Designing an ecologically sustainable and resource-efficient rice-wheat system in the Western Indo-Gangetic Plains of India: Integrating practices of pressurized irrigation, tillage and residue management

Intensive tillage and on-field residue burning have gained significant traction in South Asia's rice-wheat system (RWS), often with little attention for their economic, soil health, and environmental impacts. This study seeks to identify the resource smart agri-food systems while promoting conservational tillage and residue management practices with pressurized (drip/mini-sprinkler) irrigation systems. A two-years field experiment was executed in RWS to assess the crop establishment [(puddled transplanted rice (PTR) and direct-seeded rice (DSR); conventional tillage wheat (CTW) and zero tillage wheat (ZTW)], conservation tillage (reduced/zero) and residue management (with and without mulching) practices with surface, drip, and mini-sprinkler (MSIS) irrigation techniques. The results indicated that the greater availability of soil moisture in PTR led to notable improvements in both morphological (DMA: 10.8%) and physiological traits (RWC: 5%; Pn: 7.9%, gS: 3.8% and E: 7.4%), ultimately resulting in enhanced yield components [(filled grains per panicle (17%) and 1000-grain weight (8%)] and an overall yield increase of 11% compared to DSR. Furthermore, the yield penalty of 10% associated with DSR was compensated by a 14% enhancement in crop performance in ZTW. The favorable alterations in soil moisture conditions and the more effective utilization of available resources in the pressurized irrigation residue mulched ZTW system (DRIP/MSIS-ZTW+RM) facilitated superior crop growth and enhanced yield metrics, achieving a 17% increase in wheat yields and a 53% improvement in irrigation water use efficiency relative to CTW. Residue mulching increased wheat yield by 7%, with gains of 6.3% in SIS, 7.1% in MSIS, and 7.7% in DRIP-irrigated ZTW. The AquaCrop model performance was deemed adequate to validate and simulate rice and wheat yield and water footprint (WF) for various treatments applied to both the crops. Notably, the DRIP-DSR treatment recorded a 14.2% lower blue WF in comparison to PTR, and a 42.7% reduction when compared to SIS-DSR. For wheat, the DRIP-ZTW treatment demonstrated a 29.4% decrease in blue WF compared to CTW, with residue mulch leading to an additional 32.8% reduction. On average, retaining surface residue as mulch (+RM) resulted in a 10.5% lower blue WF than without mulch (–RM). Transitioning from conventional RWS to a drip-irrigated DSR-ZTW system, complemented by rice residue mulching (DRIP-DSR/ZTW+RM), offers a resource-efficient sustainable alternative for ecological sustainability and food security in the western Indo-Gangetic Plains (IGP) and similar regions.