 In a healthy farm system, agriculture works in harmony
with the natural environment. This begins with healthy
soil that stores water and nutrients and provides a
stable base to support plant roots. In a sustainable
system, soil is kept in balance. Crops are rotated through
the fields to replace nutrients in the soil. Where there
is livestock, animals graze the land, then waste from
those animals is used to fertilize the soil. The idea
is that as farmers take from the land they also give
back.
Industrial farms disregard that need for balance. Land
is used continuously and not given proper rest. Crops
are not rotated in a way that replenishes the soil.
Manure and chemical fertilizers are used to “feed”
the soil, but through over-application these additives
become a problem.
Animal Manure
Factory farms concentrate an unnatural number
of animals in one place, which creates an unmanageable
amount of waste. For example, a single hog excretes
up to 17.5 pounds of manure and urine each day. Put
1,000 hogs together, and that’s six million pounds
of waste each year. On a factory farm containing 35,000
hogs, over four million pounds of waste are produced
each week, and over 200 million pounds each year. i
Whereas on a sustainable farm animal waste can be a
tool, in factory-farm amounts it becomes a major pollutant.
The creation and disposal of such enormous quantities
of waste has a devastating effect on the air, water
and soil surrounding factory farms. Unlike human waste,
livestock manure is not processed for sanitation. On
factory farms it is commonly mixed with water and held
in pits (called “lagoons”), and then spread
or sprayed on cropland. But the system often suffers
from an excess of manure: the lagoons can leak or spill,
for instance, or the manure is over-applied to fields,
which can cause it to run off into surface waters.
Pollutants
Manure carries with it other substances that
are used on industrial farms. These include antibiotics
and artificial growth hormones,
which contaminate waterways and affect the plants and
animals that live in them. ii Salt, a common
component of manure from industrial dairies, can damage
soil quality and contributes to erosion. iii
Nutrients and heavy metals present in animal feed are
also excreted by livestock, and so end up being applied
to cropland. These include zinc, copper, chromium, arsenic,
cadmium and even lead. iv In balanced amounts,
some of these elements can be good for soil and promote
plant growth. But as factory farms over-apply manure
to fields, a significant quantity of nutrients builds
up in the soil and can actually reduce the soil’s
fertility. v This damage is difficult to
reverse, and ultimately puts fertile cropland out of
use. vi
Air and Water Pollution
Factory farms emit harmful gases and particles
such as methane and hydrogen sulfide, which can contribute
to global warming and harm the health of those living
or working nearby. Air pollution
results from the overuse of machinery, the mismanagement
of manure, and the irresponsible feeding practices that
characterize industrial farming.
Chemical fertilizers and pesticides have turned agriculture
into a leading source of water
pollution in the United States. Runoff from factory
farms kills fish, degrades aquatic habitats and threatens
drinking water supplies. Additionally, factory farms
use tremendous amounts of water, which cuts into our
precious supplies of water that are not contaminated.
Feed Crops
Factory farms also harm American farmland through
their consumption of massive quantities of feed crops.
Consider this: The average cow eats roughly 30 pounds
of food each day. viii The beef industry
raises more than 30 million cows each year. ix
Some of those cows feed themselves by grazing on pasture,
but the vast majority are raised in feedlots, where
they eat corn and soybeans. The result: American cropland
is pushed hard to produce an extraordinary amount of
grain.
In response to this demand, conventional crop producers
have adopted intensive growing practices. These methods
increase crop yields, but they also damage the soil
and throw natural systems out of balance, primarily
due to erosion and loss of fertility.
Crop farming is an ”extractive” process,
meaning that as plants grow, they take nutrients from
the soil and turn it into plant matter. When the plants
are harvested, the nutrients leave the soil’s
system. Sustainable practices replenish these nutrients,
using compost, manure, or “green manures,”
which are plants that naturally deposit nutrients in
the soil. Instead of replenishing the soil, intensive
practices use chemical fertilizers to supply only what
is necessary to grow the next round of crops.
Chemical fertilizers are not as effective as natural
sources of fertility, and are known to cause long-term
depletion of organic matter, soil compaction, and degradation
of overall soil quality. x In 2005, American
farmers used more than 22 million tons of chemical fertilizers.
xi
Tilling is another aspect of farming that has gone
out of balance in industrial practice. When land is
plowed, old organic matter is turned under the soil
in order to plant a new crop. However, when soil is
bare it is most susceptible to erosion. xii
There are many ways to protect against this. Farmers
can leave strips of land untilled, to act as a catch
for water-borne erosion. Instead of plowing up and down
hills, leaving furrows that carry wet soil straight
downhill, they can plow with the contours, making furrows
that act as tiny retaining walls. And they can grow
cover crops in the off-season, whose plants anchor the
soil with their roots.
In the drive to produce ever more grain, however, precautions
like these are often not taken. Currently, the
average rate of soil erosion on US cropland is seven
tons per acre per year. xiii This is a serious
problem, because erosion causes fertile farmland to
lose nutrients and water retention ability. Because
the first thing to go is precious topsoil, the soil
removed by erosion contains about three times more nutrients
and 1.5 to five times more organic matter than that
which remains behind. xiv The National Sustainable
Agriculture Information Service writes that erosion
is the single greatest threat to soil productivity in
the United States. xv
Sustainable Alternatives
By using farming techniques such as crop rotation,
conservation tillage, raising animals on pasture and
natural fertilization, sustainable farmers produce food
without having a negative effect on the environment.
Instead of harming soil, air and water, sustainable
farms actually enhance and preserve the land so that
future generations can continue to use it for food production.
What You Can Do
By supporting small, sustainable farms you can
help reduce the impact of industrial farming and promote
the use of environmentally friendly farming methods.
- Visit the Eat
Well Guide to find stores, farms and restaurants
that supply sustainable meats and produce.
- Ask your local farmer about the
erosion prevention techniques and fertilizers used
on his or her farm, and buy your food from farmers
that use conservation tillage and natural fertilizers.
- Plant your own garden, and try
making your own organic fertilizer using a compost
bin. Find out how to compost at HowToCompost.org.
Did You Know?
- In the United States, approximately
40 percent of all chemical fertilizers used eventually
break down into ammonia and are released into the
atmosphere.xvi
- The EPA reports that the waste
generated by animal agriculture has polluted over
35,000 miles of river in 22 states. xvii
- Researchers from the Department
of Economics at the University of Essex put the annual
cost of environmental damage caused by industrial
farming in the United States at $34.7 billion. xviii
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