Irrigation water management strategies for wheat under sodic environment

Wheat (Triticum aestivum) is a moderately salt-tolerant crop as well as susceptible to excess application of irrigation water. This requires a proper strategy when crop like wheat is grown under sodic environment. As it is evident that, sodic soils are characterized by a relatively low electrical conductivity (EC), high exchangeable sodium (Na) on exchange sites, soil pH > 8.0, low rate of infiltration, and dispersed soil. Thus, irrigation strategy for wheat in sodic soils differs from normal soils in terms of irrigation depth and irrigation frequency. An experiment to determine the suitable irrigation strategy along with methods of application namely: Surface (farmer's practice), Sprinkler (double nozzle impact sprinkler), and LEWA (Low Energy Water Application) were initiated in the year 2012 for wheat crop. Irrigation depth of 6 cm in case of surface method, and 4 cm in case of sprinkler and LEWA was applied at each irrigation event. The irrigation events based on IW/CPE ratios of 1.0, 0.8 and 0.6 through surface, sprinkler and LEWA methods were imposed. The results revealed that Sprinkler and LEWA resulted in highest wheat yield of 2.4 t/ha to 2.5 t/ha, which was 10 to 20 percent higher than the highest wheat yield recorded under surface irrigated plots by using 30 to 40 percent less water. Hence, use of sprinkling devices to irrigate wheat may not only lead to substantial saving of water as well as energy in terms of fuel used for pumping without compromising the crop yield under sodic enviroonment.