Field-based experimental greenhouse gas emissions and energy use efficiency study of sorghum x sudan grass hybrid growth in a semi-arid region

The aim of this research was to define the energy use and greenhouse gas (GHG) emissions associated with the production of sorghum x sudan grass (SSG) hybrids. Energy use efficiency (EUE) indicators and GHG ratios were computed for the 2021 and 2022 growth seasons. Energy inputs, including diesel, fertilizers, seeds, and agricultural machinery, were assessed based on their energy equivalents, while energy outputs were calculated based on the energy value of the biomass produced. The analysis differentiated between direct energy inputs (human labor, diesel, irrigation, and electricity) and indirect energy inputs (machinery, fertilizer, and seed). Energy inputs were further divided into renewable energy sources (human labor, water, seeds) and non-renewable energy sources (fertilizer, fuel, and electricity). GHG ratios were determined by calculating the carbon footprint of the inputs in the production process. The average energy input and output for SSG hybrid production were computed to be 20445.65 MJ ha−1 and 370040.77 MJ ha−1, respectively. The research defined an EUE of 18.10, with a specific energy of 1.02 MJ kg−1, an energy productivity of 0.98 kg MJ−1 and a net energy value of 349595.12 MJ ha−1. Direct and indirect energy inputs were computed to be 12901.65 MJ ha−1 (63.10 %) and 7544 MJ ha−1 (36.90 %), while renewable and non-renewable inputs were calculated to be 4718.30 MJ ha−1 (23.08 %) and 15727.35 MJ ha−1 (76.92 %), respectively. The total GHG emissions were 1324.55 kgCO2-eq ha−1 and the GHG ratio was 0.07 kgCO2-eq ha−1. The production profitability ratio was calculated as 3.35. SSG hybrid production proved to be highly profitable for the 2021 and 2022 production seasons in terms of EUE.