The purpose of this study was to evaluate the effects
that free ranging cattle have on water quality in semi-arid
environments. There were three specific objectives:
1) To determine the concentration and distribution of
cattle feces in meadows, riparian zones, and the
associated uplands. 2) To determine the fecal deposition
rate of free ranging cattle directly into a stream. 3) To
determine if feces near a stream, up to 2.3 meters away,
are a source of pollution during rainfall and subsequent
surface runoff.
As the distance from water and slope increased cow-chip
concentrations decreased. The highest concentration
of cow-chips was found in the meadows where winter
supplemental feeding occurred. The second highest
concentration of cow-chips was found in the riparian
zones. Areas that had steep slopes and were a long
distance from water had the lowest concentration of cowchips.
The amount of time the cattle spent in the stream and
the fecal deposition rate changed by season. The cattle
spent the most time in the stream during the summer, and
the least amount of time during the fall. The direct
fecal deposits were highest for summer and approximately
the same for the other seasons.
In the experiment designed to evaluate the
effectiveness of buffer strips, feces were placed varying
distances from the edge of simulated rainfall plots and
subjected to different levels of precipitation. A
significant reduction in conform concentrations was noted
between the bacteria which traveled 0.7 meters through a
buffer strip, as compared to those which did not have any
distance to travel. Bacteria concentrations at the 0.0
meter distance averaged 42,800 coliforms/ml, whereas there
were only about 2,250 bacteria/ml delivered from the feces
deposited 0.7 meters away. No statistical differences
were found between buffer strip widths of 0.7 meters and
2.3 meters. Buffer strip effectiveness for widths greater
than 2.3 meters were not investigated and thus remain a
subject for further investigation
