Water-energy nexus and GHG emissions of cropping systems under varying field management practices in arid India

Abstract

Agricultural systems involve interdependencies among water, energy, food, and the environment. Understanding these linkages is crucial for developing resource-efficient systems and reducing greenhouse gas (GHG) emissions to achieve sustainability. This study evaluated energy input-output analysis and GHG emissions, and assessed the interconnections among water, energy, and GHG emissions using a nexus approach of three cropping systems [cluster bean–wheat (CB-W), cluster bean–Indian mustard (CB-IM), cluster bean–isabgol (CB-IG)]under different field management practices in arid region of India. Field management practices included two tillage types [conventional (CT), deep tillage (DT)] and three farmyard manure (FYM) application rates (0, 5, 10 Mg ha⁻¹). A cradle-to-farm gate life cycle assessment was used to estimate energy use and GHG emissions. Non-renewable inputs such as electricity, fertilizers, and diesel accounted for over 80% of total energy use, with nitrogen fertilizer, diesel, and electricity being the main sources of GHG emissions. GHG emissions were highly correlated with energy use (r² = 0.93). Diversified systems (CB-IM, CB-IG) reduced groundwater irrigation, energy use, and GHG emissions by 27.9–37.2%, 22.9–37.4%, and 20.0–46.0%, respectively, compared to the traditional CB-W system. Field management practices influenced agro-economic performance, energy efficiency, and GHG emissions. DT and FYM improved water and energy productivities. The water-energy-food-GHG nexus scores were higher for CB-IG (0.773) and CB-IM (0.507) than for CB –W (0.182), with CB-IG under DT and FYM (10 Mg ha⁻¹) achieved the highest score (0.854). These results suggest that integrating suitable field management practices (e.g. deep tillage and FYM application) with diversified cropping system can enhance sustainability by reducing water and energy use and lowering environmental impacts. This approach reduces water and energy consumption while aligning with long-term environmental and economic goals, offering valuable insights for improving agricultural management in other resource-limited regions.