Evaluation of the capacity of the IPCC Tool to estimate soil organic carbon changes in pampean soils

G BERHONGARAY; R ALVAREZ

Congreso; XXIII Congreso Argentino de la Ciencia del Suelo; 2012

The Intergovernmental Panel on Climate Change (IPCC) has developed a model to estimate soil organic carbon (SOC) stocks around the World, known as the IPCC Tool (IPCC 2003). The present study evaluated the capacity of the IPCC Tool to estimate SOC stocks and  changes in soils of the Pampean Region of Argentina. We evaluated this capacity by comparing the IPCC Tool estimations with data from a detailed soil survey carried out in 2007-2008 on 82 farms. We sampled uncropped fields, as well as agricultural soils under the crop or the pasture phase of a mixed rotation. Using the default parameters, the IPCC Tool did not estimate SOC stocks of uncropped fields with an acceptable performance (R2= 0,2 RMSE= 27,7 t ha-1ponelo en %). On average, the IPCC Tool estimated SOC decreases by cultivation of 34%, but measured SOC changes were 14% under the cropping phase and 10% under the pasture phase of the rotations. For an  acceptable  performance of the IPCC Tool the default values, the grouping criteria, and the land use factors should be changed using local data for calibration.