About Us | Help Videos | Contact Us | Subscriptions

Journal of Environmental Quality Abstract - Surface Water Quality

Efficacy of Vegetated Buffer Strips for Retaining Cryptosporidium parvum


This article in JEQ

  1. Vol. 33 No. 6, p. 2243-2251
    Received: Feb 17, 2004

    * Corresponding author(s): ratwill@vmtrc.ucdavis.edu
Request Permissions

  1. Kenneth W. Tatea,
  2. Maria Das Gracas C. Pereirab and
  3. Edward R. Atwill *b
  1. a Department of Agronomy and Range Science, 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


Overland and shallow subsurface hydrologic transport of pathogenic Cryptosporidium parvum oocysts from cattle feces into surface drinking water supplies is a major concern on annual grasslands in California's central and southern Sierra Nevada foothills. Soil boxes (0.5 m wide × 1.1 m long × 0.3 m deep) were used to evaluate the ability of grass vegetated buffer strips to retain 2 × 108 spiked C. parvum oocysts in 200-g fecal deposits during simulated rainfall intensities of 30 to 47.5 mm/h over 2 h. Buffers were comprised of Ahwahnee sandy loam (coarse-loamy, mixed, active, thermic Mollic Haploxeralfs; 78:18:4 sand to silt to clay ratio; dry bulk density = 1.4 g/cm3) set at 5 to 20% land slope, and ≥95% grass cover (grass stubble height = 10 cm; biomass = 900 kg/ha dry weight). Total number of oocysts discharged from each soil box (combined overland and subsurface flow) during the 120-min simulation ranged from 1.5 × 106 to 23.9 × 106 oocysts. Observed overall mean log10 reduction of total C. parvum flux per meter of vegetated buffer was 1.44, 1.19, and 1.18 for buffers at 5, 12, and 20% land slope, respectively. Rainfall application rate (mm/h) was strongly associated with oocyst flux from these vegetated buffers, resulting in a decrease of 2 to 4% in the log10 reduction per meter buffer for every additional mm/h applied to the soil box. These results support the use of strategically placed vegetated buffers as one of several management strategies that can reduce the risk of waterborne C. parvum attributable to extensive cattle grazing on annual grassland watersheds.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2004. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyASA, CSSA, SSSA