Publications (FIS)

Greenhouse Gas Balance of Sphagnum Farming on Highly Decomposed Peat at Former Peat Extraction Sites

authored by: Jan Oestmann, Bärbel Tiemeyer, Dominik Düvel, Amanda Grobe, Ullrich Dettmann
Abstract: For two years, we quantified the exchange of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) at two different large-scale Sphagnum farming sites. At both, peat extraction left a shallow layer of highly decomposed peat and low hydraulic conductivities. One site was characterized by preceding multi-annual inundation and irrigated by ditches, while the other one was inoculated directly after peat extraction and irrigated by ditches and drip irrigation. Further, GHG emissions from an irrigation polder and the effect of harvesting Sphagnum donor material at a near-natural reference site were determined. GHG mitigation potentials lag behind the results of less decomposed sites, although our results were also affected by the extraordinary hot and dry summer 2018. CO₂ exchanges ranged between -0.6 and 2.2 t CO₂-C ha⁻¹ y⁻¹ and were mainly influenced by low water table depths. CH₄ emissions were low with the exception of plots with higher Eriophorum covers, while fluctuating water tables and poorly developing plant covers led to considerable N₂O emissions at the ditch irrigation site. The removal of the upper vegetation at the near-natural site resulted in increased CH₄ emissions and, on average, lowered CO₂ emissions. Overall, best plant growth and lowest GHG emissions were measured at the previously inundated site. At the other site, drip irrigation provided more favourable conditions than ditch irrigation. The size of the area needed for water management (ditches, polders) strongly affected the areal GHG balances. We conclude that Sphagnum farming on highly decomposed peat is possible but requires elaborate water management.
Organisation(s): Institute of Environmental Planning
Section Soil Chemistry
Institute of Soil Science
External Organisation(s): Johann Heinrich von Thünen Institute, Federal Research Institute for Rural Areas, Forestry and Fisheries
Type: Article
Journal: ECOSYSTEMS
Volume: 25
Pages: 350-371
No. of pages: 22
ISSN: 1432-9840
Publication date: 03.2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Ecology, Evolution, Behavior and Systematics, Environmental Chemistry, Ecology
Electronic version(s): https://doi.org/10.1007/s10021-021-00659-z (Access: Open)

BibTeX

@article{2836f5f9a0c0420488d601aa295506fa,
title = "Greenhouse Gas Balance of Sphagnum Farming on Highly Decomposed Peat at Former Peat Extraction Sites",
abstract = "For two years, we quantified the exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) at two different large-scale Sphagnum farming sites. At both, peat extraction left a shallow layer of highly decomposed peat and low hydraulic conductivities. One site was characterized by preceding multi-annual inundation and irrigated by ditches, while the other one was inoculated directly after peat extraction and irrigated by ditches and drip irrigation. Further, GHG emissions from an irrigation polder and the effect of harvesting Sphagnum donor material at a near-natural reference site were determined. GHG mitigation potentials lag behind the results of less decomposed sites, although our results were also affected by the extraordinary hot and dry summer 2018. CO2 exchanges ranged between -0.6 and 2.2 t CO2-C ha−1 y−1 and were mainly influenced by low water table depths. CH4 emissions were low with the exception of plots with higher Eriophorum covers, while fluctuating water tables and poorly developing plant covers led to considerable N2O emissions at the ditch irrigation site. The removal of the upper vegetation at the near-natural site resulted in increased CH4 emissions and, on average, lowered CO2 emissions. Overall, best plant growth and lowest GHG emissions were measured at the previously inundated site. At the other site, drip irrigation provided more favourable conditions than ditch irrigation. The size of the area needed for water management (ditches, polders) strongly affected the areal GHG balances. We conclude that Sphagnum farming on highly decomposed peat is possible but requires elaborate water management.",
author = "Jan Oestmann and B{\"a}rbel Tiemeyer and Dominik D{\"u}vel and Amanda Grobe and Ullrich Dettmann",
note = "Funding Information: This research was funded by the Lower Saxony Ministry for Nutrition, Agriculture and Consumer Protection (ML, AZ 105.1-3234/1-13-3) and the German Federal Environmental Foundation (DBU, AZ 33305/01-33/0). The permissions granted by the Weser-Ems Office for Regional State Development (State Bog Administration) and the County Emsland have facilitated the project. We thank our project partners at Klasmann-Deilmann GmbH for the productive cooperation. We gratefully thank two anonymous reviewers for their knowledgeable and constructive comments. We also want to express our thanks to Kerstin Gilke and Andrea Oehns-Rittgerodt for gas chromatograph analyses; Sabine Wathsack, Ute Tambor, Thomas Viohl and Claudia Wiese for water, soil and biomass analysis, Frank Hegewald and Dirk Lempio for technical assistance in the field, and Arndt Piayda for data on hydraulic conductivity and soil sampling together with Mareille Wittnebel. Finally, we would also like to thank the students who helped in the field and in the laboratory. ",
year = "2022",
month = mar,
doi = "10.1007/s10021-021-00659-z",
language = "English",
volume = "25",
pages = "350--371",
journal = "ECOSYSTEMS",
issn = "1432-9840",
publisher = "Springer New York",
number = "2",
}