ASSESSMENT OF OILSEED RADISH (Raphanus sativus L. var. oleiformis Pers.) PLANT BIOMASS AS A FEEDSTOCK FOR BIOGAS PRODUCTION

ABSTRACT The potential of oilseed radish at two sowing dates for use as a raw material in biogas (biomethane) production based on laboratory anaerobic digestion with the addition of inoculum with a 60-day incubation period was investigated. The results of biogas productivity were compared with traditional cruciferous species used for bioenergy purposes. In the spring-sown variants, the achievable level of ground bioproductivity of oilseed radish was set at 25.17 t ha−1 of raw and 3.20 t ha−1 of dry matter, which provided a biomethane yield (SMY) of 320.07 ± 31.39 LN kg−1ODM and an indicator of methane accumulation intensity (Rm(ef)) of 130.76 ± 10.20 LN kg−1ODM d−1 with an appropriate biochemical portfolio of the formed biomass. During the summer sowing period, the average bioproductivity of oilseed radish was 18.42 t ha−1 in raw weight and 2.81 t ha−1 in dry matter, which provided an SMY of 262.97 ± 24.64 LN kg−1ODM and an Rm(ef) of 122.22 ± 3.62 LN kg−1ODM d−1 with its appropriate biochemical composition. The maximum level of biomethane production from oilseed radish was achieved with spring sowing under the conditions of 2021, resulting in the following technological parameters of productivity: MS 55.84 ± 9.39%, SMY 359.25 ± 11.24 LN kg−1ODM, Rm(ef) 138.15 ± 1.78 LN kg−1ODM d−1, Rm(full) 31.51 ± 1.69 LN kg−1ODM d−1, t50 4.12 ± 0.34 days, and λ 1.74 ± 0.17 days.