is a nice way of talking about one of the dirty jobs of raising
livestockgetting rid of animal waste. What do farmers do with
it? The most common practice is to use water to wash the raw waste
out of barns into earthen . A lagoon is a big pit
in the earth, sometimes lined with clay or a plastic liner. When
a lagoon is full, the mixture is pumped out and sprayed onto fields
But the earthen
lagoons arent perfect. Lagoon leaks and ruptures in the lining
can allow waste to slowly seep into underground water sources. Large
spills and lagoon overflows can dump thousands of gallons of waste
directly into surface waterways, resulting in huge fish kills and
environmental damage. The largest spill in Iowa happened on July
16, 1995, on a Hamilton County Farm. One and a half million gallons
of hog manure flowed from an earthen lagoon, through an underground
line, into the South Fork of the Iowa River. That spill
killed nearly 9,000 fish and countless other aquatic life.
What are the
options? One option is to require the construction of cement structures
for manure storage. These structures are less likely to leak or
rupture and are considered to be safer for the environment.
When manure is applied to the land in proper amounts, the nutrients
it contains (nitrogen and phosphorous) help crops grow. The land
can only absorb so much manure and nutrients. So if too much manure
is applied, some of it runs off the land and into waterways. When
manure gets into water, it can cause a variety of problems:
- The nutrients
spur aquatic plant growth, like algae blooms, which in turn can
trigger a condition called hypoxiaa lack of oxygen. The
cycle of algae blooming and decaying sucks up oxygen in the water,
leaving levels of oxygen too low to support aquatic life.
- High levels
of nitrates in drinking water can cause a serious, even life-threatening
condition in children under six months. The condition, called
blue-baby syndrome, prevents babies blood from carrying
the necessary oxygen.
- Manure can
contain disease-causing bacteria that threaten human health. The
most common is , which is routinely tested
for in drinking water.
These act as guidelines for manure application.
- Test the
soil to see what the current nutrient levels are.
- Test the
manure to see what nutrient levels it contains.
- Use only
as much manure as the crop needs and the soil can hold. (That
will avoid soil contamination, crop damage, runoff and contaminated
- Check soil
moisture before applying liquid wastes, and adjust application
rates to avoid runoff. Frozen ground can't absorb liquid and wet
ground can't absorb more liquid.
- To avoid
runoff, do not apply manure to frozen or saturated soils.
- Use raw
or untreated manure to reduce odors and nitrogen losses.