ИСТИНА

Russian Chernozem is one of the most fertile soil on the globe. Dokuchaev (1885) called it “beneficial soil, which constitutes the indigenous, incomparable wealth of Russia”. The belt of Chernozem soils was under ploughing at least 3000 years, and the most intensive during the last 300 years. This exploitation of soil caused its erosion and decrease of the depth of upper, most fertile horizons. It is important to understand the current level of soil losses for the sustainable agriculture on them. The assessment of the total soil loss from cultivated land was undertaken for the Chernozems-Kastanozems belt of European Russia and Siberia, based on the results of the National Soil survey for the administrative regions and the detailed study of sentinel catchments, located in different parts of the Russian Plain within upland areas. The soil profile truncation method was used to assemble data on soil erosion for the period of intensive agriculture. This method allows evaluating the total soil losses, including water, wind and tillage erosion and loss of soil when harvesting root crops. The total volume of soil, eroded on arable lands during the period of intensive ploughing in the Chernozems-Kastanozems soil belt of Russian Federation was amounted to 33.4x109 m3. The average value of the mean gross erosion rate was estimated at ~6 t ha-1 yr-1 for Chernozems and ~4.8 t ha-1 yr-1 for Kashtanozems. For individual fields this rate of erosion vary in the broad range from nearly zero to 60-80 t ha-1 yr-1. Washed-out soil matter from cultivated land is delivered to fluvial networks and about 90% of eroded soil matter is deposited in their upper reaches. The thickness of these deposits, containing great amount of organic carbon, is about 1-2 m at the bottoms of dry valleys. Key words: Russia, soil erosion, Chernozems, soil truncation method