ИСТИНА

Soil particles eroded from cultivated lands are one of the important sources of water pollution in agricultural regions. Global warming is seriously affected the intensity of erosion processes around the world. The southern half of the Russian plain is the main agricultural region of Russian Federation with high proportion of cultivated lands in the southern part of the forest, forest-steppe and steppe zones. Few typical small catchments were selected in the different landscape zones of the Russian Plain for the evaluation of the soil losses from cultivated lands for two time intervals. Bomb-derived and Chernobyl-derived 137Cs were applied as a time marker for evaluation of deposition rates in the bottom of the first order valley bottoms serving as the major sediment sink for the sediment eroded from cultivated fields. The detail DEMs of the each catchment were constructed based on combine application of standard tacheometric survey and DGPS survey. Large scale morphological mapping was undertaking for the each catchments for the identification of the sediment pathways from the cultivated field to the valley bottom. Erosion models were used for the assessment of the soil erosion rates for the each study catchment. It was found mostly based on the evaluation of the deposition rates that soil losses decrease in the all landscape zones during period 1986-2015(6) if it is compare with period 1963 – 1986. However the local climatic conditions are influenced on the rate of soil losses reduction in the each landscape zones. Identified features of sediment redistribution rates for the each study site are discussed in the context of the influence of global warming and crop rotation changes