Short-term soil mineral and organic nitrogen fluxes during moderate and severe drying-rewetting events
- Author(s)
- Sonja Leitner, Pia Minixhofer, Erich Inselsbacher, Katharina M. Keiblinger, Michael Zimmermann, Sophie Zechmeister-Boltenstern
- Abstract
Nitrogen (N) availability to plants in dry soil is limited by diffusive flux of N compounds through the soil solution towards the root surface. Conventional soil extraction procedures only provide information about bulk soil N concentrations, which can be distorted during soil sampling, transport, storage and extraction, and hence are of limited use to detect short-term N dynamics. Soil microdialysis is a new tool to monitor diffusive flux of mineral and organic N compounds in situ in high temporal and spatial resolution with minimal disturbance, and is therefore well-suited to determine dynamic fractions of plant-available N in soil microsites. We investigated N availability and mobilization during a drying–rewetting event in a temperate beech forest using soil microdialysis and soil extractions with water. While water extracts mainly revealed mineral N in the form of NH
4
+ and NO
3
−, diffusive N fluxes in situ were dominated by amino acids. Microdialysis showed that rewetting of dry soil led to a fast but short-lived mobilization of NO
3
− and some neutral hydrophilic amino acids (lysine, glutamine, cysteine, glycine), which was not detected in water extracts, and the rewetting N flush was larger with increasing drought duration. Our results suggest that at our temperate forest site plant-available N was dominated by amino acids, a fraction of N that might be missed using conventional soil extraction methods. Considering expected increases in the frequency of extreme climatic events, the observed release of mobile N forms bears the potential of N loss from soil if severe drought is followed by a heavy rain event.
- Organisation(s)
- Department of Geography and Regional Research
- External organisation(s)
- University of Natural Resources and Life Sciences
- Journal
- Applied Soil Ecology
- Volume
- 114
- Pages
- 28-33
- No. of pages
- 6
- ISSN
- 0929-1393
- DOI
- https://doi.org/10.1016/j.apsoil.2017.02.014
- Publication date
- 06-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 106030 Plant ecology, 401208 Forest ecology, 401901 Soil erosion
- Keywords
- ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous), Soil Science, Ecology
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/48e61ff5-a4e7-473d-b5fd-053f1784795c