Graphical Abstract: The paper deals with the evaluation of the intensity of certain soil biochemical processes (e.g. soil organic C mineralization) at Organic and mixed Mineral+Organic fertilization of typical chernozem in crop rotation dynamics (for 6 years) by use of eco-physiological indicators of biological soil quality: microbial biomass carbon, basal soil respiration, as well as, microbial and metabolic quotients. Soil sampling was performed from a long-term field crop experiment, which has been established in 1971 at the Balti steppe (Northern Moldova). The crop types had a more considerable impact on the soil microbial biomass accumulation and community biochemical activity compared to long-term Organic or mixed
Mineral + Organic fertilizers amendments. The Org fertilization system doesn’t make it possible to avoid the loss of organic C in arable typical chernozem. The organic fertilizer (cattle manure) is able to mitigate the negative consequences of long-term mineral fertilization.