An analysis of the energy efficiency of winter rapeseed biomass under different farming technologies. A case study of a large-scale farm in Poland

The article presents the results of a three-year study investigating the impact of production technology on the energy efficiency of winter rapeseed produced in large-scale farms. Rapeseed biomass produced in a high-input system was characterized by the highest energy demand (30.00 GJ ha⁻¹). The energy demand associated with medium-input and low-input systems was 20% and 34% lower, respectively. The highest energy value of oil, oil cake and straw was noted in winter rapeseed produced in the high-input system. In the total energy output (268.5 GJ ha⁻¹), approximately 17% of energy was accumulated in oil, 20% in oil cake, and 63% in straw. In lower input systems, the energy output of oil decreased by 13–23%, the energy output of oil cake – by 6–16%, and the energy output of straw – by 29–37% without visible changes in the structure of energy accumulated in different components of rapeseed biomass. The highest energy gain was observed in the high-input system. The low-input system was characterized by the highest energy efficiency ratio, at 4.22 for seeds and 9.43 for seeds and straw. The increase in production intensity reduced the energy efficiency of rapeseed biomass production by 8–18% (seeds) and 5–9% (seeds and straw). - Highlights: • Energy inputs in the high-input production system reached 30 GJ ha⁻¹. • Energy inputs in the medium- and low-input systems were reduced by 20% and 34%. • Energy gain in the high-input system was 15% and 42% higher than in other systems. • Energy ratio in the high-input system was 5–18% lower than in the low-input system.