PurposeExogenous Organic Matter (EOM) enriches and regenerates the soil, while solving the problem of landfilling waste such as sewage sludge and bottom sediments. The main purpose of the presented study was to estimate the influence of type and dosage of applied EOM on soil biological characteristics and supporting plant growth, with consideration of inoculation with PGPR (plant growth-promoting rhizobacteria).Materials and methodsThe soil samples were characterized by measuring key enzyme activities, determining the community-level physiological profiling (CLPP) using Biolog EcoPlates, abundance of microorganisms and evaluation physical and chemical properties.Results and discussionApplication of EOM mostly increased enzyme activity as well as overall metabolic activity compared to control sample. Increasing the dose of poultry manure and sewage sludge from 20 to 40 t ha−1 increased dehydrogenase, acid and alkaline phosphatase activity. Moreover, the addition of EOM affected the metabolic activity and the number of selected groups of bacteria and fungi.ConclusionsIn the research it was proven that application of EOM leads to relatively rapid and positive changes in soil biological activity. The research also confirmed that the supporting factor for plant growth was the inoculation with PGPR bacteria. This approach, together with the reuse of organic wastes may become an attractive approach in sustainable cropping systems in a circular economy system.Graphical