Journal article
C and N dynamics of a range of biogas slurries as a function of application rate and soil texture: a laboratory experiment



Publication Details
Authors:
Ludwig, B.; Sänger, A.; Geisseler, D.
Publisher:
TAYLOR & FRANCIS LTD
Publication year:
2014
Journal:
Archives of Agronomy and Soil Science
Pages range:
1779-1794
Volume number:
60
Issue number:
12
Start page:
1779
End page:
1794
Number of pages:
16
ISSN:
0365-0340

Abstract
Digestates vary in composition and studies regarding their impact on C and N dynamics in soils are scarce. The objective was to analyse the C and N dynamics of digestates originating from various substrates applied to a sandy Cambisol and a silty Anthrosol. In three laboratory experiments (4-6 weeks), the effects of digestate properties, N rate and water content were tested. Averaged over both soils, 21% of the C supplied was emitted as CO2. Potential NH3 emissions during the first week ranged between 6% and 12% of NH4+ present in the digestates. The emission factors in the sandy Cambisol were on average 1.2 and 2 times higher for CO2 and potential NH3, respectively, compared to the silty Anthrosol. Similarly, net nitrogen mineralization in the sandy Cambisol was approximately twice the N mineralized in the silty Anthrosol. Net nitrification was not influenced by soil texture or different digestates, but increased with increasing application rates and had highest values at 75% of water holding capacity. Our results indicate that the type of substrate input for anaerobic digestion influences the properties of the digestate and therefore the dynamics of C and N. However, soil texture can affect these dynamics markedly.


Keywords
CO2, NH3 volatilization, nitrification, N mineralization, soil texture


Authors/Editors

Last updated on 2019-25-07 at 19:34