Table 12.1
Typical Manure Characteristics
Dairy Cow
Beef Cow
Chicken
Hog
DRy MATTER CONTENT (%)
Solid
26
23
55
9
Liquid (fresh, diluted)
7
8
17
6
TOTAL NUTRIENT CONTENT (APPROxIMATE)
Nitrogen
pounds/ton
10
14
25
10
pounds/1,000 gal ons
25
39
70
28
Phosphate, as P2O5
pounds/ton
6
9
25
6
pounds/1,000 gal ons
9
25
70
9
Potash, as K2O
pounds/ton
7
11
12
9
pounds/1,000 gal ons
20
31
33
34
Approximate amounts of solid and liquid manure to
supply 100 pounds N for a given species of animal*
solid manure (tons)
10
7
4
10
liquid manure (gal ons)
4000
2500
1500
3600
*Provides similar amounts of nutrients.
Source: Modified from various sources.
allows the farmer the opportunity to apply manure
cHEMIcAl cHARAcTERISTIcS OF MANURES
when it’s best for the crop and during appropriate
A high percentage of the nutrients in feeds passes right
weather conditions. This reduces nutrient loss from the
through animals and ends up in their manure. Depending
manure, caused by water runoff from the field. However,
on the ration and animal type, over 70% of the nitrogen,
significant losses of nutrients from stored manure also
60% of the phosphorus, and 80% of the potassium fed
may occur. One study found that during the year dairy
may pass through the animal as manure. These nutrients
manure stored in uncovered piles lost 3% of the solids,
are available for recycling on cropland. In addition to the
10% of the nitrogen, 3% of the phosphorus, and 20% of
nitrogen, phosphorus, and potassium contributions given
the potassium. Covered piles or well-contained bottom-
in table 12.1, manures contain significant amounts of
loading liquid systems, which tend to form a crust on the
other nutrients, such as calcium, magnesium, and sulfur.
surface, do a better job of conserving the nutrients and
For example, in regions that tend to lack the micronutri-
solids than unprotected piles. Poultry manure, with its
ent zinc, there is rarely any crop deficiency found on soils
high amount of ammonium, may lose 50% of its nitro-
receiving regular manure applications.
gen during storage as ammonia gas volatilizes, unless
The values given in table 12.1 must be viewed with
precautions are taken to conserve nitrogen. Regardless
some caution, because the characteristics of manures
of storage method, it is important to understand how
from even the same type of animal may vary consider-
potential losses occur in order to select a storage method
ably from one farm to another. Differences in feeds,
and location that minimize environmental impact.
mineral supplements, bedding materials, and storage
131
Building SoilS for Better CropS: SuStainaBle Soil ManageMent