Effect of mini-sprinkler irrigation, tillage and residue on productivity, profitability and resource saving in rice–wheat system in western Indo-Gangetic Plains of India

Conventional rice–wheat system (RWCS) in the western Indo-Gangetic plain (IGP) of India is water and nitrogen intensive. Mini-sprinkler irrigation system (MSIS) is water and nitrogen efficient and helps in achieving higher nitrogen use efficiency (NUE). A comparative evaluation of MSIS versus surface irrigation system (SIS) was made to assess the NUE, water saving and techno-economic feasibility of the MSIS in RWCS. A four-year (2012–16) field experiment was conducted with four treatments namely, (1) SIS in puddled transplanted rice (PTR)—conventional tilled wheat (CTW) (SIS-PTR/CTW), (2) SIS in reduce tilled direct seeded rice (DSR)—zero tilled wheat (ZTW) with 100% rice residue mulch (RM) (SIS-DSR/ZTW + RM), (3) MSIS in DSR and ZTW with 100% RM (MSIS-DSR/ZTW + RM), and (4) MSIS in DSR with 1/3rd wheat residue and ZTW with 100% RM (MSIS-DSR + R/ZTW + RM). MSIS-DSR + R/ZTW + RM produced 5% lower system yield, but saved 49% of the applied irrigation water, resulting in 93% higher irrigation water productivity and 38% higher input water productivity as compared to SIS-PTR/CTW. Additionally, MSIS-DSR + R/ZTW + RM treatment recorded 38% less nitrogen use and 54% higher nitrogen use efficiency. Though the benefit cost (B:C) ratio of MSIS-DSR + R/CTW + RM is lower (1.45) compared to SIS-PTR/CTW (1.80) still it could be a feasible option in the areas having limited/scarce water for irrigation, and can bring more areas under irrigation.