Tillage and Irrigation Impacts on the Efficiency of Fossil Fuel Utilization for Hungarian Vetch Production and Fuel-Related CO2 Emissions

Improving energy efficiency in tillage is critical for developing sustainable agriculture and mitigating fuel-related CO2 emissions. However, data on energy efficiency and CO2 emissions across various tillage-sowing practices remain scarce in terms of vetch production. The study aimed at evaluating the impact of four tillage-sowing practices (conventional tillage [CT], Reduced-I and II, and no-tillage [NT]) on the fuel consumption, energy productivity, and fuel-related CO2 releases in Hungarian vetch production. The study was performed in Turkey, in semiarid conditions using two water applications (rainfed and irrigated) under two different crop rotations (rainfed: vetch-wheat-fallow and irrigated: vetch-wheat-sunflower). The study findings revealed that while CT had the highest diesel-fuel consumptions (52.2 L/ha in irrigated and 53.1 L/ha in rainfed), the lowest values were determined in NT (16.4 L/ha in irrigated and 16.6 L/ha in rainfed). Total energy requirements were the highest in CT, and determined 11827.4 MJ/ha (5229.1 MJ/ha direct and 10502.5 MJ/ha nonrenewable) in irrigated rotation and 9328.5 MJ/ha (3013.6 MJ/ha direct and 8004.6 MJ/ha nonrenewable) in rainfed conditions. Moreover, CT provided the lowest energy ratio (4.41 in irrigated and 3.87 in rainfed). NT practice required significantly lower total (20.6% in irrigated and 27.8% in rainfed), direct (52.5% in irrigated and 68.8% in rainfed), and nonrenewable energies (23.1% in irrigated and 32.3% in rainfed) and provided higher energy ratio (24.0% in irrigated and 53.2% in rainfed) compared to CT. Irrigation increased energy gain by 48.2% on average. Conservation tillage logarithmically reduced CO2 emissions in both rotations. NT and reduced tillage practices generated 68.7% and 42.2% lower emissions on average compared to CT (151.1 kg CO2/ha), respectively. It was concluded that NT can be a suitable practice to achieve higher energy efficiency and lower CO2 emissions in vetch production. However, reduced tillage can be favorable due to the limited application of NT in most countries.