Bacterial retention in three soils of the Rolling Pampa, Argentina, under simulated rainfall

FILIPE BEHRENDS KRAEMER; CELIO IGNACIO CHAGAS; CARLOS IRURIA; LUCAS ALEJANDRO GARIBALDI

Journal of Soil Science and Environmental Management

Academic Journals

Año: 2011 vol. 2 p. 341 - 353

2141-2391

Bacterial retention by soils is a key factor in predicting bacterial transport through surface runoff into water bodies. The objective was to evaluate biological, soil and hydrologic factors that affect bacterial retention in three soil types of the Rolling Pampa, Argentina. Simulated rainfall was applied on field plots previously inoculated with  Escherichia coli  and simultaneously  biological variables  such as bacterial  adsorption and distribution coefficient  were measured  at laboratory.  Soil variables, particularly pH, exchangeable  sodium percentage and organic carbon as well as biological variables proved to be important properties in the regulation of bacterial retention processes. There were no significant differences between the biological variables measured in soils and in the sediments. Most of the microorganisms in the runoff from all sites were either free of (in the < 2 ìm sediment fraction) or associated with small soil particles (2 to 50 ìm), therefore management practices, such as filter strips, should be regarded with caution when implemented.