The experiment was carried out in 1999-2001 on degraded chernozem developed from loess. Three species were sown in a crop rotation link: field bean with top inflorescence and traditional - undersown or stubble catch crop - winter or spring wheat. These experiments investigated the effects of undersown and stubble catch crop management on the accumulation of soil organic carbon. Soil was sampled from layer 0-30 cm, at the following dates: 1st decade of November, 1st decade of March, 2nd decade of May and 1st decade of June. The research proved that the undersown and stubble catch crops might be an important component of crop rotation, particularly in case of the residues a lot of mineral nitrogen from previous crop (field bean) in the sites for wheat. Ploughing down of the undersown and stubble catch crop increase organic carbon contents, improve the soil condition, and as a result increase yield of subsequent crop. Surface plant biomass mulching and soil cultivation before spring wheat sowing not differentiated organic carbon contents in the 0-30 cm layer.