Influencia de las propiedades edáficas y la posición en el paisaje sobre la respuesta hidrológica de suelos pertenecientes a una cuenca de la Pampa Ondulada

Abstract

Research in the Tala´s Creek Basin (Rolling Pampa, Argentina) including the monitoring of gauged watersheds and field rainfall simulation experiments is being carried out. It showed disagreement between the hydrological response of a small arable watershed compared to a basin of 400 km2 containing both arable soils and non arable sodic soils. The objective of this work was to assess the generation of surface runoff and soil erosion corresponding to four treatments whose soils and land use are representative of the studied region. The field trials consisted in the application of highintensity simulated rainfall on soils under bare surface condition. Unlike the rest of the treatments, the situation under livestock use with low organic carbon content, poor physical condition and high percentage of exchangeable sodium at the topsoil, showed the lowest final infiltration rate (1 mm h-1) and the largest sediment yield (349 g m-2). Due to its position close to the main stream, this site can pose an important risk to the studied water course because it is a source of physical, chemical and biological contaminants. These results show that sodic soils may be partially responsible for the lack of agreement between the small watershed and the basin’s hydrological response to rainfall events.