Small commercial and non-commercial animal enterprises (SCAEs) raise a few
beef cows, horses, pigs, sheep, poultry, and other animals on a few acres. These
enterprises are often located in suburban areas of watersheds and show potential for
degrading water quality through to increased bacterial, nitrogen, and phosphorus
concentrations. SCAEs implement Best Management Practices (BNIPs) on a voluntary
basis to control their water quality impacts.
Off-stream watering areas, with animal access to streams, and covered manure
storages are two BMPs which were analyzed in this thesis for effectiveness in reducing
bacteria, nitrogen, and phosphorus from entering surface and groundwater in four SCAEs.
The four cooperating SCAEs were located in the Tualatin River Basin, and the potential
water quality improvements from implementing these two practices in all SCAEs in the
basin were discussed.
The BMP analyses use results from several studies. Two of these studies analyzed
off-stream watering areas for reducing time animals spend watering at the stream. This
time was measured and used to estimate the manure defecated in the stream. Reducing
time animals spend at the stream decreases direct defecations in the stream and reduces
water quality impacts of SCAEs. A third study analyzed a pasture pump as a possible off-stream
watering device. It was analyzed for its ability to provide water to 27 Holstein
dairy heifers without limiting water consumption. Daily water consumption from the
pasture pump was not significantly different than daily consumption from an open water
trough. A fourth study predicted the rainfall required to produce runoff from pastured
areas in the Dairy-McKay Hydrological Unit Area within the Tualatin River Basin. These
required rainfall amounts and runoff frequency were predicted for summer and winter soil
conditions.
The BMPs were analyzed for a variety of wet and dry conditions during the
summer and winter. Off-stream watering areas were most effective in reducing water
quality impacts of SCAEs for dry conditions during the summer and winter, while the
covered manure storages were most effective during winter days of continuous rain. Off-stream
watering areas reduced the time animals spent at the stream by 75%.
Consequently, defecations at the stream were assumed to be reduced 75% and the
SCAEs'water quality impacts decreased. Covered manure storages protect manure piles
from rain and surface water runoff and prevent bacteria and nutrients from entering the
stream or leaching to groundwater regardless of the weather. However, the amount
prevented varies with weather conditions. An uncovered manure pile was estimated to
cause no water quality impacts during dry weather. During wet weather, the bacteria and
nutrients reaching the stream from an uncovered manure pile was estimated to be 60% of
the quantity released. The maximum amount of nitrogen leaching to groundwater was
estimated to be 10% of the amount applied to the pile since the previous rain.
In addition to implementation costs of BMPs, there are changes in annual revenue
and costs associated with the management changes. Partial budget analyses were
conducted for the four SCAEs to determine their changes in annual monetary returns to
management. Both BMPs resulted in negative changes in annual returns to management
for all four enterprises. / Graduation date: 1994
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35644 |
| Date | 24 February 1994 |
| Creators | Godwin, Derek C. |
| Contributors | Miner, J. Ronald |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
Page generated in 0.0013 seconds