The employees of the Laboratory of Soil Carbon and Microbial Ecology, in collaboration with the All-Russian Research Institute of Reclaimed Lands, conducted a comprehensive long-term field experiment at the Gubino agricultural polygon. The objective of the experiment was to evaluate the effects of composts derived from chicken manure on soil fertility and ecological functions, specifically focusing on the physicochemical and biological properties of the soil, as well as its organic matter. A total of 21 experimental sites, covering an area of 70 m2each, were established. The study considered various types of composts derived from chicken manure, employing different degrees of fermentation technologies and recommended and high doses. The main goals of this long-term field experiment were to assess the impact of chicken manure-based composts on the content, chemical composition, and pools of soil organic matter, determine the potential for sequestration and carbon storage of chicken manure in the soil, and investigate the abundance, taxonomic composition, and activity of the soil microbiome in response to chicken manure and compost application.