(Georgia Institute of Technology, 2005-04)
Byers, Harris L.; Cabrera, Miguel L.; Matthews, Monte K.; Franklin, Dorcas H.; Andrae, John G.; Radcliffe, David E.; McCann, Mark A.; Kuykendall, Holli A.; Hoveland, Carl S.; Calvert, Vaughn H., II
Contamination of unfenced streams with
phosphorus, sediments, and pathogenic bacteria from
cattle activity may be affected by the availability of
shade and alternative water sources. The objectives of
this study were to evaluate water quality in two streams
draining tall fescue/ bermudagrass pastures with
different shade distributions, and to quantify the effects
of alternative water sources on stream water quality.
Loads of DRP, TP, and TSS were measured during
storm flow, and loads of DRP, TP, TSS, and E.coli
were measured every 14 d during base flow in two
streams located in the Piedmont region of Georgia.
Our results showed that grazing cattle in pastures with
unfenced streams contributed significant loads of DRP,
TP, TSS, and E. coli to surface waters (p<0.01).
Although storm flow was similar in both streams, loads
of DRP, TP, and TSS were larger (p< 0.08) in the
pasture with the smaller amount of non-riparian shade.
Water trough availability significantly decreased (p<
0.08) base flow loads of TSS and E. coli in both
streams. Our results indicate that possible BMPs to
reduce P, sediment, and E. coli contamination from
beef-cattle-grazed pastures may be to develop or
encourage non-riparian shade and to provide cattle with
an alternative water supply away from the stream.
(Georgia Institute of Technology, 2003-04)
Matthews, Monte K.; Cabrera, Miguel L.; Franklin, Dorcas H.; Radcliffe, David E.; Andrae, John G.; Calvert, Vaughn H., II
Information about cattle impact on streams is limited in the southeastern United States. This study is being conducted to determine the effects of stream fencing and use of water troughs on stream water quality in the Georgia Piedmont. Base flow and storm flow samples are taken and analyzed for N, P, E. coli, total sediments, turbidity, dissolved oxygen, and temperature. Global Positioning System collars are used to track cattle and determine the amount of time spent within the stream riparian area. Results from the first year of the study showed that the amount of time cattle spent in riparian areas (over 10%) was positively correlated with daily maximum air temperature (r2 =0.92). Additional results reveal that the concentration of E. coli in base flow samples was higher in unfenced than in fenced streams, and also showed a positive relationship with the time cattle spent in riparian areas. Maximum dissolved reactive P concentrations in storm flow were higher in unfenced than in fenced streams. Removing water troughs from the pasture resulted in an immediate increase in the amount of time cattle spent near the streams.