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| Titel |
Effect of nitrification inhibitors (DMPP and 3MP+TZ) on soil nitrous oxide emissions from a sub-tropical vegetable production system in Queensland, Australia |
| VerfasserIn |
Clemens Scheer, Peter Deuter, Mary Firrell, David Rowlings, Peter Grace |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102367
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| Publikation (Nr.) |
 EGU/EGU2015-1681.pdf |
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| Zusammenfassung |
| The use of nitrification inhibitors, in combination with ammonium based fertilisers, has been
promoted recently as an effective method to reduce nitrous oxide (N2O) emissions from
fertilised agricultural fields, whilst increasing yield and nitrogen use efficiency. Vegetable
cropping systems are often characterised by high inputs of nitrogen fertiliser and
consequently elevated emissions of nitrous oxide (N2O) can be expected. However, to date
only limited data is available on the use of nitrification inhibitors in sub-tropical vegetable
systems. A field experiment investigated the effect of the nitrification inhibitors (DMPP &
3MP+TZ) on N2O emissions and yield from a typical vegetable production system
in sub-tropical Australia. Soil N2O fluxes were monitored continuously over an
entire year with a fully automated system. Measurements were taken from three
subplots for each treatment within a randomized complete blocks design. There
was a significant inhibition effect of DMPP and 3MP+TZ on N2O emissions and
soil mineral N content directly following the application of the fertiliser over the
vegetable cropping phase. However this mitigation was offset by elevated N2O
emissions from the inhibitor treatments over the post-harvest fallow period. Cumulative
annual N2O emissions amounted to 1.22 kg-N/ha, 1.16 kg-N/ha, 1.50 kg-N/ha
and 0.86 kg-N/ha in the conventional fertiliser (CONV), the DMPP treatment, the
3MP+TZ treatment and the zero fertiliser (0N) respectively. Corresponding fertiliser
induced emission factors (EFs) were low with only 0.09 - 0.20% of the total applied
fertiliser lost as N2O. There was no significant effect of the nitrification inhibitors on
yield compared to the CONV treatment for the three vegetable crops (green beans,
broccoli, lettuce) grown over the experimental period. This study highlights that
N2O emissions from such vegetable cropping system are primarily controlled by
post-harvest emissions following the incorporation of vegetable crop residues into the
soil. It also shows that the use of nitrification inhibitors can lead to elevated N2O
emissions by storing N in the soil profile that is available to soil microbes during the
decomposition of the vegetable residues over the post-harvest phase. Hence the use of
nitrification inhibitors in vegetable systems has to be treated carefully and fertiliser
rates need to be adjusted to avoid excess soil nitrogen during the postharvest phase. |
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