Dissertação
Validação do modelo Agro-ibis para um sítio experimental de soja no Rio Grande do Sul
Fecha
2011-03-24Registro en:
WEBLER, Geovane. Agro-IBIS MODEL VALIDATION AT A SOYBEAN EXPERIMENTAL
SITE IN RIO GRANDE DO SUL. 2011. 60 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Santa Maria, Santa Maria, 2011.
Autor
Webler, Geovane
Institución
Resumen
The Agro-IBIS model is validated for a soybean experimental site in the state of Rio Grande
do Sul. This experiment is conducted in order to evaluate the impact of different soil
management systems on different areas of science. In the site, we obtained
micrometeorological measures of energy, mass and water exchanges between the soybean
ecosystem and the environment during the 2009/2010 soybean growing season. We used two
management systems: (1) no-tillage system (NT) and (2) conventional tillage system (CT).
The model was forced with meteorological data from the Brazilian National Institute of
Meteorology (INMET). The results of the model were compared with the observed data in
order to evaluate the capacity of the model in simulating the interaction of the soybean
ecosystem with environment and also to verify the effects of surface coverage by crop
residues in NT. Since the model does not have the representation of crop residues, i.e., of NT,
its effects are not expected in the simulation results. The results indicate that the model
simulates the radiative balance and flows of energy in a satisfactory way. Besides this, soil
moisture in the 0-20 cm and 20-50 cm layers and the 0-50 cm integration as well as soil
temperature at 2 cm are simulated in a suitable way. For soil moisture, the simulated results
represent better the observed data in CT, indicating that the effect of soil coverage by crop
residues is not simulated. In the variables related to CO2, the model has problems concerning
the simulation of the ecosystem respiration, which is strongly underestimated. This leads to an
inconsistency in the simulation of the others variable related to CO2, mainly of those which
consider the night-time data, since at night the net CO2 exchange of the ecosystem (NEE) is
the respiration. For the daytime CO2 the model shows good performance, except in the period
of leaf senescence, when the model indicates CO2 uptake by the ecosystem and the
experimental data indicate emission.