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| Titel |
The effect of alternate wetting and drying on methane fluxes on different
varieties of European rice |
| VerfasserIn |
Viktoria Oliver, Nicole Cochrane, Stefano Monaco, Andrea Volante, Gabriele Orasen, Adam Price, Yit Arn Teh |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250154531
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| Publikation (Nr.) |
 EGU/EGU2017-19640.pdf |
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| Zusammenfassung |
| In Europe, rice is grown (467 000 ha) under permanently flooded conditions (PF) using
irrigation waters of major rivers. Climate change, which has led to a greater fluctuation in
river flows, is a major challenge to rice production systems, which depend on large and
consistent water supplies. This challenge will become more acute in the future,
with more frequent extreme weather (e.g. drought) predicted under climate change
and increased demands for rice. Alternate wetting and drying (AWD) is a system
in where irrigation is applied to obtain 2-5 cm of field water depth, after which
the soil is allowed to drain naturally to typically 15 cm below the surface before
re-wetting once more. Preliminary studies suggest that AWD can reduce water use
by up 30 %, with no net loss in yield but significantly reducing CH4 emissions.
The work presented here evaluated the impacts of AWD on the productivity and
yield of twelve varieties of European rice, whilst simultaneously measuring CH4
fluxes and plant biomass allocation patterns under different treatment regimes.
Field experiments were conducted in the Piedmont region (northern Italy Po river
plain) in a loamy soil during the growing season of 2015 in a 2-factor paired plot
design, with water treatment (AWD, PF) and variety (12 European varieties) as
factors (n=4 per variety per treatment). The varieties chosen were commercially
important cultivars from across the rice growing regions of Europe (6 Italian, 3
French, 3 Spanish). Greenhouse gas fluxes were taken using the static chamber
approach 11 times during the growing season between May and October 2015.
Environmental variables (soil moisture, temperature, water table depth, water potential) were
collected concomitantly. Above and belowground biomass were determined by
destructively harvesting at the end of the growing season. Belowground biomass was
estimated by manually extracting roots from 30 cm deep soil cores and aboveground
biomass estimated by collecting and weighing the rachis, grain and straw on a 1 metre
linear section from every variety of rice. Overall, there was no significant effect
between AWD and PF systems on rough grain production (863 and 822 g DM
m−2) or straw yield (776 and 813 g DM m−2) for PF and AWD, respectively. The
alternate wetting and drying sites had significantly lower CH4 fluxes 0.197 ± 0.066
compared to the permanently flooded 0.557 ± 0.090 g C m−2 d−1, with Baldo
(Italian) producing the highest emissions. Overall there was ∼ 40 % water saving. The
results from this study highlight that this novel water management strategy for
European rice can have multiple environmental benefits without sacrificing yield. |
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