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What is sustainability
and why does it matter?
One way to start exploring this crucial topic is to picture
a fish tank. Keeping its occupants alive takes work. Besides
feeding the fish each day, an aquarium owner must make sure
the pump, filter, and heat lamp are working. Fish tanks also
require regular cleaning. These actions are essential for
sustaining life in the aquarium. If the owner neglects the
aquarium, the fish will die. It's that simple.
Source: National Oceanic and Atmospheric Administration |
Like a fish tank, Earth is a closed system. But unlike fish,
we can make decisions about our impact on the system in which
we live. Our survival on this planet, in fact, depends on
facing two inescapable realities:
- We can't add anything. Our "aquarium" has a finite
amount of matter—soil,
rock, water, and so forth. Besides energy from the sun,
whatever we produce or consume comes ultimately from materials
on the planet. If we use up something—oil supplies,
for instance—there's no way to get more.
- We can't subtract anything. We talk about throwing
things away as a solution, but there's really no "away"
in our global ecosystem. Matter may change form, as when
fire turns solids into gases. But nothing truly disappears.
If we create pollution that natural forces can't break down,
we're stuck with the mess.
Sustainability is living in a way that keeps our "aquarium"
in good shape. It means using resources wisely, allowing nature
to replenish itself, and cleaning up after ourselves. It means
meeting the needs of the present without compromising the
needs of future generations. This may sound like idealistic
ecospeak. But it's actually the only realistic long-term way
to preserve our habitat—and our health.
Fortunately, many natural processes help keep the Earth
healthy. Bacteria and other microorganisms decompose organic
wastes. Trees and plants consume carbon dioxide and create
oxygen. But humanity now produces more waste than such natural
systems can handle. We've also created dangerous substances
that break down extremely slowly—or not at all. These
actions threaten the planet's long-term health. In other words,
they're unsustainable.
FOOLHARDY FARMING
Modern agriculture offers many examples of unsustainable
human actions. We are losing soil and using water much faster
than nature can replace them. We are also using pesticides,
fertilizers,
and other substances in amounts that far exceed nature's ability
to decompose or assimilate them. And the trend of focusing
on a small number of cash
crops has led to what scientists call genetic
erosion.
No other species would purposely spoil its own environment.
Here are a few ways that we are affecting our resources:
- SOIL: Farming techniques, such as planting the
same crop year after year or planting on steep slopes, can
significantly increase the likelihood of erosion. As a result,
wind and water can carry off tons of valuable topsoil. Replacing
even a centimeter-thick layer can take up to 1,000 years,
depending on the location.
- WATER: Forty percent of the world's food comes
from irrigated crops. To get water for irrigation, we are
emptying surface aquifers much faster than nature can refill
them. We're also tapping deep, underground aquifers in ways
that either nature can't replace or can do so only slowly.
Each year, for instance, one must go a meter deeper to reach
the Ogallala aquifer, which is crucial to farming in the
midwestern U.S.
- ENERGY: Industrial agriculture relies on heavy
machines, which guzzle huge quantities of irreplaceable
fossil fuels. Processing and shipping modern food products
also requires large amounts of energy. Many pesticides and
fertilizers, moreover, include petroleum-based ingredients.
This extravagant approach to using up Earth's resources
should make us stop and think. Is our current food production system really sustainable? Many scientists warn that it isn't.
TIME FOR ANOTHER
APPROACH?
"Insanity," the old saying goes, "is doing the same thing
over and over again, and expecting different results." With
that in mind, some agricultural experts say it's time for
a whole new approach to farming. They advise shifting from
industrial
agriculture to sustainable
agriculture. The chart below illuminates the two approaches.
|
Industrial Agriculture |
Sustainable Agriculture |
| VISION:
Farming is a commercial activity, and agricultural technology
helps us overcome nature. |
VISION:
Farming is a way of life, and working with nature is the
best approach. |
SOIL:
Fields are like factories—a place to produce something.
Fertilizers can replace any nutrients lacking in unhealthy
soil. Deep plowing breaks up soil and leaves it vunerable
to erosion.
|
SOIL:
Fields are home to an intricate biological community,
including crops, bugs, and microbes. Careful choices are
needed to keep soil healthy. In no-till or low-till methods,
earthworms and deep-rooted plants can break up soil.
|
| CROP CHOICE:
Monoculture, or growing a single crop, is more efficient
than raising different types of plants or rotating them.
