Soil organic matter composition in urbic anthrosols in the city of Kiel, NW-Germany, as revealed by wet chemistry and CPMAS 13C-NMR spectroscopy of whole soil samples

Abstract

In urban environment soil organic matter (SOM) has manifold functions and a tremendous ecological significance. However, little is known about SOM in urbic soils. In six top layers of soils with different age in the city of Kiel at the Baltic Sea, Northwest Germany, the SOM composition was investigated by means of wet chemistry and CPMAS ¹³C—NMR spectroscopy and compared to data of natural soils. In the urbic forest soils a low level of the recalcitrant lipid fraction and of the mobile fulvic acid fraction and the high amount of carboxylic units in the humic compounds did not reflect the SOM pattern of natural, acidic forests soils. In peaty soils probably a high heavy metal contamination does not retard litter decomposition. A very high aromaticity of total SOM and of the humic compounds might be typical for soils under horticulture in private gardens. In the young soils litter compounds dominate in the SOM. NMR data suggest, that the extracted humic fractions were chemically ill-defined moieties.