Koestel, Johannes
- Department of Soil and Environment, Swedish University of Agricultural Sciences
Abstract
While renewable biofuels can reduce negative effects of fossil fuel energy consumption, the magnitude of their benefits depends on the magnitude of N2O emissions. High variability of N2O emissions overpowers efforts to curb uncertainties in estimating N2O fluxes from biofuel systems. In this study, we explored (a) N2O production via bacterial denitrification and (b) N2O emissions from soils under several contrasting bioenergy cropping systems, with specific focus on explaining N2O variations by accounting for soil pore characteristics. Intact soil samples were collected after 9years of implementing five biofuel systems: continuous corn with and without winter cover crop, monoculture switchgrass, poplars, and early-successional vegetation. After incubation, N2O emissions were measured and bacterial denitrification was determined based on the site-preference method. Soil pore characteristics were quantified using X-ray computed microtomography. Three bioenergy systems with low plant diversity, that is, corn and switchgrass systems, had low porosities, low organic carbon contents, and large volumes of poorly aerated soil. In these systems, greater volumes of poorly aerated soil were associated with greater bacterial denitrification, which in turn was associated with greater N2O emissions (R-2=0.52, p
Keywords
bacterial denitrification; computed microtomography; particulate organic matter; plant diversity; site-preference analysis; soil pore size distributions
Published in
GCB Bioenergy
2018, volume: 10, number: 11, pages: 894-909
Publisher: WILEY
SLU Authors
Global goals (SDG)
SDG7 Affordable and clean energy
SDG12 Responsible consumption and production
UKÄ Subject classification
Soil Science
Bioenergy
Publication identifier
- DOI: https://doi.org/10.1111/gcbb.12552
Permanent link to this page (URI)
https://res.slu.se/id/publ/96876