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(Conservation Currents,
Northern Virginia Soil and Water Conservation District, September
2005)
 A
sacrifice area, also known as a "pen," is an essential
component of horse rotational grazing systems on small acreages.
It is a relatively flat outdoor area on which no grass is expected
to grow and which provides an alternative to pasturing. The
area can be used for the horses' much needed daily exercise,
and provides an alternative outlet for the animals during saturated
soil or drought conditions. The sacrifice area can also be used
when pastures are over-grazed or require maintenance. Including
a sacrifice area in your horse operation will reduce soil loss
and water pollution by preventing erosion and can save you time
and money by decreasing pasture maintenance requirements.
Poorly sited, constructed and/or managed sacrifice
areas are vulnerable to erosion, and can become potential sources
of non-point source pollution (e.g. from manure and urine) for
surface and ground water. The following guidelines outline considerations
associated with installation and maintenance of a sacrifice
area.
In situations where horses are left unattended
for many hours per day, the sacrifice area should be easily
accessible to and from their stalls and equipped with watering
and feeding amenities. Should the sacrifice area be located
away from a barn or stall, then the horses should have access
to shelter. A run-in shed, a three sided-structure with a roof
that is large enough for the horses to enter and leave freely,
is typically sufficient. An operation with multiple horses can
have more than one sacrifice area—a large one next to the
barn and additional smaller areas located within or next to
larger fields. A gated access to a pasture from each sacrifice
area makes for a "chore-efficient" operating system.
Areas that are on higher ground with a slight
slope of 1-2 percent (for drainage) are ideal locations for
sacrifice areas. Low spots, natural drainage areas, floodplains,
and resource protection areas (RPAs) are poor locations for
sacrifice areas. Consider relocating a sacrifice area if it
is currently within these problem areas. Avoid areas with slopes
(30 percent or greater) that are susceptible to erosion.
A sacrifice area can be of any shape. For one
horse, an area can be as small as 14 feet by 24 feet. The basic
rule of thumb is that a full-grown horse should be able to make
convenient turns within the sacrifice area. If the area is to
be sized for multiple horses, it should be large enough for
a horse to easily get away if it is about to be cornered by
a dominating stable mate. The size of a sacrifice area should
be limited to just what is actually needed. The smaller the
area, the less challenging it will be to manage its pollution.
1. Grade an area to serve as the sub-base
(the sub-base is the earth or native soil).
2. Cover the sub-base with a sheet of geotextile fabric.
Tuck the loose ends of the fabric into trenches along the perimeter.
The fabric keeps the base material from sinking into the sub-base
over time.
3. Spread a base layer about six inches thick,
consisting of a mix of three-fourths to 3-inch sized crushed
igneous rock or limestone. The base is the layer of material
between the native soil and the upper most layer on which the
horses exercise. This gravel layer protects the area from erosion
and enhances drainage within the site.
4. Spread a layer of footing three to four
inches thick (the final layer) to provide a comfortable "hoof-cushion."
This should consist of any material that does not compact well
such as sand, crusher run, rubber chunks, mulch or ground limestone.
Ground limestone provides an advantage over other footing materials
because it chemically neutralizes horse urine odor. Be careful
not to use too fine a footing material as the footing will compact,
reducing infiltration and causing ponding within the sacrifice
area.
5. Prevent wash-off of the footing material by installing kickboards
made of railroad ties.
6. To keep excess rain or melted snow from flowing through the
sacrifice area, divert runoff around the sacrifice area by installing
ditches, or connecting roof gutters to downspouts
and piping the runoff around the area. Installation of a vegetated
buffer to filter pollutants in runoff from the sacrifice
area is also highly recommended.
7. Locate the run-in shed structure at the corner of sacrifice
area, so that roof runoff from this structure can be easily
diverted from the sacrifice area. The shed should be oriented
such that it provides protection for animals from winter's northerly
and north-westerly winds.
8. Use regular fencing to determine the size
and shape of the sacrifice area.
ILLUSTRATION NOT TO SCALE
1. Maintain a grass filter strip along the downslope sides of
the heavy-use area. This will trap sediment and other pollutants
in runoff.
2. Remove manure, soiled bedding and uneaten feed daily, especially
before a rain or snow event. Manure accumulation leads to mud
problems because it retains water. Scrape off all manure before
winter.
3. Practice dust control measures. Sprinkle water on sacrifice
areas to keep dust down during the dry summer months. This also
will help prevent the accumulation of urine salts.
4. New footing material may need to be added every two to three
years.
Caution: To avoid ingestion of footing material
by horses, always provide hay or feed in an elevated hay/feed
dispenser. |
