Adopting plastic film mulching system in the food-energy-water-carbon nexus to the sustainable dryland agriculture

Agricultural production development and ecological environmental protection are the main challenges facing dryland agriculture in the Loess Plateau. Over the past four decades, this region has transitioned from a state of food shortage and ecological deterioration to a new phase with plentiful food supply and improved ecological environment. However, it remains unclear how this system navigates resource and environmental constraints, balancing economic growth and ecological preservation. Here we conducted integrated and systematic analysis by combining process-based biogeochemical model, statistical yearbook data, and rural social surveys with the life cycle assessment (LCA) methodology. The yield, economic benefits, carbon footprint (CF), and energy balance of maize, winter wheat, and potato within the plastic film mulching (PFM) cropping system surpassed those of conventional tillage, while the water footprint (WF) was lower. Among them, soil N2O was the primary source of direct greenhouse gas (GHG), while mineral fertilizer (40–71 % and 52−73 %) and agricultural diesel (13−18 % and 17−18 %) were the main contributors to indirect GHG and energy inputs. Moreover, the food-energy-water-carbon (FEWC) nexus of maize being harmonized during 1980–2019 (0.50–1.00), and those of winter wheat and potato being harmonized after 2000 (0.51–0.98 and 0.54–0.97, respectively). The maize also was more profitable than winter wheat and potato. The changing rates of yield, agricultural net profit (ANP), WF, and CF of major crops in the Loess Plateau exhibited consistent increase over time, albeit with regional differentiation characteristics. These results highlight that PFM system achieved high economic benefits and low environmental costs, and it contributed to establishing resource-efficient, production-effective, and eco-friendly dryland agriculture in China and the world.