Summary and Implications
Different grazing management practices in pastures may affect the sward and physical characteristics of riparian areas which affect sediment, phosphorus, and fecal pathogen loading of the pasture streams. To measure these effects, six 30-acre cool-season grass pastures, bisected by a stream, were split into two blocks with three treatments per block. Pastures were grazed by continuous stocking with unrestricted stream access (CSU), continuous stocking with access to the stream restricted to a 16-foot wide stabilized stream crossing (CSR), or rotational stocking (RS). For data and sample collections, pastures were divided into 4 zones: on the streambank (streambanks zone), 0 to 110 feet from the streambanks (110 zone), 110 and 220 feet from the streambank (220 zone), and greater than 220 feet from the streambank (upland zone). Forage heights were measured and forage samples were collected and analyzed for dry matter and mass from areas where cattle did or did not congregate in each zone monthly from May to October. The percentages of bare and fecal-covered ground were also measured monthly at each sampling site. Sward heights were lower in cattle congregation areas than open areas through all months (P < 0.05). In the later months of the grazing season, sward heights and forage mass were less in the streambanks and 110 zones of the CSU pastures than CSR pastures. Pastures with CSU also had higher (P < 0.10) percentages of fecal-covered ground cover in the 110 zone than the other treatments through August. There were few significant differences between treatments for forage sward height, forage mass or bare or fecal-covered ground in the 220 and upland zones in any month.
Iowa State University
Schwarte, Kirk A. and Russell, James R.
"Grazing Management Effects on the Sward and Physical
Characteristics Relative to Streams in Cool-Season Grass
Animal Industry Report:
AS 655, ASL R2439.
Available at: http://lib.dr.iastate.edu/ans_air/vol655/iss1/62