Performance of direct-seeded rice under various dates of sowing and irrigation regimes in semi-arid region of India

Rice (Oryza sativa L.) is the most important staple food crop in the southern region of Asia, and Indian subcontinent being one of the major producers. Production of conventional transplanted rice requires a large amount of irrigation water, labor, and energy. The scarcity of irrigation water has encouraged farmers to adopt an alternative rice production system, i.e. the direct-seeded rice (DSR), which is proposed to be farmers’ friendly with a potential to save water. Our study reports the performance of DSR with respect to yield and water expense efficiency based on different irrigation regimes and dates of sowing. A field experiment was conducted in the semi-arid region of northern India during the rainy season of 2011 with two treatment combinations (dates of sowing: 15th May and 5th June and three irrigation regimes: irrigation scheduled at irrigation water-to-cumulative potential evapotranspiration; IW/CPE ratio of 1.0, 1.5 and 2.0) in a completely randomized design. We found statistically higher water expense efficiency of DSR sown on 5th June as compared to DSR sown on 15th May without any significant differences in growth and yield. A significant yield difference between DSR grown with irrigation regimes of IW/CPE 1.0 and 1.5 and DSR grown with irrigation regimes of IW/CPE ratio 2.0 were observed. The DSR grown with irrigation regimes of IW/CPE ratio of 1.5 resulted in significantly higher water expense efficiency than the one with IW/CPE ratio of 2.0. Obtaining a higher yield of DSR under scarce irrigation water might be a trade-off between optimum water use and maximum yield avoiding excess ground water exploitation in sub-tropical semi-arid regions of India. Our study suggests that sowing time and irrigation regimes are two important aspects of “rice production” to attain “win–win” solution. Thus, strategic and judicial use of irrigation water with management of sowing time could potentially escalate the rice production in water scarce regions of India.