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

KRAEMER, F. B.; CHAGAS, C. I.; IRURTIA, C.; GARIBALDI, L. A.

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 μm sediment fraction) or associated with small soil particles (2 to 50 μm), therefore management practices, such as filter strips, should be regarded with caution when implemented.