Keywords
greenhouse gases, paddy-rice, validation, simulation, brazil
Start Date
1-7-2010 12:00 AM
Abstract
Agricultural activities have been pointed out as one of anthropogenic sources of greenhouse gas emissions, which influence on climatic changes. Information available at Intergovernmental Panel on Climatic Changes (Ipcc) indicated that methane emissions (CH4) generated during the paddy-rice culture development phases is one of these activities and must be better investigated at field conditions. Computer tools that allow following the space-time dynamic of methane emissions from paddy-rice culture, considering the management involved, should also contribute to identify alternatives in order to minimize the high emission rates. Thereby, the Denitrification-Decomposition model (DnDc) can be used to investigate alternative scenarios in order to understand the paddy-rice methane emission process and to identify the critical points. However, DnDc validation is necessary to assure the reliability of those scenarios. Paddy-rice data collected during the seasons of 2004/2005 and 2005/2006 at Pindamonhangaba municipality, São Paulo State – Brazil, from Agrogases and Carboagro Projects, made possible to compare the quantified seasonal methane emissions from field with those estimated by the DnDc (version 8.9) scenarios. The DnDc/quantified seasonal methane emission rates reached were 0.99 for 2004/2005 and 0.70 for 2005/2006. On average, DnDc estimated the methane emissions 84.6 ± 14.6% close to those quantified from field.
Estimates of Seasonal Methane Emissions from Paddy-Rice Cropped at Pindamonhangaba Municipality, Brazil, Using DnDc Model
Agricultural activities have been pointed out as one of anthropogenic sources of greenhouse gas emissions, which influence on climatic changes. Information available at Intergovernmental Panel on Climatic Changes (Ipcc) indicated that methane emissions (CH4) generated during the paddy-rice culture development phases is one of these activities and must be better investigated at field conditions. Computer tools that allow following the space-time dynamic of methane emissions from paddy-rice culture, considering the management involved, should also contribute to identify alternatives in order to minimize the high emission rates. Thereby, the Denitrification-Decomposition model (DnDc) can be used to investigate alternative scenarios in order to understand the paddy-rice methane emission process and to identify the critical points. However, DnDc validation is necessary to assure the reliability of those scenarios. Paddy-rice data collected during the seasons of 2004/2005 and 2005/2006 at Pindamonhangaba municipality, São Paulo State – Brazil, from Agrogases and Carboagro Projects, made possible to compare the quantified seasonal methane emissions from field with those estimated by the DnDc (version 8.9) scenarios. The DnDc/quantified seasonal methane emission rates reached were 0.99 for 2004/2005 and 0.70 for 2005/2006. On average, DnDc estimated the methane emissions 84.6 ± 14.6% close to those quantified from field.
