Аннотация:Significant climate and crop rotation changes have taken place over
the last few decades in the Central Chernozem zone of European
Russia. These have considerably influenced sediment redistribution
rates within agricultural catchments. Quantitative assessments of
soil losses from cultivated lands and sediment redistribution intensity
have been made using an integrated approach for typical catchments
of Central Russia located near the city of Kursk in the River Vorobzha
basin. Combined application of the caesium-137 (137Cs) technique,
erosion models, the soil morphological method and large-scale
geomorphic mapping with detailed evaluation of the area of each
typical morphological unit indicated that soil erosion rates on arable
hill slopes decreased by about 1.5 times during the last 25 years (yr)
compared with rates during the previous quarter century. Sediment
delivery from cultivated fields into the River Vorobzha valley also
decreased by up to three-fold over the same timeframes. The main
reason for these changes was the considerably reduced surface
runoff during the spring snowmelt period. In addition, the approach
employed made it possible to quantify the effectiveness of soil conservation
measures (SCMs) introduced within the small experimental
sub-catchments occupying part of the study area. Application of
SCMs reduced soil losses from cultivated fields by 2.5 times. Most of
the eroded sediment and sediment-associated 137Cs has been redeposited
within the cultivated fields and adjacent dry valley bottoms.
It can be concluded that taking an integrated approach is the most
appropriate strategyfor assessing soil degradation and determining
both localized and off-site soil and nutrient sinks.