ECONOMIC EFFICIENCY OF MAIZE CULTIVATION USING DIGESTATE IN UKRAINE

This article presents the results of a study on the economic efficiency of growing corn for grain, silage, and biomethane production, with the corresponding quality of the products obtained. The research was conducted on the experimental field of Vinnytsia National Agrarian University under ORGANIC-D TOV conditions in 2023-2024. The cultivation techniques included elements that are generally accepted for the cultivation area, with the exception of the factors under study. The yield of grain and green mass, the quality of the products obtained, and the yield of biomethane from corn silage were determined in accordance with established methods. Harvesting and yield accounting were carried out manually on each experimental plot. The fertilisation options studied involved the use of mineral fertilisers (N90P90K90), micronutrients (Nanovit corn) and digestate obtained through anaerobic fermentation in biogas plants. Digestate was applied at different times: basic, pre-sowing fertilisation and top dressing at a rate of 60 t/ha. It was established that the indicators of the gross grain production value, by the studied maize hybrids, averaged as follows: Amaros (FAO 230) – 51,380.3 UAH/ha, P 8754 (FAO 240) – 52,521.5 UAH/ha, Bigbit (FAO 290) – 69,193.7 UAH/ha, Bohatyr (FAO 290) – 79,784.3 UAH/ha, KWS 381 (FAO 350) – 80,730.6 UAH/ha, KWS Intelligence (FAO 380) – 84,515.9 UAH/ha, DN Anshlag (FAO 420) – 83,875.8 UAH/ha, and P 0217 (FAO 460) – 84,088.8 UAH/ha. The application of digestate from biogas plants increased the gross production value of grain maize by 8,621–19,392.9 UAH/ha (14.6–26.5%) and of silage maize by 5,448.5–9,804.3 UAH/ha. The use of mineral fertilisers in combination with the microfertiliser “Nanovit Corn” increased these values by 10,270.5–18,954.5 UAH/ha (16.4–27.6%) and 3,359.0–8,804.0 UAH/ha, respectively, compared to the control where no fertilisers were applied. The highest profitability of grain maize cultivation was recorded with triple digestate application (main, pre-sowing, and top dressing): Amaros (FAO 230) – 103.7%, P 8754 (FAO 240) – 118.5%, Bigbit (FAO 290) – 150.3%, and Bohatyr (FAO 290) – 191.6%. For KWS 381 (FAO 350), KWS Intelligence (FAO 380), and P 0217 (FAO 460), the maximum profitability values (186.7–195.5%) were obtained when digestate was applied only as a pre-sowing fertiliser. The hybrid DN Anshlag (FAO 420) demonstrated the highest profitability (183.5%) under the mineral fertiliser + microfertiliser “Nanovit Corn” scheme. A similar trend was observed for the cultivation of silage mass of the studied maize hybrids. The biogas yield from 1 hectare of the studied maize hybrids, corresponding to the respective green mass productivity, ranged from 6,645 to 10,111 m³. Such variations in biogas volume also affected the value of the produced output. The highest profitability indices for cultivating silage maize for biogas production were recorded under triple digestate application (main, pre-sowing fertilisation, and top dressing). For the hybrids, these values amounted to: Amaros (FAO 230) – 200.6%, P 8754 (FAO 240) – 209.0%, Bigbit (FAO 290) – 189.6%, Bohatyr (FAO 290) – 221.8%, KWS 381 (FAO 350) – 237.3%, KWS Intelligence (FAO 380) – 224.8%, DN Anshlag (FAO 420) – 208.8%, and P 0217 (FAO 460) – 210.3%, which exceeded the level of the control variant without fertilisers by 40.6–67.3%. From the point of view of economic feasibility, medium-late maturity hybrids are the most effective for growing silage maize.