Evaluation of soil‐loss contribution areas on loess soils in SouthEast Poland

Results of soil‐loss assessments on loess‐derived silt soils are presented. The studies were conducted on plots of different length maintained in continuous bare fallow conditions. Analysing runoff events separately, soil losses per unit area varied with plot length. Description of the soil‐erosion process in terms of (1) maximum soil loss per unit area and (2) the effective distance of soil transport allows us to overcome problems with data interpretation. Smaller values of soil loss per unit area could then be connected with (1) impeded development of erosion process on plots of shorter length and (2) over‐estimation of soil loss contribution area on longer plots. The method of determination of soil‐loss contribution area was the main reason of the differences between soil losses, observed and predicted from the Universal Soil Loss Equation. Studies conducted showed that eroded soil material was transported short distances (from 2 to 13 m). The maximum soil loss per unit area was well correlated with rainfall amount, whilst the effective distance of soil transport was affected by many factors, including rainfall amount and initial state of soil roughness.