Meat and Bone Meal and the Energy Balance of Winter Oilseed Rape—A Case Study in North-Eastern Poland

A two-year field experiment was conducted in Poland to determine energy efficiency (EE) in the production of winter oilseed rape (WOR) in different fertilization: (i) zero-fertilization; (ii) 158 kg N ha−1, 45 kg P ha−1 and 145 kg K ha−1 as mineral fertilizer (NPK); (iii) 1.0 Mg ha−1 meat and bone meal (MBM), 79 kg N ha−1 and 145 kg K ha−1 as mineral fertilizer; (iv) 1.5 Mg ha−1 MBM, 40 kg N ha−1 and 145 kg K ha−1 as mineral fertilizer; and (v) 2.0 Mg ha−1 MBM and 145 kg K ha−1 as mineral fertilizer. The replacement of NPK with MBM decreased energy inputs in WOR production by 20−55%. The NPK had a greater (16–21%) effect on seed yield formation than MBM. The replacement of NPK with MBM decreased the energy output of seeds (14–21%) and total biomass (12–20). The replacement of NPK with MBM decreased (6–13%) the energy gain from seed production. The application of MBM improved the EE ratio in the production of seeds (10–81%) and total biomass (11–85%) relative to NPK. The EE ratio of WOR production increased with a rise in MBM doses.