IATP Hog Report - Institute for Agriculture and Trade Policy

Section 3
Receiving minimal day-to-day employee attention and requiring minimal
capital structure, open-air, earthen storage basins or lagoons and aerial
spraying onto nearby crop or pastureland add significantly to the economy
of industrialized farming. In hot, dry climates, lagoons may be allowed to
fill with animal waste indefinitely under the theory that the liquids and
solids will separate and the liquid, rising to the top, will evaporate.
Eventually, however, the sludge that accumulates at the bottom rich with
phosphorus and containing heavy metals must be disposed of in some way.
What's Wrong With Liquefied Manure?
The intentional mixing of water and animal wastes is proving to be one of
the great mistakes of modern technology. The practice facilitates the
housing of thousands of large animals on very little land. The accumulated
sewage creates health concerns, as does sewage from human cities, but
unlike human sewage, treatment of animal waste is not required by law.
The liquefied hog manure from animal factories contains the nutrients
nitrogen, phosphorus, potassium, calcium, and magnesium (common to all
manures) along with heavy metals such as cadmium, zinc, and copper
(copper sulfate is added to the diets of hogs to promote growth). 4 In
amounts that are easily taken up by crops, nitrogen, phosphorus, and
potassium are important soil nutrients that contribute to the healthy growth
of crops. In excess, they create pollution and health problems. 5
Nitrates are formed from the organic nitrogen contained in manure. These
dissolve in water and can move through the soil into groundwater. 6 A high
nitrate content in drinking water may cause methemoglobinaemia, or bluebaby
disease, where the blood's oxygen-carrying capabilities ise
drastically reduced in infants that drink nitrate contaminated drinking
water, leading to develop-mental deficiencies and, in severe cases, death. 7
In many parts of the nation, the soil is receiving too much phosphorus.
Growing corn requires a ratio of about six parts nitrogen to one part
phosphorus, while there is only about 1.5 parts nitrogen for one part
phosphorus in liquid hog waste. 8 Applying liquid manure in excess of a
crop's phosphorus requirements results in a buildup of soil phosphorus.
Phosphorus is transported to surface water by eroding soil particles and
runoff. In surface waters phosphorus contributes to algae proliferation 9
and surface water degradation.
Heavy metals can damage the fertility of soil and may poison grazing
animals. Metal pollution is virtually irreversible and has a greater toxic
potential on grassland than on crops. 10 Grazing animals tend to ingest soil
from the surface, which is how they can absorb metals.
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