Horse manure management is your responsibility if you
Quick Facts on Horse Manure
An average, a 1,000-pound horse produces 9 tons of
manure a year containing valuable fertilizer elements.
Horse owners have a responsibility to manage the
manure that is a by-product of their industry.
Manure is commonly stockpiled prior to use. Adequate
storage area allows for greater flexibility in timing of manure use.
Record keeping is an essential factor in land
application of manure/compost.
The total fertilizer value of the manure produced by
Colorado’s horses is estimated to be $10 million per year.
horse produces 9 tons of horse manure a year (50 pounds per day)
valuable fertilizer elements. (See Table 1.) Add to that an additional
cubic foot of bedding material and you
get 730 cubic feet/year from one
horse. How the manure is stored and treated has a
substantial impact on
its value. The labor, storage and utilization costs for manure
management can be considerable.
industry uses two
principal feed management systems, according to a
recent survey. The first system permits horses to graze full-time on
pastures, and manure management is such that the manure is not
collected or treated. Pasture manure
usually is spread by harrow cultivation that promotes decomposition.
The second system
confines animal feeding, which relies on intensive management, and the
horses are kept in stalls or runs. The horses may be housed in box
stalls and provided a bedding source for urine absorption.
Alternatively, horses are kept in corrals or runs, and some runs are
attached to stalls.
management can happen in one or more of the following
is removed daily and composted);
(manure is removed daily and stored in piles); and /or,
application (manure is removed daily and spread on cropland).
Marketing Plan for Horse Manure Management
Horse owners have a
responsibility for horse manure management that is a by-product of
industry. Develop a management plan for manure and soiled bedding. Use
it on crop lands, arena surfaces, trail surfaces, and landscaping. If
you don’t plan to use the manure yourself, develop a marketing plan so
others can make use of it.
Contract or donate
compost to crop farmers and community landscapers or parks, and
neighborhood gardeners. Offer a discount to boarders if they dispose of
manure. The people who come to watch others ride are another potential
market for manure or compost sales. Before you can market the product,
it must be completely and properly composted and free of foreign
material such as pop cans, wire, and syringes.
Make an arrangement
or contract with a landscaper, nursery or crop farmer. Be prepared to
handle your own by-product. One option may be to deliver manure, at
your cost, to a site where contractors do the composting. Pre-determine
the bedding types they prefer in their compost mix.
Management and Collection
(Stalls, Drylots, and Runs). Daily maintenance of horses in a
confinement setting requires intensive labor. Horses housed in stalls
and sheds require soft absorbent bedding. The most common bedding
sources in Colorado are pine sawdust (80 percent), pine wood chips (17
percent), and straw (2 percent). Some other sources are shredded
newsprint, peanut shells, peat moss, rice hulls, etc. Remove horse
soiled bedding on a regular basis and handle appropriately to prevent
fly infestation and disease transmission.
Horse manure management in pastures depends primarily on getting good
distribution of manure across the pasture. To avoid manure
in isolated spots in a pasture, distribute grazing evenly. Rotational
grazing is one of the best ways to achieve this goal; however, horse
owners don’t usually have large enough pastures for rotational grazing.
On the other hand,
pastures can be split, and the horses moved back and forth between both
parts of the pasture to distribute the manure more uniformly.
Availability of several watering facilities and moving feeding
facilities periodically will encourage better manure distribution.
Avoid grazing during
rainy periods when soils are saturated, to avoid soil compaction and
manure runoff. Restrict access to streams to avoid manure deposition in
or near water bodies. This can be done by fencing or providing shade
away from the streams. Refrain from excessive stocking rates that lead
to overgrazing. Damaging the grass stand increases manure runoff
potential from pastures.
Horse Manure Management and Stockpiling.
Horse manure is commonly stockpiled
prior to use. Adequate storage area
allows for greater flexibility in timing of manure use. Therefore, be
sure you have a large enough storage area to accommodate the manure
produced. Over time, the manure shrinks from decomposition and moisture
selection for the storage area is important to safeguard against
surface and groundwater contamination. Place stockpiles at least 150
feet away from surface water (creeks and ponds) and wells. Establish
and maintain grass buffer strips between water bodies and manure piles.
Construct a perimeter ditch or berm around the storage area, if needed,
to prevent runoff onto or off of the area.
produces a relatively dry end-product that is easily handled and
reduces the volume of the horse manure (40 percent to 65 percent less
and weight than the raw manure). Composting at proper temperatures can
kill fly eggs and larvae, pathogens and weed seeds. Compost has less of
an odor compared to raw manure and is more easily marketed. Composted
manure acts as a slow release fertilizer and an excellent soil
To be done right,
composting requires an investment of time and money. Machinery required
includes a tractor, a manure spreader and a front-end loader. Some
ammonia-nitrogen is lost during the composting process, and an ammonia
odor may result for a short period. When composting is done on a large
scale, additional land and machinery requirements exist.
