COMPARATIVE CHARACTERISTICS OF DIGESTATE AND OTHER ORGANIC FERTILIZERS

The number of biogas plants in Ukraine is constantly growing which increases the production of by-products. The biochemical composition of them has not been fully investigated. Digestate samples were collected at Biogas Ladyzhyn, division of Vinnytsia Ptakhofabryka LLC. The analysis of their agrochemical composition was carried out in the certified laboratories of Zakhidnyi Bug PE, Kompania Zemlerob LLC, and Kolos Agrofirma LLC. The analyzes were carried out in accordance with DSTU and the corresponding methodical recommendations. It was established that digestates contain a significant amount of macronutrients and are not inferior to chicken droppings in terms of this indicator. A high content of macro- and micronutrients per dry matter can be valuable for a fertilizer product, taking into account that it needs to be disposed of at a small distance from the biogas plant. Moreover, each batch of digestate is a separate fertilizer that has its own unique macro- and microelement composition and content of organic substances. It requires a preliminary agrochemical analysis and only on its basis the calculations and taking into account the biological features of development and the possible productivity of a certain agricultural crop can determine the permissible application doses. Digestate does not significantly affect the mycological condition of dark grey forest soil, even at high doses of its introduction (30–50 m3/ha), compared with traditional fertilization with aqueous ammonia at a dose of 110 kg/ha of nitrogen. Compared to traditional types of organic fertilizers, poultry dropping digestate can be considered a valuable local complex organo-mineral fertilizer product of local importance for improving plant nutrition and the balance of nutrients in the soil. Currently, there are no restrictions on its implementation as a fertilizer product of organic origin. Therefore, it is necessary to continue research on the maximum doses of its introduction and the efficiency of various technologies of application to agricultural crops.