CIMA   09099
CENTRO DE INVESTIGACIONES DEL MAR Y LA ATMOSFERA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Global warming and wheat production in Argentina.
Autor/es:
MAGRIN G.; TRAVASSO, M.I; RODRÍGUEZ G; SOLMAN S; NÚÑEZ M
Lugar:
Estambul, Turquía
Reunión:
Conferencia; Global Conference on Global Warming; 2008
Institución organizadora:
University of Ontario
Resumen:
Argentina in an important wheat producer and highly contributes to global exportations. The
main planted area is located in the Pampas region, where the crop is developed under rainfed
conditions. In the last decade, the area devoted to wheat ranged between 4.9 and 7.3 millions of
hectares, mean yield attained 1,900-2,600 kg/ha, and countrys production varied between 9.4
and 16 millions of tons (Mt). The internal consumption is near to 6 Mt, and remainder production
is exported, transforming the country in the fifth worlds exporter with a key role in food
security. Changes observed in precipitation and temperatures increases during the last three
decades had changed crops productivity in the Pampas. This is a crucial issue not only for the
significant role of commodities in the Argentinas economy, but also for its potential impact on
world food security.
The aim of this work was to assess the impact of past and future changes in climate on potential
wheat productivity. The study was based on long term daily climatic data (since 1930) and crop
productivity, regional climatic scenarios based on the down scaling of HadCM3 GCM
(MM5/CIMA), and a crop simulation model (DSSAT v4.0).
In the central and northern part of the Pampas, potential wheat yield has been decreasing with
increasing rates since 1930 (28.3 kg/ha between 1930-2000, and 52.7 kg/ha between 1970-2000)
due mainly to winter and spring warming. Further increases in temperature could lead to wheat
yield reductions of 7.5% for each °C of temperature raise until 3°C.
According to MM5/CIMA climatic projections, in 2080 under the SRES A2 scenario,
temperature will raise between 2°C and 3°C and spring- summer precipitations will have slight
increases. Under these conditions mean wheat yield will be reduced by 4% with a great spatial
variability. The zones more affected will be those located in the north (Nor-west of Buenos Aires
province, and parts of Santa Fe and Cordoba with decreases between 20% and 30%), while the
south-west portion could be benefited with increases near to 20% . If CO2 effects are considered
mean wheat yield could increase by 14% in the Pampas. However in isolated sites, located
mainly in the central and northern part, yields could decrease up to 10% despite CO2 effects.
In the future should be convenient to advance planting dates for taking advantage of the new
environmental conditions where frost free periods would be prolonged.