A L A B A M A A &
M A N D
A U B U R N U N I V E R S I T I E S
THE VALUE AND USE
OF POULTRY MANURES
Charles C. Mitchell, Extension Agronomist, Agronomy and Soils
James 0. Donald, Extension Agticultural Engineer, Agricultural Engineering
Poultry manure, properly
is the most valuable of all manures produced by livestock. It has
historically been used as a source of plant nutrients and as a soil
amendment. However, in areas of intense poultry production,
overfertilization of pasture land with poultry manure occurs. The
result is suspected ground water and surface water problems as excess
nutrients run off the land or leach into ground water supplies.
To obtain maximum economic value of plant
nutrients in poultry manure and to protect our water supplies from
excessive nutrient runoff or leaching, poultry manure should be applied
to match nutrient needs of crops.
NUTRIENT ANALYSIS OF BROILER LITTER
Two basic types of poultry wastes are
produced in Alabama: broiler litter and caged layer manure. Broiler litter,
for the purposes of fertilization, includes all floor-type birds such
pullets, and floor layers. Bedding material such as wood shavings or
peanut hulls is used to absorb liquids. Caged layer manure is usually
free from litter material and generally has a higher moisture content.
Both types of waste will contain feathers and some wasted feed.
Chemical analysis of either type of
manure varies due to moisture, temperature (more N will be lost at
amount and kind of bedding, amount of soil picked up while a house is
cleaned, number of batches consecutively reared, and conditions under
which the manure was stored and handled prior to spreading. Alabama
broiler litter is less variable than caged layer manure.
Between 0.5 and 0.7 pound of
litter is produced per pound of market weight. Because
broiler production has become more efficient in recent years, there
is less waste produced per pound of market weight than 10 years ago
when the value was around I pound of litter per pound of market
weight. The decrease in waste per pound is due to drier litter
(less than 20 percent moisture compared to more than 30 percent
10 years ago), improved feed conversion, and more birds on
Layer manure is highly
variable because each operation collects, stores, and handles
manure differently. Nutrient content in broiler litter and layer
manure from different sources and surveys is reported in Tables 1 and 2.
Caged layer manure generally
contains between 1 and 2 percent N on a fresh weight basis (4 to 7
percent on a dry weight basis) if collected at 1- to 3-week intervals.
However, under high-rise houses where layer manure sometimes
accumulates for long periods of time, some N is lost into the air as
ammonia gas. At the same time, manure dries which increases
concentration of all nutrients.
Moisture is the most important
variable to consider when manure is spread by the ton. Manure will
average 70 to 77 percent moisture when excreted. However, broiler
litter dries under normal house conditions and will average about 20
percent moisture. Caged layer manure is much more variable
depending upon the storage system. Because manures and litter are
spread by the ton as they are removed from the house or from
storage, analyses should be compared on a fresh weight basis.
Table 1. Average Nutrient
Composition Of Alabama Broiler
Litter On A Fresh Weight Basis.
| Number of samples
Primary Plant Nutrients
| Total N, %
Secondary Plant Nutrients
| Ca, %
| Cu, ppm
| As, ppm
Weighted mean is calculated from four separate surveys conducted in
Alabama from the mid-1980s through 1993. The surveys included a total
of 207 samples.
Table 2. Nutrient Composition Of fresh, Caged Layer Manure.
North Carolina c
| Moisture, %
Primary Plant Nutrients
| Total N, %
Secondary Plant Nutrients
| CA, %
|| CU, ppm
Patterson, P.H., 1994. Estimating manure production based on nutrition and
Laying hens. Proc. 1994, Poultry Waste Management
Symp. pp. 90-96.
b Shipp, R. F., H. C. Jordan, W. W. Hinish,
and D. B. Beegle. 1981. Spec. Cir. 274.
The Pennsylvania State
Univ. College of Agriculture, Extension Service.
University Park, PA.
c Zublena, J. P., J. C. Barker, and T. A. Carter
. 1993. Poultry manure as a fertilizer source.
