Aufklärung der Bodenverlagerung durch Bearbeitungserosion in Jungmoränenlandschaften

Abstract

Soil translocation caused by different soil erosion forms is one of the most important factor in the balance of matter and the increasing of soil landscape heterogeneity. The result is the typical pattern of soil landscapes in the Young Moraine regions of North-East Germany. The total soil translocation by water erosion and tillage erosion and the soil redistribution were investigated on 3 slopes characterised by topography as different catena types. The concentration of the tracer caesium-137 in soil profiles was compared with the concentration in reference profiles (permanent grass land). This allowed the calculation of sediment transport by water erosion and tillage erosion as well as the test of soil redistribution models. High caesium-137-contents (deposition) estimated on concave slope segments and depressed areas characterize sediment deposition and accumulation areas. Low caesium137-contents (erosion) estimated on convex upper slope positions and uniform straight slopes characterise soil loss areas. The different topography of the catena types was the determining factor for the kind of translocation. A relative low net soil loss was calculated for the catena typ I (catena with steep slopes and sandy soils). The relationship of the soil translocation due to tillage erosion and due to water erosion of about 7:1. The net soil loss calculated on the uniform straight slopes of the catena typ III (catena with low inclined slopes and loamy sandy soils) resulted in a predominantly soil translocation by water erosion (93 % of the total soil translocation). The relationship of the soil loss caused by tillage erosion and water erosion was about 1:13. To characterize the soil translocation by tillage operations with mouldboard plough, field cultivator and disk, the tools were tested in a field experiment. The used tracer were coloured gravels. The soil translocation was estimated by change of the tracer concentration after tillage operations. The translocated soil mass caused by mouldboard plough was 127 ± 39 kg m, by field cultivator 89 ± 27 kg m and by disc tools 15 ± 5kg m. The tillage transport coefficient k as a tillage erosion intensity parameter (a coefficient of tillage deepness, soil compaction, translocation distance and slope gradient) was significant higher for the cultivator operation