Optimized tillage improves yield and energy efficiency while reducing carbon footprint in winter wheat-summer maize rotation systems.

Conventional tillage consumes a lot of energy and produces a lot of greenhouse gases (GHGs), with quite limited contribution to food production. Optimizing tillage practices is an important measure to save energy, protect the environment and increase productivity. Based on this concept, a field experiment of two years duration (2019-2021) was performed to assess the impacts of various tillage techniques on grain yield, energy balance, carbon footprint (CF), and economic benefits of a winter wheat-summer maize rotation system in the Loess Plateau of China. The treatments included conventional tillage (CT), no-tillage (NT), ridge cultivation with no-tillage (RNT), and occasional tillage (OT). This study is the first to evaluates the economic and environmental benefits of OT and RNT in dry farming. The total annual average greenhouse gas emissions calculated through the life cycle assessment are 2869.2-3407.6 kg CO2-eq·ha-1, and the energy consumption and output are 28.2-37.7 GJ ha-1 and 575.2-659.0 GJ ha-1, respectively. The net ecosystem economic benefit is 26,206.6-34,787.4 CNY ha-1. Compared with CT, annual crop yields of RNT, OT and NT have increased by 13.5%, 15.4% and 4.0%, respectively, energy utilization efficiency has increased by 47.8%, 31.2% and 35.3%, and carbon footprint has been reduced by 79.3%, 46.2% and 73.2%, economic efficiency has increased by 32.7%, 29.8% and 19.6%, respectively. Despite reducing energy consumption and carbon footprint, NT has no significant impact on annual crop yields. Optimizing tillage practices (RNT and OT) can achieve higher economic and environmental benefits. The Z-score shows that RNT in dryland agroecosystems can be used as a promising tillage practice to boost crop productivity, energy efficiency and economic efficiency, reduce CF, and achieve sustainability. RNT can be selected as the recommended agricultural management measure suitable for areas with similar climatic patterns in the Loess Plateau.