North Carolina Coop.
Ext. Serv. Soil Facts. Raleigh, NC.
Poultry manure is managed
primarily for its nitrogen (N) value. However, N availability from
broiler litter is the most difficult of the three primary nutrients to
predict. About one-third of the total N in broiler litter is in the
ammonium form (NH4-N) and the rest is in an
organic form. The amount of N available for plant uptake is
ammonium nitrogen plus the amount of organic nitrogen that
mineralizes during the growing season.
From Table 1
, broiler litter
has the following average nutrient content:
||3- 3- 2 |
|Total nutrients (lb./ton):
Available nutrients first season (lb./ton):
The ammonium N fraction (NH4-N) is subject to conversion to ammonia
gas (NH3 ) and atmospheric loss (volatilization). When
manure has a strong ammonia odor or is spread on the surface of a soil
and not incorporated, significant N will be lost to the air. Losses typically
range from 15 to 50 percent of the ammonium fraction (5 to 20 percent
of total N) when broiler litter is surface applied. If layer manure is
spread as a liquid or slurry, as much as 75 percent of the
ammonium N (one-fourth of total N) could be lost within 7 days after
spreading when the weather is hot and dry and manure is not
soil-incorporated. Of course, incorporation is not practical or even
desirable in some situations such as pastures or hay fields, and
ammonium N loss should be deducted from the total amount to be
Organic N. The
organic N fraction gradually becomes available for crop uptake as the
manure decomposes (mineralizes). Mineralization rates can range
from 40 to 90 percent depending on environmental conditions. For
broiler litter in Alabama, assume that 60 percent of the organic N may
be released during the first year following application. Therefore,
around 70 percent of the total N in broiler litter will be available to
the crop the first year after application.
Phosphorus (P) And
Potassium (K). The P and K fractions are considered to be
about 75 percent as effective as commercial fertilizers during the
first year of application. If litter is applied at rates that will supply
all N needed by the crop, P and K applications greater than those
needed by the crop may occur. Under frequent manure applications,
P will build up in soils to extremely high levels. Potassium may
also build up unless large quantities of hay or forage are removed.
FERTILIZER VALUE OF BROILER LITTER
Estimated value per pound of
nutrient is based upon the 1995 retail cost for ammonium nitrate
(34-0-0), liquid N solution (32-0-0), concentrated superphosphate
(0-46-0), and muriate of potash (0-0-60):
Using an average fertilizer
grade of 3-3-2 (Table 1), a reasonable estimate of the value of
broiler litter would be about $37 per ton. if only readily available
nutrients are considered, then the value would be
around $25 per ton.
When applying poultry
manure to cropland, pastureland, and hayfields, consider the following:
- Determine the nutrients in the manure prior to spreading.
An analysis by a commercial laboratory determines moisture,
total N, and other plant nutrients and allows the farmer to
calculate the value of the manure and how much to apply. if a
chemical analysis is not made, average nutrient contents of
broiler litter can be used such as 60-60-40 pounds total
O per ton or 40-40-30 pounds of available nutrients per ton.
If litter is analyzed for available nutrients, keep in mind that
stored litter can change over time unless protected.
- Credit previous manure applications. If more than 4 tons per
acre of broiler litter has been applied during the past 2 years,
residual soil organic N should be considered. About 5 pounds
of N per ton of litter applied last year will become available to
this year's crop. This amount needs to be subtracted from the
total N recommended for the crop.
- Soil test for residual nutrients. Soil testing provides the best
estimate of residual P and K in the soil and other soil
amendments (such as lime) that should be applied for optimum
yields and efficient nutrient use. If soil test P is rated very
high (VH) or extremely high (EH), consider using a commercial
fertilizer that does not contain P, such as 15-0-15 or
ammonium nitrate (34-0-0). Continued application of
manures, especially broiler litter, will increase soil P to the point
that surface water enrichment with P could result. If soil
test P is not VH or EH, apply litter or manure based upon
recommended N rate for the crop to be grown. The
N recommendation is given on the soil test report. Exceeding
recommended rates for available nutrients by more than 50
percent could result in excessive N leaching in some soils or
potential surface runoff into streams.
