Abstract <p>A quantitative assessment of the thickness and volume of eroded soil material over the entire period of agricultural use was performed for a small catchment in Tula oblast with leached chernozems (Luvic Chernic Phaeozems) and podzolized chernozems (Luvic Greyzemic Chernic Phaeozems). The total soil loss was determined by comparing the residual thickness of humified soil horizons on plowed slopes with that in uneroded soils of nearby flat watersheds. The washout layer was calculated using the SERSAL model developed at the Department of Soil Erosion and Riverbed Processes, Faculty of Geography, Lomonosov Moscow State University on the basis of the Universal Soil Loss Equation adapted for conditions of Central Russia. Changes in the spatial position of boundaries of plowed land, farming systems, crop composition, and other erosion factors over the course of three and a half centuries of agricultural development in the catchment were reconstructed on the basis of archival and published data. The obtained values were used as input parameters for the model. The comparison of the simulated results and actual soil losses on plowed slopes showed their similarity. The volume of soil loss calculated by the Cell variant of the SERSAL model using an uneroded soil standard of 85 cm to determine total soil losses at borehole points was by 1.2% lower than the actual loss. This confirms the importance of quantifying the contribution of mechanical erosion to the total soil loss on plowed slopes. For adequate modeling, it is important to take into account changes in the microrelief of plowed land during the study period due to erosion-accumulation processes and mechanical erosion.</p>