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Abstract

Soil organicmatter (SOM) content and compositionmay be affected by geographic region, land use (grassland vs. forest) and management intensity (intensive vs. extensive). To asses these effects SOM of 300 German soils was characterized using soil color analyses (L*,a*,b*-values) and Fourier transform infrared (FTIR) spectroscopy. Soil lightness (L*-value)was strongly negatively correlatedwith the soil organic carbon content and this relationship was stronger when the previously sieved soils were ground. Using the band at wavenumber 1634 cm−1 (as determined by FTIR) as a proxy for aromaticity of SOM the L*-value was negatively correlated with aromaticity. Geographic region as well as land use affected L*-, a*- and b*-values. FTIR results suggested that particularly amides and polysaccharideswere affected by geographic region,whilemainly polysaccharideswere affected by land use.Weconclude that soil color analysis can provide additional information on environmental circumstances/site effects which may affect SOM composition. A few only weak correlations of soil color/SOM composition parameters withmanagement intensity indicate that either changes in SOMparameters were too small or that the applied management indices were not sensitive enough to management effects.