The energy balance of the production process of Brassica oilseed crops in Poland

This article presents the results of an experiment investigating the energy efficiency of production technologies for selected species and botanical forms of Brassica oilseed crops – BOCs (winter and spring oilseed rape, winter and spring camelina, crambe, white and Indian mustard, and oilseed radish) under the agroecological conditions of northeastern (NE) Poland. The field experiment was conducted from 2021 to 2024 at the Bałcyny Experimental Station (53°35'46.4'' N, 19°51'19.5'' E). The experiment was arranged in a randomized complete block design with three replications. We calculated the energy gain and energy efficiency ratio for each BOCs production technology, taking into account the energy input and energy output from seed and total biomas yields (seed and straw). The production technologies of winter oilseed rape and winter camelina were characterized by the highest energy demands (26.1 and 20.9 GJ ha⁻¹, respectively), while spring BOCs required 35–47 % less energy. Winter oilseed rape achieved the highest seed yield (5.41 Mg ha⁻¹) and seed energy gain (120.61 GJ ha⁻¹), with alternative BOCs having seed yields 60–88 % lower and energy gains 3–51 times lower. Straw yields were highest in winter oilseed rape and oilseed radish (6.63 and 7.82 Mg ha⁻¹ DM, respectively), while other BOCs had straw yields 51–74 % lower. When only seeds are used for energy, the cultivation of winter oilseed rape provides the highest net energy gain per unit area and the highest energy efficiency ratio, making it a favorable choice for any farm, regardless of available resources (land, capital). When total biomass (seeds and straw) is utilized, large farms benefit from cultivating oilseed radish due to its high energy efficiency, whereas in small farms, winter oilseed rape remains the best option, ensuring the highest net energy gain per unit area. ● Energy inputs were 35–47 % higher in winter oilseed crops than in spring crops. ● Seed and straw yields were highest in winter oilseed rape (5.41 and 7.82 Mg ha⁻¹ DM). ● The energy efficiency ratio of seeds was highest in winter oilseed rape production. ● The energy efficiency ratio of total biomass was highest in oilseed radish production.