Assessment of soil erosion on arable land using 137Cs measurements:: a case study from Jaslovske Bohunice, Slovakia

This study was carried out to obtain a representative set of data on long-term erosion rates from a pilot area located close to the Jaslovske Bohunice village, in western Slovakia using the Cs-137-method. The study area chosen was representative of the hilly loess cultivated areas of Slovakia. The sampling strategy was based on a multiple transect approach. Analyses of the samples for Cs-137 activity were made at the Nuclear Power Plant Research Institute, Jaslovske Bohunice. The Cs-137-method was used to obtain long-term estimates of soil erosion in the Jaslovske Bohunice site, a representative hilly loess cultivated area of Slovakia. The estimated reference Cs-137 inventory was 2910 Bq m(-2), with a coefficient of variation of 4.3%. Examination of the Cs-137 redistribution in relation to the topography of the study area revealed that, within individual transects the Cs-137 inventories were closely related to major landforms. The Cs-137 inventories were considerably lower on the slopes than on the plateau and they were highest in the valley. However, when plotted against a selection of individual quantitative slope parameters, i.e. the S and the LS factors of the USLE or slope inclination, the correlations obtained were weak. Three conversion models, i.e. the proportional model (PM), the simplified mass balance model (MBM1) and the standard mass balance model (MBM2), from the set of models developed at Exeter University, Great Britain were selected to interpret the resulting Cs-137 measurements into soil erosion/deposition rates. The mean erosion rates estimated with the PM were 22.4, 35.6 with MBM1 and 17.3 t ha(-1) per year with MBM2. There was a good agreement between the average of these mean erosion rates (25.1 t ha(-1) per year) for the Jaslovske Bohunice site and the estimated mean soil erosion rate obtained for small erosion plots (15 t ha(-1) per year) for conditions similar to the study site. Nevertheless, further research on the application of the Cs-137-method, in particular the independent validation of the results obtained, is needed. Several issues requiring further study have been highlighted. (C) 2002 Elsevier Science B.V. All rights reserved.