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, it is essential to optimize the tillage and fertilization practices. To assess the effect of tilling and fertilization practices in the wheat-maize cropping systems, we carried out a three-year field experiment designed to quantify the carbon footprint (CF), and energy efficiency of the cropping systems in the North China Plain. As the study parameters, we used 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)). Our results indicated that the most prominent energy inputs and greenhouse gas (GHG) emissions could be ascribed to the use of fertilizers and fuel consumption. Assuming the same fertilization regime, ranking the tillage patterns with respect to the value of the crop yield, the profit, the CF, the energy use efficiency (EUE) or the energy productivity (EP) for either wheat or maize always gave the following result: 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 better. In terms of the overall performance, tilling is more beneficial than NT, and reduced tillage (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, improving the sustainability. Adopting measures promoting these optimizations can help overcome the challenges posed by lack of food security, energy crises and ecological stress.