Format:
Online-Ressource
ISSN:
1522-2624
Content:
Abstract: Site conditions and soil management determine the content and the composition of soil organic matter (SOM). Organic matter (OM) is characterized by functional groups, which preferentially interact with polyvalent cations and soil minerals. These interactions could perhaps explain the site‐specific composition of bulk SOM and a pyrophosphate‐soluble OM fraction (OM‐PY) using basic soil properties. The objective of this study was to test a simplified model for the interactions between OM and polyvalent cations (i.e., Ca, Mg, Al, Fe, and Mn) by using data from soils from long‐term field experiments. The model considered (1) OM–cation, (2) OM–cation‐mineral, and (3) OM–mineral associations and assumed that the availability of the cation's coordination sites for the interaction with OM depends on these three types of associations. The test was carried out using data (topsoil) from differently fertilized plots from three long‐term field experiments (Halle, Bad Lauchstädt, Rotthalmünster). The composition of SOM and OM‐PY was characterized by the relationship of the ratio of the C=O (i.e., here indicating both carbonylic and carboxylic groups) versus C–O–C absorption band intensities obtained from the Fourier transform infrared (FTIR) spectra with the content of exchangeable, oxalate‐, and dithionite‐extractable polyvalent cations. The assumed associations between the OM and cations and the availability of the coordination sites explained most of the variations in the C=O/C–O–C ratios of the SOM, and fewer variations in the OM‐PY, when using the site‐specific exchangeable and oxalate‐extractable cation contents. The C=O/C–O–C ratios of the OM‐PY were site‐independent for samples from plots that regularly received farmyard manure. The results suggested that a simplified model that considers the polyvalent cation content weighted by the number of coordination sites per cation according to the type of association could be used to improve the explanation of site‐specific differences in the OM composition of arable soils.
In:
volume:181
In:
number:5
In:
year:2018
In:
pages:721-736
In:
extent:16
In:
Journal of plant nutrition and soil science, Weinheim : Wiley-VCH, 1922-, 181, Heft 5 (2018), 721-736 (gesamt 16), 1522-2624
Language:
English
DOI:
10.1002/jpln.201800093
URN:
urn:nbn:de:101:1-2022090211543052918572
URL:
https://doi.org/10.1002/jpln.201800093
URL:
https://nbn-resolving.org/urn:nbn:de:101:1-2022090211543052918572
URL:
https://d-nb.info/126702447X/34
URL:
https://doi.org/10.1002/jpln.201800093
