Manure collection occurs away from the animals to
provide a clean living area for the animals. Manure falls
through small openings in the flooring into the collection
tank, where manure may be stored, flushed or scraped.
Lagoons provide a source of recycled water for flushing so
that clean, potable water does not have to be used for
flushing manure out of the building or pen area.
Southern portions of the United States use lagoon systems,
treating the manure for odor control. Midwest
regions use many types of manure systems, including
lagoons, but slurry systems are predominant. |
What are lagoons
and slurry storage systems?
Slurry systems are
glass-lined steel, concrete or earthen structures that serve
as storage for manure and wastewater from animals. The
concrete structures are often built under the hog building.
External tanks are sometimes covered. The manure in slurry
systems is agitated before it is applied to land, and all
the manure is applied every year.
Advantages of a slurry system include greater retention of
manure nutrients and less total volume of manure to handle.
Nutrients also exist in a more concentrated form. However,
slurry storage structures may be more costly than lagoons.
Lagoon systems are larger clay- or plastic-lined earthen
structures that act as digesters and as storage structures
for manure. As manure enters a lagoon, the solids settle to
the bottom where bacterial activity is promoted to break
down many of the solids in the manure.
Liquid manure typically is pumped from the top of lagoons,
and contains low nutrient concentrations leaving the
nutrient-rich sludge on the bottom of the lagoon. Lagoons
have larger surface areas than slurry tanks because of the
sloped sides of the earthen structure and the need to treat
and store manure and waste water. The majority of the
nutrients entering a lagoon are retained in the sludge or
lost to the atmosphere.
Advantages of lagoon systems include lower construction
costs and beneficial bacterial degradation of manure solids.
They also provide a source of recycled water for flushing
manure from barns.
Disadvantages include some loss of the nutrient nitrogen
through the air, difficulty in removing nutrient-rich sludge
from the bottom of the lagoon and odors associated with
anaerobic degradation of manure solids. |
