title: Impact of riparian zone protection from cattle on nutrient, bacteria, F-coliphage, and loading of an intermittent stream.
abstract: This 5-yr study compared, via an upstream-downstream experimental design, nutrient and microbial water quality of an intermittent stream running through a small pasture (∼2.5 animals ha) where cattle are restricted from the riparian zone (restricted cattle access [RCA]) and where cattle have unrestricted access to the stream (unrestricted cattle access [URCA]). Fencing in the RCA excluded pasturing cattle to within ∼3 to 5 m of the stream. Approximately 88% (26/32) of all comparisons of mean contaminant load reduction for lower, higher, and all stream flow conditions during the 5-yr study indicated net contaminant load reductions in the RCA; for the URCA, this percentage was 38% (12/32). For all flow conditions, mean percent load reductions in the RCA for nutrients and bacteria plus F-coliphage were 24 and 23%, respectively. These respective percentages for the URCA were -9 and -57% (positive values are reductions; negative values are increases). However, potentially as a result of protected wildlife habitat in the RCA, the mean percent load reduction for  for "all flow" was -321% for the RCA and 60% for the URCA; for , these respective percentages were -209% (RCA) and 73% (URCA). For "all flow" situations, mean load reductions for the RCA were significantly greater ( < 0.1) than those from the URCA for NH-N, dissolved reactive phosphorus (DRP), total coliform, , and . For "high flow" situations, mean load reductions were significantly greater for the RCA for DRP, total coliform, and . For "low flow" conditions, significantly greater mean load reductions were in favor of the RCA for DRP, total P, total coliforms, fecal coliforms, , and . In no case were mean pollutant loads in the URCA significantly higher than RCA pollutant loads. Restricting pasturing livestock to within 3 to 5 m of intermittent streams can improve water quality; however, water quality impairment can occur if livestock have unrestricted access to a stream.
authors: Agriculture and Agri-Food Canada, Ottawa, ON, Canada.
authors: M D
authors: MD
authors: Sunohara
authors: E
authors: E
authors: Topp
authors: G
authors: G
authors: Wilkes
authors: N
authors: N
authors: Gottschall
authors: N
authors: N
authors: Neumann
authors: N
authors: N
authors: Ruecker
authors: T H
authors: TH
authors: Jones
authors: T A
authors: TA
authors: Edge
authors: R
authors: R
authors: Marti
authors: D R
authors: DR
authors: Lapen
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D002417:Cattle; D003090:Coliphages / Q000302:isolation & purification; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000382:microbiology; D009584:Nitrogen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D045483:Rivers / Q000737:chemistry* / Q000382:microbiology*; D012988:Soil Microbiology; D014867:Water / Q000737:chemistry*; D014871:Water Microbiology; D014873:Water Pollutants; D014876:Water Pollution / Q000517:prevention & control
chemical_list: D014873:Water Pollutants; D014867:Water; D010758:Phosphorus; D009584:Nitrogen