The influence of tillage on N<sub>2</sub>O fluxes from an intensively managed grazed grassland in Scotland
Intensively managed grass production in high-rainfall temperate climate zones is a globally important source of N<sub>2</sub>O. Many of these grasslands are occasionally tilled to rejuvenate the sward, and this can lead to increased N<sub>2</sub>O emissions. This was investig...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-08-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/13/4811/2016/bg-13-4811-2016.pdf |
| Summary: | Intensively managed grass production in high-rainfall temperate climate zones
is a globally important source of N<sub>2</sub>O. Many of these grasslands are
occasionally tilled to rejuvenate the sward, and this can lead to increased
N<sub>2</sub>O emissions. This was investigated by comparing N<sub>2</sub>O fluxes from
two adjacent intensively managed grazed grasslands in Scotland, one of which
was tilled. A combination of eddy covariance, high-resolution dynamic chamber
and static chamber methods was used.
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N<sub>2</sub>O emissions from the tilled field increased significantly for several
days immediately after ploughing and remained elevated for approximately 2
months after the tillage event contributing to an estimated increase in
N<sub>2</sub>O fluxes of 0.85 ± 0.11 kg N<sub>2</sub>O-N ha<sup>−1</sup>. However, any
influence on N<sub>2</sub>O emissions after this period appears to be minimal. The
cumulative N<sub>2</sub>O emissions associated with the tillage event and a
fertiliser application of 70 kg N ammonia nitrate from one field were not
significantly different from the adjacent untilled field, in which two
fertiliser applications of 70 kg N ammonia nitrate occurred during the same
period. Total cumulative fluxes calculated for the tilled and untilled
fields over the entire 175-day measurement period were 2.14 ± 0.18 and
1.65 ± 1.02 kg N<sub>2</sub>O-N ha<sup>−1</sup>, respectively. |
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| ISSN: | 1726-4170 1726-4189 |