Comparison of soil and sediment properties of a loamy sand soil

Ten 25 m(2) runoff plots at the Hilton experimental site, east Shropshire, UK, have been used to compare the physicochemical properties of loamy sand plot soils and sediment eroded from the plots over one year. Sediment contained more sand (2 mm-60 mu m) and less clay (< 2 mu m), silt (2-60 mu m) and coarse fraction (> 2 mm) than soil. Erosion rates increased with slope and proportionally more silt and particularly clay were eroded on steeper slopes. Selective clay depletion has serious implications for soil structure and fertility. Correlations existed between the organic matter contents and particle size distributions of soil and sediment, but the sediment had less organic matter and lower pH values than soil, Sediment also contained lower concentrations of calcium, iron, potassium, magnesium, manganese and phosphorus than soil. Relationships between erosion and soil textural change appear to be partly technique-dependent, which suggests more uniformity in approach would be beneficial in studies on the effects of erosion on soil fertility.