Microbes that drive
the composting process require optimum conditions of temperature,
moisture, oxygen, and carbon:nitrogen (C:N) ratio. The C:N ratio should
be between 25:1 and 30:1; horse manure has an estimated C:N ratio of
50:1. With the addition of bedding material (high carbon content), the
C:N ratio will be even higher. Therefore, N has to be added to the
manure for it to compost properly.
The addition of grass clippings,
hay, or fertilizer [25 to 30 pounds N/ton of manure (75 to 90 pounds of
ammonium nitrate or 50 to 65 pounds of urea)] should bring the C:N
ratio into the optimum range. When microbes work properly, the compost
temperature will be between 120 and 160 F. Cooler temperatures result
from a lack of N. When the composting process is complete, the
temperature will cool naturally.
It is important to
have the right balance of moisture and air for the microbes to process
the horse manure. The compost should be moist but not soggy, and may
be watered or covered with plastic to maintain moisture. Aerate the
compost by turning it regularly. The manure and bedding particles
should be about one-half inch to one and a half inches in size.
Composting does require effort, but the result is a more easily used
and economically valuable fertilizer.
Horse Manure Management and Application of Manure
Manure Management for Land Application
Record keeping is an essential factor in
land application of manure/compost. It is critical to know how much
manure/compost was applied to each field and when it was applied.
Analyze manure/compost regularly and record the lab results for future
reference. Note changes in nutrient value and factor them in when
calculating future application rates.
Manual loading and
land application are labor intensive and impractical for managing the
manure generated by more than 25 horses. Consider mechanical loading
and application with a bobcat or tractor-operated loader when the
manure or the land application becomes large.
horse manure/compost uniformly to achieve an acceptable application
finer textured and more uniform the manure, the easier it is to apply
uniformly. Spreaders apply manure/compost at different rates depending
on ground speed, PTO speed, gear box settings, discharge openings, and
manure moisture and consistency.
Do not apply horse
to land that is highly erodible, frozen or saturated. To protect water
sources from manure runoff, do not spread manure within at least 150
feet of a water source (such as a well, creek or pond). Incorporate
manure into the soil as soon as possible. Mixing the manure with the
soil immediately reduces losses of manure nutrients to runoff and
volatilization, and reduces odor problems associated with manure left
on the soil surface.
manure/compost application rate on crop N needs and available soil and
manure N levels. Test your soil and manure for N levels at a certified
laboratory. In general, the higher a crop yield goal, the greater the N
requirements. Irrigated crops also tend to need more N. If yield goals
are lower than those shown in Table 2, decrease the manure application
rate and increase the land application area. If yields are higher, less
land is needed. Soils high in organic matter and nitrate have higher
available N in the soil and require less N.
Table 1: Average fertilizer content
in horse manure (as-is basis).
Average manure application rates and land base (area) requirements for
*The land base needed is the
cropland requirement for manure application alone, not for grazing and
forage needs. One ton = 2,000 lbs. One acre = 43,560 sq ft.
Manure Mangement for Landfills
Manure and compost are
sometimes landfilled, dumped in gullies and used
to repair roads. These are not recommended practices due to high runoff
and leaching potential from gullies and roadways. If the areas are not
vegetated and are waterways for storm runoff, the potential for runoff
of manure nutrients into creeks and ponds is high. When excessive
nutrients exist in surface waters, plant and algal growth becomes
extreme, the oxygen supply is depleted, and fish can be killed.
Manure Management for Riding Arenas
ideal arena surface provides
resilient footing for optimum horse performance. Drain the arena well,
maintain adequate depth to protect horses’ legs from contusions, and
keep the arena absorbent to hold moisture efficiently and prevent dust.
The arena surface also must be odor-free. Composted manure/bedding
makes an ideal surface addition when mixed with river sand and wood
products. Uncomposted manure and bedding results in ammonia fumes that
can cause respiratory problems in horses. Surface depth of compost
depends on soil type and climate; too much organic matter can hold
excess moisture and may cause the horses to slip and fall.
Table 3: Maximum
manure application rates to avoid soil salinity problems.
