Delineation of soil water balance in wheat-dry direct seeded rice system under conventional and zero-till conditions in semi-arid tropics

Effective establishment methods for rice-wheat sequence including intervening periods in semi-arid tropics of India for practising sustainable agriculture is urgently required, moreover delineating soil water balance components in different establishment methods also required. Keeping this in mind, field experiments investigating the effects of different tillage methods on the soil water balance of irrigated wheat (Triticum aestivum)-rice (Oryza sativa) cropping sequence (RWCS) were conducted during 2012–2014 in Punjab, India, on a sandy loam soil. The irrigation water productivity (WPI) of wheat-rice cropping system ranged from 0.56–0.74 kg m ^-3 in 2012–13 compared to 0.45–0.54 kg m ^-3 during 2013–14. During intervening period after wheat evaporation losses pragmatic to be higher in the zero tilled wheat (ZTW) plots. Among the pure tillage systems, conventionally tilled wheat followed by conventionally tilled direct seeded rice (CTW-DSRCT) plots had highest irrigation water productivities (32.1 and 20 percent) during 2012 and 2014 than zero tilled wheat followed by zero tilled direct seeded rice (ZTW-DSRZT) plots while among the mixed tillage systems zero tilled wheat followed by conventionally tilled direct seeded rice (ZTW-DSRCT) plots had higher water productivities (17.8 and 4.4 percent) than the conventionally tilled wheat followed by zero tilled direct seeded rice (CTW-DSRZT) plots during 2012–2014. Among the different tillage scenarios, irrigation (WPI), total input (WPI+R) and evapotranspiration (WPET) based water productivity followed the order CTW-DSRCT > ZTW-DSRCT > CTW-DSRZT > ZTW-DSRZT.