Influence of shelter on soil sorting by wind erosion — a case study

Abstract

Textural analyses were conducted in order to quantify the soil status in two nearby fields with 80 m and 200 m spacing of shelter hedges. Surface soil samples in the more wind exposed field show a significantly ( P < 0.001) lower content (approximately 8%) of silt + clay particles (< 0.063 mm) compared to the more sheltered field. A different intensity of wind erosion between the fields over a period of approximately 45 years (since shelter hedges in the area were high enough to act as windbreaks) is stipulated to account for the difference in soil composition. Also, in samples taken at a depth of 0–25 cm, a lower proportion (approximately 4%) of silt + clay material is observed. Here the difference is explained by ploughing of the wind eroded surface, causing a recurring downward transport of remaining coarser particles. Soil samples collected in 1988 and 1990 indicate that the progression toward a coarser soil texture is not linear, but rather fluctuates between the seasons owing to a varying wind climate, crop cover and soil conditions. Whereas no spatial pattern was apparent in the wind-exposed field, samples taken from the sheltered field showed a lower content of fine particles both at the surface and at 0–25 cm beneath the surface in the central and southeastern parts. This indicates that these parts have been most exposed to wind erosion, which is consistent with the orientation of the shelter hedges and the dominating wind erosion directions.