T = Ton; A = acre
EC = electrical conductivity measured in units of
millimhos/centimeter. Note: The manure application rate should be based
on N needs of the crop within this maximum range. This table assumes
that manure is not incorporated, which is typical for perennial forage
Horse Manure Management and Precautions
Virtually no viral
diseases are transmitted between horses and humans through fecal
material, but some bacteria and protozoans (such as E. coli and
Giardia) can be transmitted in this manner. Therefore, handle horse
carefully to prevent disease transmission. In addition, horse manure
runoff into waterways may produce fecal coliform contamination levels
that can be potentially hazardous to fish and anyone who drinks that
Manure Management and Runoff
water from dry lots, pastures, and manure storage or compost
areas carries pollutants (such as nitrogen, phosphorus, and bacteria)
into surface waters. Avoid over-irrigation of pastures. Build berms or
trenches to prevent water from entering or leaving dry lots and manure
storage and composting areas. Do not allow a creek or irrigation canal
to pass through drylots.
Prevention and Control
Horses pick up parasites by
ingesting grass, feed, or water that is contaminated with parasite
larvae and eggs. The most common internal parasites of horses are the
ascarids, strongyles (large and small), pinworms and bots.
Manure and Insect
Excellent fly-breeding conditions occur in
mixtures of manure, spilled feed and decaying bedding. To help
eliminate these areas, remove and spread the manure regularly and
prevent accumulation of other wastes. Composting at proper temperatures
inhibits fly development. Several pesticides can be used on manure
piles to kill maggots. However, we would suggest planting the following
in and around the paddocks to deter flies:
Cover manure stockpiles or
compost sites to
exclude flies and prevent their development.
piles can provide an ideal environment for the bumble flower beetle
white grub. White grubs feed on decaying manure; however, these grubs
do not damage home lawns. Therefore, there is no need to control them.
standing water to reproduce; therefore, it is imperative to prevent
ponding of water in manure storage areas.
Manure and Salinity
tends to be high in salts, which when land applied at excessive
rates, contribute to soil salinity. Soil salinity causes plants to
become water stressed or, in extreme cases, die. When manure is not
soil-incorporated, as in applications to pasture, the salts accumulate
on the soil surface unless they are leached into the subsoil.
Irrigation or rainfall may move salts out of the topsoil and move them
into deeper depths of the soil profile. If salinity levels in the soil
and manure are known, use Table 3 to determine acceptable maximum rates
of manure application for most forages to avoid excessive soil salinity
Manure Management and Weeds
weed is an unwanted, out-of-place plant. Weeds compete with crops for
limited resources of water, nutrients and light. Manure has contributed
to weed problems where it has been applied to cropland. Use composted
horse manure to avoid these problems. When manure is composted, the
temperatures achieved during the composting process kill most weed
seeds. Some weed infestations may be the result of overgrazing, not due
to manure applications.
Parasite Preventions and Controls in Horse Manure
De-worm all horses on a regular schedule.
Manure Management for Parasite Control:
manure from stalls, small corrals, and paddocks on a daily basis.
Compost all manure to a temperature of 145 F for at least two weeks to
kill most parasite eggs, or compost at lower temperatures for longer
periods of time.
Spread manure on pastures only after composting.
Manure that has not been composted should be spread only on crop land
or other ungrazed, vegetated areas.
Manure and Pasture Management:
Mow two to four times a year and chain
harrow (drag) to break up manure pile and expose parasite eggs
to the elements.
Practice rotational grazing if possible.
Graze young horses separately from
older horses; the younger horses
have a higher susceptibility to parasites.
Follow horses with cattle or sheep
before returning a pasture to
horses. This interrupts the life cycles of horse parasites.
Deep harrow or plow pastures that are
badly parasite-infested. Deep
plow pastures and reseed every three to five years. This also helps
break parasite cycles.
Use feeders, racks, bunks or mangers for feeding hay and grain. This
will prevent feed from getting mixed with feces. Don’t feed off the
Provide horses a clean, fresh drinking water supply.
Avoid water contaminated with feces.
by J.G. Davis and A.M. Swinker
Spencer, W., and D. Tepfer. 1993. 3.762, Economics of
composting feedlot manure. Colorado State University Cooperative
Wilson, C.R., and J.R. Feucht. 1991. 7.212, Composting
yard waste. Colorado State University Cooperative Extension.
Waskom and Davis. 1999. BMPs for Manure Management,
Colorado State University bulletin no. 568a.
Davis, Colorado State University Cooperative Extension environmental
soil specialist and professor, soil and crop sciences; and A.M.Swinker,
former Cooperative Extension horse specialist and associate professor,
animal sciences. Reviewed 1/2002.
Source: Colorado State University Equine Extension
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