Experimental Evaluation of Irrigation Methods for Yield, Water Productivity, and Economics of Paddy-Wheat Cropping System under Conservation Agriculture

Irrigation methods have critical role in increasing the water productivity and crop production under paddy-wheat cropping systems. An experiment was carried out at Ludhiana, Punjab, India, in a randomized block design with eight treatments on drip and flood irrigation systems under conventional and conservation agricultural practices. Under conservation agriculture practice, drip irrigation had six treatments with different combinations of dripline spacing × emitter spacing × dripline depth as 675 × 300 × 0 mm (T1), 450 × 400 × 0 mm (T2), 675 × 300 × 150 mm (T3), 450 × 400 × 150 mm (T4), 675 × 300 × 200 mm (T5), 450 × 400 × 200 mm (T6). The treatments on conventional flood irrigation method included crop cultivation under farmer’s practice (T7) and under conservation agriculture practice (T8). The treatment T4 recorded significantly higher grain yield of wheat (6.522 t.ha-1) and paddy (8.178 t.ha-1) and water productivity (3.73, 1.20 kg.m-3, respectively. In the root zone of both wheat and paddy crops, the drip irrigation systems recorded lowest soil moisture variation within 0-450 mm soil depth under treatment T4 (4.33% to 9.77%), while it was highest under T7 (10.38% to 40.41%). The treatment T4 also showed water saving of 55.3% over the conventional flood irrigation method under paddy-wheat cropping system. In economic terms, the treatment T4 performed better with a benefit-cost ratio of 3.15 under the condition that 95% subsidy is availed on cost of drip irrigation system.