ABSTRACT The DayCent ecosystem model, widely tested in upland agroecosystems, was recently updated to simulate waterlogged soils. We evaluated the new version in a paddy rice experiment in Southern Brazil. DayCent was used to simulate rice yield, soil organic carbon (SOC), and soil CH4 fluxes. Model calibration was conducted with a multiple-year dataset from the conventional tillage treatment, followed by a validation phase with data from the no-tillage treatment. Model performance was assessed with statistics commonly used in modeling studies: […]

On paddy soils in the southern region of the State of Rio Grande do Sul, Brazil, irrigated (flooded) rice is grown on 1´000´000 ha, under different soil management systems. The influence of poor drainage and alternating oxidation and reduction cycles on the content of soil organic carbon is still poorly understood. This long-term study (21 years) was conducted in Capão do Leão, RS, Brazil, to evaluate the effect of irrigated rice management systems on soil organic carbon stocks and physical […]