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“Hot spots” of N and C impact nitric oxide, nitrous oxide and nitrogen gas emissions from a UK grassland soil.
- Source :
-
Geoderma . Nov2017, Vol. 305, p336-345. 10p. - Publication Year :
- 2017
-
Abstract
- Agricultural soils are a major source of nitric- (NO) and nitrous oxide (N 2 O), which are produced and consumed by biotic and abiotic soil processes. The dominant sources of NO and N 2 O are microbial nitrification and denitrification, and emissions of NO and N 2 O generally increase after fertiliser application. The present study investigated the impact of N-source distribution on emissions of NO and N 2 O from soil and the significance of denitrification, rather than nitrification, as a source of NO emissions. To eliminate spatial variability and changing environmental factors which impact processes and results, the experiment was conducted under highly controlled conditions. A laboratory incubation system (DENIS) was used, allowing simultaneous measurement of three N-gases (NO, N 2 O, N 2 ) emitted from a repacked soil core, which was combined with 15 N-enrichment isotopic techniques to determine the source of N emissions. It was found that the areal distribution of N and C significantly affected the quantity and timing of gaseous emissions and 15 N-analysis showed that N 2 O emissions resulted almost exclusively from the added amendments. Localised higher concentrations, so-called hot spots, resulted in a delay in N 2 O and N 2 emissions causing a longer residence time of the applied N-source in the soil, therefore minimising NO emissions while at the same time being potentially advantageous for plant-uptake of nutrients. If such effects are also observed for a wider range of soils and conditions, then this will have major implications for fertiliser application protocols to minimise gaseous N emissions while maintaining fertilisation efficiency. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00167061
- Volume :
- 305
- Database :
- Academic Search Index
- Journal :
- Geoderma
- Publication Type :
- Academic Journal
- Accession number :
- 124403619
- Full Text :
- https://doi.org/10.1016/j.geoderma.2017.06.007