HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Tate, K. W. Articles by Nader, G. Search for Related Content PubMed PubMed Citation Articles by Tate, K. W. Articles by Nader, G. Agricola Articles by Tate, K. W. Articles by Nader, G. Related Collections Animal Waste Surface Water Quality Microorganisms Best Management Practices Water Pollution

TECHNICAL REPORTS

Surface Water Quality

Significant Escherichia coli Attenuation by Vegetative Buffers on Annual Grasslands

^a Department of Plant Sciences, Mail Stop 1, One Shields Avenue, University of California, Davis, CA 95616-8515
^b Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California, 18830 Road 112, Tulare, CA 93274
^c Department of Environmental Science Policy and Management, 151 Hilgard Hall #3110, University of California, Berkeley, CA 94720-3114
^d University of California Cooperative Extension, 142A Garden Highway, Yuba City, CA 95991-5593

^* Corresponding author (kwtate{at}ucdavis.edu)

Received for publication April 28, 2005. A study was conducted to estimate the retention efficiency of vegetative buffers for Escherichia coli deposited on grasslands in cattle fecal deposits and subject to natural rainfall-runoff conditions. The study was conducted on annual grasslands in California's northern Sierra Nevada foothills, a region with a distinct wet–dry season Mediterranean climate. We used 48, 2.0- by 3.0-m runoff plots to examine the efficacy of 0.1-, 1.1-, and 2.1-m buffers at three land slopes (5, 20, and 35%) and four dry vegetation matter levels (225, 560, 900, and 4500 kg/ha) across 27 rainfall-runoff events during two rainfall seasons. Buffer width treatments were implemented by placement of cattle fecal material containing known loads of E. coli 0.1, 1.1, or 2.1 m upslope of the plot runoff collector. Mean total runoff to total rainfall ratio per plot ranged from 0.014:1 to 0.019:1 and reflected the high infiltration capacity of these soils. Approximately 94.8 to 99.995% of total E. coli load applied to each plot appears to be either retained in the fecal pat and/or attenuated within 0.1 m downslope of the fecal pat, irrespective of the presence of a wider vegetated buffer. Relative to a 0.1-m buffer, we found 0.3 to 3.1 log₁₀ reduction in E. coli discharge per additional meter of vegetative buffer across the range of residual dry vegetation matter levels, land slope, and rainfall and runoff conditions experienced during this project. Buffer efficiency was significantly reduced as runoff increased. These results support the assertion that grassland buffers are an effective method for reducing animal agricultural inputs of waterborne E. coli into surface waters.

Abbreviations: RDM, residual dry matter • SFREC, Sierra Foothill Research and Extension Center

This article has been cited by other articles:

				W. A. Miller, D. J. Lewis, M. D. G. Pereira, M. Lennox, P. A. Conrad, K. W. Tate, and E. R. Atwill Farm Factors Associated with Reducing Cryptosporidium Loading in Storm Runoff from Dairies J. Environ. Qual., August 8, 2008; 37(5): 1875 - 1882. [Abstract] [Full Text] [PDF]

				W. A. Miller, D. J. Lewis, M. Lennox, M. G. C. Pereira, K. W. Tate, P. A. Conrad, and E. R. Atwill Climate and On-Farm Risk Factors Associated with Giardia duodenalis Cysts in Storm Runoff from California Coastal Dairies Appl. Envir. Microbiol., November 1, 2007; 73(21): 6972 - 6979. [Abstract] [Full Text] [PDF]