A food-energy-water-carbon nexus framework informs region-specific optimal strategies for agricultural sustainability

Agricultural sustainability is threatened by pressures from water scarcity, energy crises, escalating greenhouse gas (GHG) emissions, and diminishing farm profitability. Practices that diversify crop rotations, retain crop residues, and incorporate cover crops have been widely studied for their impacts on soil organic carbon and crop production. However, their associated usage of natural resources and economic returns have been overlooked. Here, we employed a food-energy-water-carbon (FEWC) nexus framework to assess the sustainability of crop rotations plus various management strategies across three sub-regions of New South Wales (NSW) in Australia. We found that compared with residue burning and fallowing, residue retention and cover cropping contributed to GHG abatement, but the latter consumed more energy and water per hectare. The composite sustainability scores, calculated with the FEWC framework, suggested that legume-inclusive rotations were generally more sustainable. Furthermore, in northern NSW (with existing sorghum/wheat/chickpea/wheat rotation), residue retention with cover cropping was most suitable combination, while the use of residue retention with fallow yielded greater benefits in southern NSW (with existing wheat/field pea/wheat/canola rotation). Regional disparities in climate, soil, cropping systems, and on-farm costs prompted region-specific strategies to address the unbalanced distribution among FEWC domains. Our study provides assessments for identifying feasible management practices to advance agricultural sustainability.