Die flächenhafte Variabilität bodenphysikalischer Parameter und des Corg-Gehaltes in den Pflugsohlen je eines Ton-, Sand- und Lößstandortes

Spatial variability of soil physical properties in the plow pans each of one clay, sand, and loess site Total porosity (PV), amount of micropores (< 0,2 μm; fPV) and macropores (> 10 μm; gPV) on total porosity, plant available water (nFK) and organic carbon (C_org) were measured at regular grids in the plow pans of a clay, a sand and a loess field. The variation of total porosity was remarkably low in each field (coefficient of variation v = 5.9% - 11.9%). Means of PV can therefore be estimated with a sample density of 2 per ha (1 ha = 10⁴ m²) to achieve a standard error Δa lower than 10%. More samples are needed to estimate fPV, gPV, nFK and C_org with a corresponding standard error on the clay and on the sand field (10–20 samples/ha). Comparison of block-kriging with a classical interpolation method showed that geostatistics should be applied to obtain realistic maps of the spatial distribution of soil physical properties.