Journal cover Journal topic
SOIL An interactive open-access journal of the European Geosciences Union
SOIL, 3, 161-176, 2017
https://doi.org/10.5194/soil-3-161-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Original research article
28 Sep 2017
Potential short-term losses of N2O and N2 from high concentrations of biogas digestate in arable soils
Sebastian Rainer Fiedler1, Jürgen Augustin2, Nicole Wrage-Mönnig1, Gerald Jurasinski1, Bertram Gusovius2, and Stephan Glatzel1,a 1Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, 18059, Germany
2Institute for Landscape Biogeochemistry, Leibniz Centre for Agriculture Landscape Research (ZALF) e.V., Müncheberg, 15374, Germany
anow at: Department of Geography and Regional Research, University of Vienna, Vienna, 1010, Austria
Abstract. Biogas digestate (BD) is increasingly used as organic fertilizer, but has a high potential for NH3 losses. Its proposed injection into soils as a countermeasure has been suggested to promote the generation of N2O, leading to a potential trade-off. Furthermore, the effect of high nutrient concentrations on N2 losses as they may appear after injection of BD into soil has not yet been evaluated. Hence, we performed an incubation experiment with soil cores in a helium–oxygen atmosphere to examine the influence of soil substrate (loamy sand, clayey silt), water-filled pore space (WFPS; 35, 55, 75 %) and application rate (0, 17.6 and 35.2 mL BD per soil core, 250 cm3) on the emission of N2O, N2 and CO2 after the usage of high loads of BD. To determine the potential capacity for gaseous losses, we applied anaerobic conditions by purging with helium for the last 24 h of incubation. Immediate N2O and N2 emissions as well as the N2 ∕ (N2O+N2) product ratio depended on soil type and increased with WFPS, indicating a crucial role of soil gas diffusivity for the formation and emission of nitrogenous gases in agricultural soils. However, emissions did not increase with the application rate of BD. This is probably due to an inhibitory effect of the high NH4+ content of BD on nitrification. Our results suggest a larger potential for N2O formation immediately following BD injection in the fine-textured clayey silt compared to the coarse loamy sand. By contrast, the loamy sand showed a higher potential for N2 production under anaerobic conditions. Our results suggest that short-term N losses of N2O and N2 after injection may be higher than probable losses of NH3 following surface application of BD.

Citation: Fiedler, S. R., Augustin, J., Wrage-Mönnig, N., Jurasinski, G., Gusovius, B., and Glatzel, S.: Potential short-term losses of N2O and N2 from high concentrations of biogas digestate in arable soils, SOIL, 3, 161-176, https://doi.org/10.5194/soil-3-161-2017, 2017.
Publications Copernicus
Download
Short summary
Injection of biogas digestates (BDs) is suspected to increase losses of N2O and thus to counterbalance prevented NH3 emissions. We determined N2O and N2 losses after mixing high concentrations of BD into two soils by an incubation under an artificial helium–oxygen atmosphere. Emissions did not increase with the application rate of BD, probably due to an inhibitory effect of the high NH4+ content in BD on nitrification. However, cumulated gaseous N losses may effectively offset NH3 reductions.
Injection of biogas digestates (BDs) is suspected to increase losses of N2O and thus to...
Share