Aplicación de Sistemas de Información Geográfica para la Delimitación de Áreascon Diferente Capacidad de Adsorción de Atrazina

Abstract

The spatial variability of atrazine (2-chloro-a-ethylamino-6-isopropylamino-s-triazine) sorption in soils of the province of Córdoba (Argentina) was evaluated by the distribution coefficient, Kd (L kg-1). The Kd was estimated based on the model proposed by Weber et al. (2004). The edaphic attributes considered were soil organic matter (SOM), clay content (ARC) and pH. This information was recovered from the soil surveys of the province of Córdoba and digital soil maps of GeoINTA. Validation of the Weber model KdW (L kg-1) = 4.1 + 0.43 MOS (%) + 0.09 ARC (%) – 0.81 pH, was performed with 46 Kd (L kg- 1). The range of estimated Kd (Kdw) was between negative KdW and 4.42 L kg-1 from a collection of different studies in the Argentinean Pampas. Eighty eight o 88 percent of the estimated values ranged from 0.5 to 2.9 L kg-1. The distribution of the Kdw values was 47.7% lower than 1.5 L kg-1; 40.3% between 1.5 and 2.5 kg L-1, and 12% greater than 2,5 L kg-1. By interpolation by ordinary kriging, three areas were delineated for the whole territory of the province of Córdoba. The Kd <1.5 predominated in Aridisols, Alfisols, and Entisols, and were located predominantly in Southwest and Northwest Córdoba province associated with low clay content and low organic matter content. KdW values> 2.5 L kg-1 were located predominantly in the East-Northeast of the territory. About 85% of the province of Córdoba presented between low and medium sorption capacity (Kdw < 2.5 L kg-1). This study is a first step in mapping the behavior of atrazine. Future studies of susceptibility to contamination with atrazine should incorporate information on topography, climate and soil management, in a geographic information system (GIS).