Properties and composition of soil organic matter in forest and arable soils of Schleswig‐Holstein: 1. Comparison of morphology and results of wet chemistry, CPMAS‐¹³C‐NMR spectroscopy and pyrolysis‐field ionization mass spectrometry

Abstract

Abstract Properties and composition of 25 soil samples (0.8–51% C org ) were determined by morphology, wet chemistry, CPMAS‐ 13 C‐NMR‐spectroscopy and pyrolysis‐field ionization mass spectrometry (Py‐FIMS). The recovery rate of organic carbon was 102% (±15%). The correlation between the litter compound/humic compound ratio and humification grade, estimated with morphological observations, was strong (r 2 = 0.502 *** ). A typical classification of horizons (L, O, H, Ah+M) with regard to organic compounds (wet chemistry and 13 C‐NMR) was not always significant. The pyrolysis‐mass spectra confirmed and extended on the basis of molecular chemical structures the results of wet chemistry, especially with polysaccharides, nitrogen compounds, lignin, lipids and alkylaromatics (r 2 = 0.818–0.937 *** ). A correlation between the NMR‐aliphatics, the humic compounds isolated by wet chemistry, and the long‐chain aliphatic carbon units in the pyrolysis‐mass spectra was established.