Energy efficiency of maize hybrids cultivation for biogas production with using macro- and microfertilizers

Topicality. Nowadays, the main purpose of agro-industrial complex and renewable energy is to increase the productivity of corn for grain and silage. For biogas production the proper selection of maize hybrids and energy assessment of their cultivation technology is needed. Issues. Optimization of technological methods and increasing the yield per area unit is one of the ways to improve the energy efficiency of crop production, including for the purposes of bioenergy. Energy analysis assists to compare energy consumption for growing crop and energy content in the obtained yield. Aim. To determine the influence of macro- and microfertilizers on the energy efficiency of growing maize hybrids for biogas production. Materials and Methods. The research was conducted in 2019–2021 in the “Poultry Farm Korobivsky" Andrushivka district of Zhytomyr region. In a three-factor experiment, it was studied maize hybrids: Amaroc, Bogatyr, KWS 381, Karifols; macrofertilizers, kg/ha: without fertilizers, N90Р60К60, N120Р90К90; microfertilizers: without application, YaraVita Teprosyn NP + Zn seed treatment (5 l/t) and spraying maize in the 3–5 leaves stage with YaraVita Maize Boost (4 l/ha), seed treatment (0.15 kg/t) with YaraTera Tenso Cocktail and spraying maize in the 3–5 leaves with Yara Vita Kombiphos (3 l/ha). Results. It was found that the biogas output for the mid-early maize hybrids Amaroc and Bogatyr was 9062.0–13716.3 m3/ha, and for the mid-ripening KWS 381 and Karifols was higher by 9.8–36.5 % (11635.3–15589.5 m3/ha). Biogas output was higher by 15.2–30.9 % and 1.8–3.6 % due to using macrofertilizers and microfertilizers compared to the variants without their application. There was no significant difference in biogas output between the second and third variants with microfertilizers. It was identified that energy efficiency ratio (Ke) increased for studied maize hybrids when N90Р60К60 and N120Р90К90 were applied. Conclusions. The highest biogas and energy output was 15589,5 m3/ha and 333,6 GJ/ha was obtained for the mid-ripening hybrid Karifols when pre-sowing seed treatment with YaraTera Tenso Cocktail (0.15 kg/t) and spraying maize in the 3–5 leaves stage with YaraVita Kombiphos (3 l/ha) were carried out on the background of N120Р90К90. In our opinion, for biogas production, the cultivation of Amaros, Bogatyr, KVS 381 and Carifols hybrids is more efficient when used pre-sowing seed treatment with Yara Tera Tenso Cocktail (0.15 kg/t) and spraying maize with YaraVita Kombiphos (3 l/ha) in the 3–5 leaves stage without macrofertilizer application that provides the highest energy factor in the range of 7.7–9.3. Key words: biogas output, pre-sowing seed treatment, energy output, energy consumption, energy efficiency ratio.