Open AccessDecomposability of recalcitrant soil carbon assessed by denitrification
Author(s) -
Christensen Søren
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb04818.x
Subject(s) - denitrification , mineralization (soil science) , soil water , chemistry , soil respiration , beech , agronomy , nitrate , environmental chemistry , soil biology , environmental science , nitrogen , soil science , botany , biology , organic chemistry
The decomposability of carbon compounds remaining in soil after decomposition during extended storage was studied by measuring denitrification in anaerobic soil slurries. The denitrification assay is not disturbed by heterogenous conditions of incubation and employs a physiologically rather homogenous group of respiring organisms. In five soils (alder, elm, meadow, barley and grass) all C mineralization occurred by oxidation and denitrification was the dominant process when NO 3 − was added. In beech soil, fermentation prevailed and the amount of C oxidized doubled when NO 3 − was added. The quality of soil C for respiration was low and surprisingly similar in soils from alder, beech and grass corresponding to 0.3 mg C g −1 soil C d −1 . In meadow, barley and elm the quality of soil C for respiration was 2–3 times higher. The separation of the six soils based on C quality for denitrification was parallel to soil characteristics such as freeze/thaw effects and nutrient release from soil C and site characteristics such as earthworm biomass and plant cover.