Government programs can dictate what crops are grown.
High-yield crops earn farmers the highest income. |
CROP CHOICE:
Rotating crops replenishes soil. Polyculture, a mix of
crops, benefits from symbiotic relationships among species.
Choosing crops that suit the climate reduces irrigation
and risk of disease. |
| CROP TRAITS:
Produce growers prize varieties that ship well, have a
long shelf life, look good, and appeal to mass market
consumers. |
CROP TRAITS:
Farmers stress taste and adaptability to local conditions
in selecting plants to raise. Farmers often sell locally. |
| FERTILIZER:
Large doses of synthetic products not produced by the
plants or animals already on the farm provide nitrogen,
phosphorus, and potassium (N-P-K). |
FERTILIZER:
Farmers pay attention to soil biology and minerals already
in the ground, which lessens the need for synthetic fertilizers. |
| PEST CONTROL:
Synthetic pesticides, often used in large amounts, kill
far more than the targeted pests, which often grow resistant
to the chemicals. This can create new and worse problems.
Farmers turn to genetically-modified seeds that resist
disease. |
PEST CONTROL:
Farmers seek ecology-based, nontoxic remedies. These may
include introducing companion planting (growing a plant
that repels another plant's pests) or insects that
will eat pests. |
| WATER:
Irrigation moves large amounts of water to high-yield
crops. This often "mines" aquifers, which
aren't replenished by rainfall. Salinization further
destroys farmland. |
WATER:
Farmers use drought-resistant plants and crops that shade
soil, reducing evaporation of water from the soil. |
| POVERTY:
Corporations, trade regulations, and other government
policies impoverish farmers in developing countries, who
turn to slash-and-burn farming that harms the soil. |
POVERTY:
Fair competition helps even poor farmers find a market
for their crops. |
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| Contour plowing and cows grazing freely reflect sustainable agricultural methods. Source: USDA Sustainable Agriculture Research & Education (SARE) Program |
STEPPING TOWARD SUSTAINABILITY
Advocates of sustainable farming offer various suggestions
for growing food in an environmentally sound way.
- Rotating crops each year can reduce the need for chemical
fertilizers. That's because different plants use different
soil nutrients. Some crops actually put nitrogen—an
important nutrient—back into the soil. This is called
nitrogen fixation.
- By recognizing the life cycle of pests, crop rotation
can lessen or eliminate farmers' reliance on commercial
pesticides.
- Plowing less often, or not at all, minimizes erosion
and helps keep topsoil in a healthy, natural state with
diverse population of organisms.
Sprouting amid the remains of old wheat plants,
these soybeans exemplify two forms of sustainable agriculture:
crop rotation and no-till farming. Source: Natural Resources
Conservation Service |
- Growing a variety of crops limits the extent to which
disease, pests, or price drops can wipe out a farmer's income.
- Periodically moving cattle and other livestock from field
to field (a practice called rotational grazing) gives land
a chance to recover from the animals' grazing and is a natural
way to spread manure. Moving within the same field helps
keep animals disease-free, and reduces the risk of meat
or milk contamination (as with Mad Cow disease).
SIGNS OF HOPE
Agriculture is a huge industry, so changing it may seem
impossible. Yet many farmers around the world are choosing
to raise food in more sustainable ways. A few encouraging
examples:
- More and more farmers have adopted low-till or no-till
methods. The amount of U.S. farmland tilled in earth-friendly
ways rose from 15 percent in 1980 to 35 percent in 1993.
Their pioneering role in farm conservation brings sober pride to South Carolinians. Source: Natural Resources Conservation Service |
- As a result to such practices, the USDA claims that the
topsoil erosion rate for an average American farm dropped
from 7.3 tons a year in 1982 to less than 5 tons in 1997.
- Many farmers report that they were using far fewer chemical
pesticides than before. Organic food sales in the U.S.alone
rises significantly each year.
- More countries are labelling food products to help us
make important choices.
Such improvements are a start, yet a widespread embrace
of sustainable agriculture remains a distant goal. Individuals
and governments must care enough to make changes.
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These are just a few of the books that have
spurred people to take a fresh look at our
choices, our lives, and our impact on the
Earth.
