No abstract

On the basis of detailed rill surveys carried out on bare plots of different lengths at slopes of 12 per cent, basic rill parameters were derived. Rill width and maximum depth increased with plot length, whereas rill amount and cross-sectional area, expressed per unit length, remained similar. On smaller plots, all rills were connected in a continuous transport system reaching the plot outlet, whilst on larger plots (10 and 20 m long) part of the rills ended with a deposition areas inside the plots. Amounts of erosion, calculated from rill volume and soil bulk density, were compared with soil loss measured at the plot outlets. On plots 10 and 20 m long, erosion estimated from volume of all rills was larger than measured soil loss. The latter was larger than erosion estimated from volume of contributing rills. To identify contributing soil loss area on these plots, two methods were applied: (i) ratio of total soil loss to maximum soil loss per unit area, and (

No abstract

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. Copyright © 2002 John Wiley & Sons, Ltd.

No abstract