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Environmental Degradation
All the
facts and comments listed below represent a check list of environmental
degradation of the natural environment where it comes in contact
with the farm, farm practices and farming policies.
Farming
Techniques
Bare Soil
Soil needs
to be covered with plants in order for it to stay intact. Contemporary
farming practices tend to leave the soil barren and open to weathering
from wind and rain for part of the year (usually this occurs during
the winter in Ontario). Up until a few years ago, an average of
3000 million tonnes of topsoil was lost from North American farms
each year. Prince Edward Island, for example, has already lost
half of its topsoil since 1900. A lack of productive soil will
mean a greater reliance on commercial fertilizers to produce our
food.
Row Crop
Monoculture
Modern row
crop monoculture (growing one species or strain of plant over
a wide area) relies heavily on chemicals to control pests. These
chemicals are usually synthetic organic substances and they find
their way into the food chain via the water which runs off the
agricultural land. Through this runoff, these synthetic compounds
get into the natural food chain with unforeseeable consequences.
The first pesticide to be recognized as causing a problem was
DDT. It is no longer used, but other pesticides such as dieldrin
continue to persist in fish at relatively high levels. Pesticides
kill more than the target pest. These chemicals usually become
concentrated in the fat of animals which eat the insects, and
then move up the food chain in ever greater concentrations. Also,
when sprayed in an area with high winds they can be carried for
a considerable distance.
Commercial
Fertilizers
On the farm,
commercial fertilizer is spread on soil to increase the growth
of crops. Unfortunately, not all applied fertilizer is used or
made available to the plants. Nitrates and phosphates which are
not absorbed make their way into surface water, causing serious
environmental problems for plants and animals which depend on
this water.
Irrigation
Irrigation
of crops accounts for 70% of the world's water consumption. Countries
including Pakistan, Egypt, Iraq, India and the U.S.A. are all
experiencing soil salinization resulting from irrigation. As the
salt level of the soil increases, the crops cannot grow well.
New salt resistant crops must then be genetically developed. This
is an endless cycle. One percent of Canada's total farmland is
irrigated.
Clearing
of the Rainforest
Rainforest
is being cleared in much of South America so that ranchers can
produce cheap beef for North American consumption. The topsoil,
which has been stabilized by the forests, is quickly weathered
and disappears now that the protective covering is gone. Rainforest
is being cleared in much of the tropics for beef production. However,
the only beef exported from these countries to Canada is that
which is processed and canned. No fresh or frozen beef is allowed
into Canada from South America.
Impact
of Farm Animals
Animal manure
can cause environmental problems in surface water. Nitrates leach
from farms where manure is not stored or spread properly. On some
farms, manure is sometimes spread on frozen fields in the winter.
The water which runs off these fields in the spring is therefore
very high in nitrates and other nutrients.
Ruminants,
cattle in particular, contribute to the Greenhouse Effect. This
is because each of the world's 2 billion cattle produce 400 L
of methane a day as their digestive tract ferments plant material.
Methane, the second largest contributor to the Greenhouse Effect,
is also produced by the decomposition of organic matter, (in swamps
and rice paddies), termite action, car exhaust and fossil fuel
extraction.
Canadian
cattle contribute about 0.025% of the greenhouse effect from methane
emissions in the world. The greatest contributors to the greenhouse
effect appear at this point to be wetlands, rice paddies, biomass
burning, natural gas leaks, industry and fuel combustion. The
amount of greenhouse gas produced by a cow per day is equal to
that produced by a car driving 3.2 km. It is important to note
that since we import beef from the U.S.A. and South America, we
are responsible for a much higher percentage of the global methane
gas production, as well as for the destruction of the rain forests,
on the ashes of which the cattle now graze.
Impact
of Chemicals
The growth
of crops takes carbon dioxide (the leading greenhouse gas) from
the air and produces oxygen. An average acre of farmland (a hectare
is roughly equal to 15 city lots), producing 7.5 t of corn, will
use 15-17 t of carbon dioxide, and return 12-15 t of oxygen to
the atmosphere. Canada's corn crop alone generates enough oxygen
for all Canadians each year. The crop does not, however, use up
all the greenhouse gasses we produce. In fact, most of the carbon
dioxide which is absorbed is eventually returned to the atmosphere
when the corn is "burned" in the respiration process
by humans and other animals.
