Agrogenic eutrophication refers to the artificial enrichment of soil with organic carbon and nutrients in result of applying mineral and organic fertilizers to increase soil fertility and plant productivity. Eutrophication of gray forest soils (Luvic Retic Greyzemic Phaeozems (Loamic)) was created by annual application of increasing doses of mineral (N 90–360, P2O5 75–300 and K2O 100–400 kg/ha) and organic (fresh cattle manure from 25 to 100 t/ha) fertilizers under plants of a 5–field crop rotation for 9 years in microplots experiment. The NPK amounts applied with the manure were approximately equal to the corresponding doses of mineral fertilizer. The rates of soil enrichment by Corg under mineral and organic fertilizer systems were, respectively, 0.29–0.38 and 0.76–1.56 g/kg per year, Ntot – 0.04–0.06 and 0.06–0.09 g/kg per year, available P2O5 – 4–57 and 11–55 mg/kg per year, available K2O – 5–44 and 6–31 mg/kg per year. The fertilizer doses under both systems were the most significant factor in the accumulation of nitrate nitrogen, available forms of phosphorus and potassium in the soil, while the Ntot contents was controlled by the duration of fertilizer application. The Corg content in the soil with organic and mineral fertilizers depended on the dose of manure and the duration of NPK application, respectively. Soil eutrophication with mineral fertilizers was accompanied by a decrease in soil pH, and eutrophication with organic fertilizers, on the contrary, led to an increase in pH. It is emphasized that over–fertilization and long–term use of fertilizers are the main factors in the development of soil eutrophication and the concomitant change in soil pH.