Optimizing tillage and fertilization practices to improve the carbon footprint and energy efficiency of wheat–maize cropping systems

To make agricultural systems sustainable in terms of their greenness and efficiency, optimizing the tillage and fertilization practices is essential. To assess the effects of tilling and fertilization practices in wheat–maize cropping systems, a three-year field experiment was designed to quantify the carbon footprint (CF) and energy efficiency of the cropping systems in the North China Plain. The study parameters included four tillage practices (no tillage (NT), conventional tillage (CT), rotary tillage (RT), and subsoiling rotary tillage (SRT)) and two fertilizer regimes (inorganic fertilizer (IF) and hybrid fertilizer with organic and inorganic components (HF)). The results indicated that the most prominent energy inputs and greenhouse gas (GHG) emissions could be ascribed to the use of fertilizers and fuel consumption. Under the same fertilization regime, ranking the tillage patterns with respect to the value of the crop yield, profit, CF, energy use efficiency (EUE) or energy productivity (EP) for either wheat or maize always gave the same sequence of SRT>RT>CT>NT. For the same tillage, the energy consumption associated with HF was higher than IF, but its GHG emissions and CF were lower while the yield and profit were higher. In terms of overall performance, tilling is more beneficial than NT, and reduced tillage practices (RT and SRT) are more beneficial than CT. The fertilization regime with the best overall performance was HF. Combining SRT with HF has significant potential for reducing CF and increasing EUE, thereby improving sustainability. Adopting measures that promote these optimizations can help to overcome the challenges posed by a lack of food security, energy crises and ecological stress.