- Calculate litter or manure needs based upon N availability.
For example, 60 pounds of N per acre is recommended for
fescue pasture in the fall and again in the spring. If 1 ton of
litter contains 40 pounds of available N, then 1.5 tons should
be applied per acre in the fall and again in the spring.
- Check application rates. Check the actual rate that is applied
by calibrating spreading equipment. A drop cloth to collect
and weigh the litter that is spread on the field is a quick way to
estimate application rate (See Circular ANR-889 "Calibrating
Poultry Litter Spreaders").
- Apply litter at the right time. Timing of application should
correspond to the time of year when the crop can use the nutrients.
Applying litter when there is no actively growing crop or at a time
of the year when the crop is dormant is inefficient use of plant
nutrients and could result in surface and ground water contamination.
ADDITIONAL FACTS ABOUT
USING POULTRY MANURE
Storage. Broiler litter is most valuable
immediately after it is removed from the house. The N in the
litter can be preserved if it is stored in an enclosed structure
(dry stack barn) or in a deep pile that is covered
(See Circular ANR-839, "Broiler Litter Storage"). Never
store litter outside and exposed to the weather! Broiler
litter should be handled like commercial fertilizers. Rain
can leach valuable nutrients into surface waters. Manure
stored outside and exposed to the weather will decompose
rapidly. An ashy-gray appearance indicates a loss of
Broiler Litter. When broiler litter is exposed
to air and moisture, the ammonium N component is converted
to organic N. Therefore, N in composted litter or litter that
has been exposed to the weather for several months is less
available to the crop. The moisture content of composted
litter is generally around 40 percent compared to 20 percent
in fresh litter. Composting also reduces its value. Composted
litter may have a fertilizer grade of 1.5-3-1 compared to a 3-3-2
for fresh litter.
Composts. Composted dead birds from a broiler
operation have about the same nutrient concentration as fresh
litter on a fresh weight basis. A survey of 30 composters in
Alabama found an average moisture of 36 percent. On a fresh
weight basis, the average fertilizer grade of the secondary
compost was 2.4-2.6-1.6 (48-52-32 pounds N-P2
O5-K2O per ton).
Odors. To conserve N in poultry manure
and to reduce ammonia odor and associated N loss,
superphosphate can be applied at the rate of 100 pounds
per ton of manure in the house. The phosphate will trap
the ammonia as ammonium phosphate. However, the
increased P in the litter may not be needed by the crop.
Lime. Hydrated lime (calcium hydroxide)
will help dry out litter, reduce fly problems, and maintain
good litter condition. However, it will also increase ammonia
volatilization and N loss. Do not use it when the ammonia level
in the house is high. Use lime at the rate of 50 pounds per 1,000
square feet of floor space.
Never apply agricultural lime to poultry houses!
Litter Disposal. Where excess quantities of
manure must be disposed on the land
chose a cropping system to maximize N uptake. Row crops are
poor users of soil N because of a limited root system. Corn or
cotton may take up only 50 to 60 percent of the N applied. Grasses,
such as hybrid bermudagrass and bahiagrass, produce large amounts
of dry matter and are efficient N users. As much as 90 percent of the
applied N could be recovered by a good bermudagrass sod. Cool
season grasses such as fescue and ryegrass are not as efficient
because most of their growth is in the early spring. Harvest
excess forage frequently to remove N from the land. These
practices will minimize potential surface and ground water
contamination from excess N applied in manure.
Liming Value Of
Poultry Manures And Broiler Litter. Because
layers are fed ground limestone, the manure has some liming
value. Even broiler litter may increase the soil pH slightly.
However, layer manure and broiler litter should be applied for
its nutrient value. Monitor soil pH with routine soil testing
and apply additional agricultural lime if needed.
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