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Land‐use related organic matter dynamics in North Cameroon soils assessed by 13 C analysis of soil organic matter fractions
Author(s) -
Sevink J.,
ObaleEbanga F.,
Meijer H. A. J.
Publication year - 2005
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/j.1365-2389.2004.00649.x
Subject(s) - organic matter , topsoil , soil water , soil organic matter , soil science , environmental science , total organic carbon , decomposition , environmental chemistry , δ13c , soil carbon , chemistry , stable isotope ratio , physics , quantum mechanics , organic chemistry
Summary Topsoil samples from cultivated and adjacent non‐cultivated fields on three major agricultural soils in North Cameroon were fractionated into particle‐size fractions that were analysed subsequently for their C and 13 C contents. The aim was to obtain further insight into the dynamics of soil organic matter (SOM) in relation to land use in Cameroon. Since organic carbon contents of the fractions were often very small, samples and analyses were extensively replicated to obtain robust statistical estimates of observed differences. For each soil type, differences in δ 13 C values between fields could be related to changes in the input and decomposition of organic matter arising from soil type, land management and, for example, the nature and abundance of weeds. Turnover of organic matter appeared to be fastest in the sand fraction, which is in line with results from earlier studies. In the finer fractions, clear differences in reaction to changes in input and decomposition were observed, that seem to be linked to differences in clay mineralogy. The results illustrate that SOM in the various fractions is much less stable and more strongly affected by changes in land use than might be assumed on the basis of changes in total SOM contents alone. At the same time, they demonstrate the relevance of 13 C isotope analyses of SOM for studies on the impact of land use on these savannah soils with little SOM that are highly susceptible to degradation.