Maize-based intercropping systems achieve higher productivity and profitability with lesser environmental footprint in a water-scarce region of northwest China

Global agriculture is facing multiple challenges to meet the food demands, optimize resource utilization, and mitigate the climate change. A field study, combined with the life cycle assessment (LCA), was conducted to select the effective and sustainable cropping systems in northwestern China. The study compared four maize-based intercropping and corresponding monoculture systems on crop yield, evapotranspiration (ET), water use efficiency (WUE), profitability, and carbon footprint (CF). Maize/wheat intercropping had the highest energy yield (532.5 GJ/ha, on average) and maize equivalent energy yield (MEEY) (522.3 G/ha, on average), followed by those from the maize/rape intercropping system, and the lowest by the sole potato system. The WUE of maize equivalent energy yield (WUEMEEY) was the highest (1.06 GJ ha(-1) mm(-1)) for sole rape system, followed by those for the maize/wheat and maize/rape intercropping systems. Maize/potato intercropping had the highest benefit: cost ratio at 3.30, followed by those for the maize/wheat intercropping (2.58), sole potato (2.57), and maize/rape intercropping (2.53). Lower CF and higher net ecosystem economic budget (NEEB) were observed in maize-based intercropping systems. The maize/wheat intercropping system had the lowest CF per maize equivalent energy yield (CFm) (10.7 kg CO2-eq GJ(-1) year(-1)), and the maize/potato intercropping system had the lowest CF per unit economic output (CFe) (0.14 kg CO2-eq US$(-1) year(-1)), and the highest NEEB (7,352.8 US$/ha). The data presented indicate that maize-based intercropping system may be a viable practice for the synthesized goals of higher productivity and profitability while lesser environmental footprint in a water-scarce region of northwest China.