in ths area by commissioning Indira Gandh Nahar Pariyojona (IGNP). The total irrigation potential is estimated as 13.87 lakh hectares. Canal irrigation has brought a significant change in the cropping pattern. The traditional rainfed subsistence crops have been replaced by cash crops. On an average annual area sown has increased by 200% after introduction of canal irrigation. As a result of canal irrigation, most part of the Ganganagar district experienced a significant increase in crop production. However, irrigation has also. brought problems such as waterlogging and soil salinity, which not only degraded the good irrigated agricultural lands but also devastated the village hamlets. As a consequence, most part of the areas around the main canal where water delivery is comparatively high experienced high water tables and water stagnation particularly in the low-lying flats and depressions. Canal seepage, surface irrigation practices, sandy soil texture and the presence of hard impermeable layer at shallow depth are found to be among the several factors responsible for the development of water ponding, high water table and secondary salinization in the command area.