Use of soil profile truncation to estimate influence of accelerated erosion on soil cover transformation in young morainic landscapes, North-Eastern Poland

• Changes in soil properties due to erosion are described
• Five classes of vertical texture contrasted soils truncation are defined
• Maps of soil cover transformation were generated and overlapped on DEM
• The average values of soil truncation is about 40-50 cm
• The colluvial deposits thickness reach up to 3 m
• Anthropogenic character of soil erosion is proved

Human-induced erosion is one of the key factors leading to the soil degradation. Agricultural, undulating or hilly morainic areas of North-Eastern Poland are exposed to this negative process. This paper elucidates the influence of accelerated soil erosion on soil cover in young morainic landscapes of North-Eastern Poland (Brodnica Lake District). Detailed pedological investigation (21 soil pits and 375 augerholes) were carried out within two study sites (forest and agricultural). A comparison of fully developed forest reference soil pedons with arable soil has been made. Five classes of soil truncation have been distinguished. According to the identified degrees of truncation, maps of soil cover transformation, caused by accelerated erosion, were generated and overlapped on Digital Elevation Models (DEMs). Eroded soils overlap 39.5% of agricultural area and 2.5% of forest site. The widespread occurrence of strongly and completely eroded pedons (respectively 7.4% and 5.4%), only in the agricultural areas, provides intense anthropogenic impact on soil cover in the agriculture areas of North-Eastern Poland. The average values of soil reduction are about 40–50 cm. In the case of completely eroded soils it exceeds even 100 cm. Truncation of pedons with abrupt textural change due to the slope processes leads to the disappearance of vertical textural contrasts and the formation of new soil units. The evidence of erosion from the topsoils is mainly the decrease in the content of organic matter and calcium carbonate enrichment. The effect of intensive slope processes is widespread occurrence of thick (up to 3 m) colluvial deposits.