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Particulate organic matter predicts spatial variation in denitrification potential at the field scale.
- Source :
-
Geoderma . Aug2024, Vol. 448, pN.PAG-N.PAG. 1p. - Publication Year :
- 2024
-
Abstract
- High spatiotemporal variability in soil nitrous oxide (N 2 O) fluxes challenges quantification and prediction of emissions to evaluate the climate change mitigation outcomes of sustainable agricultural practices. Triggers for large, short-lived N 2 O emission pulses, such as rainfall and fertilization, alter soil oxygen (O 2) and nitrate (NO 3 –) availability to favor N 2 O production via denitrification. However, the organic C (OC) needed to fuel denitrification may exhibit subfield variation that constrains the potential for high denitrification rates to occur, leading to spatial variation in N 2 O hot moments. We tested the hypothesis that the particulate organic matter (POM) fraction of soil organic matter (SOM) controls subfield variation in denitrification potential by regulating availability of dissolved organic C (DOC), the form of OC used by denitrifiers. Among 38 soil samples collected across a maize field in central Illinois, USA, we found that potential denitrification rate was best predicted by POM C concentration (R2 = 0.35). Using multiple linear regression analysis that included other soil properties as explanatory variables, we found that POM C fraction of bulk soil (mg POM C/g SOC) was the most important predictor based on regression coefficient size (P < 0.01). Our results, which provide support for our hypothesis, suggest that consideration of the link between C and N cycling may be a key to predicting spatiotemporal variation in soil N 2 O emissions when denitrification is the dominant N 2 O source process. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00167061
- Volume :
- 448
- Database :
- Academic Search Index
- Journal :
- Geoderma
- Publication Type :
- Academic Journal
- Accession number :
- 178812037
- Full Text :
- https://doi.org/10.1016/j.geoderma.2024.116943