Agroecological monitoring of manure quality for growing pigs on an industrial basis

Abstract

Goal. To study the quality and safety of liquid non-stick pig manure obtained from the growing pigs on an industrial basis. Methods. Laboratory studies of the chemical composition of pig manure were carried out in the measuring laboratory of agrochemical research, environmental safety of land, and quality of products of the Institute of Agriculture of Polissia of NAAS under the regulations in force in Ukraine. The main nutrients were determined under State Standards and ISV (International Selective Version). Results. It was established that liquid non-polluting manure obtained while growing pigs on an industrial basis contained all the necessary nutrients for plant cultivation, although their amount was much lower than in chicken manure. It met the quality and safety indicators of liquid manure and could be used in the production of agricultural products and raw materials. During the years of research, pig manure had in its composition 0.19–0.21% of total nitrogen, 0.12–0.13% of total phosphorus, and 0.09–0.10% of total potassium. The content of dry matter and ash was in the range of 5.84–6.52% and 1.76–1.91%, respectively. The acidity of liquid pig manure varied from neutral to slightly alkaline in the range of 6.93–7.50 units. Pig manure also had a significant amount of trace elements in its composition: mass fraction of copper ranged from 5.91 to 6.59 mg/kg, zinc — from 13.93 to 15.48 mg/kg, cobalt — from 0.27 to 0.31 mg/kg, manganese — from 8.55 to 9.96 mg/kg, iron — from 9.88 to 10.79 mg/kg. Characterizing the qualitative indicators of dust-free pig manure obtained for growing pigs in LLC «DFU AGRO,» by years of research, a trend to increase the nutritional indices (NPK) and trace elements (Cu, Zn, Fe, Mn, Co), as well as a decrease in the content of dry matter, ash, heavy metals in 2024 compared to 2022 figures were established. The content of heavy metals was at the level of toxicants in soils: lead — 1.92–2.13 mg/kg, cadmium — 0.079–0.091 mg/kg, mercury — 0.0021–0.0023 mg/kg. Conclusions. According to the results of the conducted studies, it was established that, according to all quality indicators, pig manure met agronomic requirements for the quality of fertilizers for use in agricultural production, in particular in organic production. The obtained results require further in-depth scientific research to identify violations of ecological balance in the zone of influence of modern pig complexes after the application of these fertilizers into the soil.