Abstract

ARES, María Guadalupe; VARNI, Marcelo  and  CHAGAS, Celio. Erosión Hídrica En Una Microcuenca Agrícola Bajo Siembra Directa Del Centro De La Provincia De Buenos Aires. Cienc. suelo [online]. 2014, vol.32, n.2, pp.259-270. ISSN 1850-2067.

In the hilly area of Tandilia, in the Argentine Humid Pampas region, the unsustainable adoption of no- tillage practices has resulted in the reduction in vegetation cover and its protective effects. In addition, the rainfall increase recorded in recent decades has contributed to increase runoff and soil susceptibility to water erosion in the area. The aim of this study was to analyze the dynamics of sediment concentrations generated by water erosion and to study relationships with rainfall, runoff, and previous precipitation events in a watershed under no-tillage. Results indicate that runoff showed a high temporal variability. The suspended sediment concentration showed the highest correlations with runoff variables, while runoff was significantly correlated with the erosivity index. Contrary to expectations, precipitation of the previous 5 days was not correlated with runoff or sediment production. The analysis of the rainfall-runoff-sediment production interaction allowed identifying different erosive responses that could be associated alternatively with sheet erosion or with rill erosion as major processes in the watershed, according to the magnitude of the considered event. The most frequent type of erosion may be inter-rill erosion. Meanwhile, rill erosion may be less frequent. According to these results, the natural high infiltration capacity of these soils should be preserved, and, at the same time, erosive runoff should be controlled.

Keywords : Suspended sediment concentration - Discharge - Sheet erosion - Rill erosion.

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