Phosphates
from fertilizers and animal waste lead to the stagnation of water
supplies by promoting the growth of algae (eutrophication). This
algal growth uses up the available oxygen.
Nitrates
from the same sources as the Phosphates are converted by bacteria
in the intestinal tract of animals to nitrites which will then
prevent the body from properly taking up oxygen. Young animals
(including humans) are particularly at risk when consuming water
high in nitrates. Nitrites are also linked with cancer.
Insects
and weeds have become resistant to many pesticides over the years
so that greater quantities have to be applied in order to have
the same effect. Over 2 million tonnes of pesticide are used throughout
the world each year. Third World countries with less than 15%
of the world pesticide consumption suffer 50% of poisonings and
75% of the deaths resulting from improper pesticide handling.
Solutions
Protecting
Farmland
Farmers
protect the quality of farmland in many ways including:
- Crop
residues such as stalks and leaves are left standing in the
fields over winter, to reduce wind and water erosion;
- Clover
and other green legumes are plowed into the soil, to improve
fertility and increase organic matter, preventing soil compaction;
- Some
crops are now planted directly in unworked land, without tillage,
reducing both soil erosion and fuel consumption;
- Crops
are rotated frequently so that one crop is not grown on one
field year after year. This not only improves the soil structure
and fertility, but it also reduces pests and plant diseases,
resulting in less of a need for pesticides;
- Surplus
feed grains unsuitable for human use are a major source of feed
for cattle, pigs and poultry. Animals also consume agricultural
by-products such as corn stalks and leaves, oilseed meal and
wheat hulls. Leftovers from food processing and canning factories,
and even restaurants, can be combined with other feeds to provide
a nutritious diet for farm animals. Farm animals provide fur,
feathers and down, leather, bristles, and bones, fats, oils
and gelatins for food and industrial processes, as well as countless
medical and pharmaceutical products. The cost, in dollars and
environmental damage, is reduced if more, or all of the animal
is used for various purposes.
Grazing
or Restoring
About 30%
of Canada's farmland is not considered to be economically or environmentally
suitable for cultivation but supports sustained ruminant livestock
grazing. If this land were not grazed it could not produce food.
However, there is a question as to whether we would be better
suited by letting this land return to natural forces so that it
might someday approximate its former natural state.
Manure
Technology
Farmers
should test their soils regularly and apply only the fertilizers
(both commercial and manure) their crops require. To apply too
much at the wrong time or in the wrong way is both a waste of
money and an environmental hazard. New storage systems and manure
spreaders, although costly, are helping farmers get the maximum
value from the manure their livestock produce. With proper management,
the need for commercial fertilizers is dramatically reduced. In
fact, many farmers have completely eliminated the need for commercial
fertilizer by managing their animal's manure more effectively.
Some farmers
actually collect the methane from fermenting animal and farm wastes.
The gas can be pressurized and used for powering farm equipment
and heating animal enclosures. This process not only saves fuel
costs, but it breaks down the methane into slightly less destructive
greenhouse gases, mainly carbon dioxide.
Organic
Options
Pesticide
use is stringently controlled in Canada to prevent environmental
damage, though there is a question as to whether the controls
are enough. Modern pesticides play an important role in dramatically
reducing crop losses caused by weeds, plant diseases and insect
pests. Many farmers are abandoning pesticides and fertilizers,
however, in favour of organic methods of improving the soil and
countering weeds, diseases and pests.
Growers
use a combination of traditional and new techniques to minimize
the need for chemical pest controls. Crop rotation, pest-resistant
varieties, and mulches reduce diseases, weeds and insects. Screens
or barriers protect some fruit and vegetable crops, while brightly-coloured
sticky boards trap insects in greenhouses. Mechanical field vacuums
can suck insects from growing plants. Some insects and bacteria
may even help us control pests. Scientists are studying a virus
that could control the coddling moth (a major pest of apples and
pears), and a parasitic fungus that may prevent white mold on
beans, celery and tomatoes.
According
to mainstream farmers, chemical pest controls are still needed.
But careful monitoring and new methods make it possible to spray
less often by timing applications to target vulnerable periods
in the life-cycle of specific pests. In Ontario, for example,
pesticide use was reduced by almost 20% in five years (1983-1988).
The goal is to reduce pesticide use in the province a further
50% by the end of the century.
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