Saving of water and labor in a rice-wheat system with no-tillage and direct seeding technologies

Conventional tillage and crop establishment methods such as puddled transplanting in the rice-wheat (Oryza sativa L.-Ttiticum aestivivum L.) system in the Indo-Gangetic Plains (IGP) require a large amount of water and labor, both of which are increasingly becoming scarce and expensive. We attempted to evaluate alternatives that would require smaller amounts of these two inputs. A field experiment was conducted in the IGP for 2 yr to evaluate various tillage and crop establishment systems for their efficiency in labor, water, and energy use and economic profitability. The yields of rice in the conventional puddled transplanting and direct-seeding on puddled or nonpuddled (no-tillage) flat bed systems were equal. Yields of wheat following either the puddled-transplanted or no-tillage direct-seeded rice were also equal. Normally, puddled transplanting required 35 to 40% more irrigation water than no-tillage direct-seeded rice. Compared with conventional puddled transplanting, direct seeding of rice on raised beds had a 13 to 23% savings of irrigation water, but with an associated yield loss of 14 to 25%. Nevertheless, water use efficiency (WUE) in the rice-wheat system was higher with direct-seeded rice (0.45 g L-1) than with transplanted rice (0.37-0.43 g L-1). In Year 1, no-tillage rice-wheat had a higher net return than the conventional system, whereas in Year 2 the net returns were equal. The study showed that the conventional practice of puddled transplanting could be replaced with no-tillage-based crop establishment methods to save water and labor. However, the occurrence and distribution of rainfall during the cropping season had considerable influence on the savings in irrigation water.