Environmental Engineering Reference
In-Depth Information
sprayed on GM crops have increased from 50 in 1980 to 310 in 2008.
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Additional pesticides are then needed as Mother Nature changes in
response to the attack on her plant and animal species and fi nds ways
to combat them. Pesticide use has increased by 383 million pounds since
GE crops were planted by farmers.
The use of GM crops actually increases the need for newer and more
pesticides. As Rachel Carson noted fi fty years ago, we are engaged in a
biowar we cannot win.
Perhaps even more frightening is the harm that pesticide poisons do
to the human body, as I noted earlier in this chapter. The American
Academy of Environmental Medicine has warned that the public should
avoid GM foods. Based on many animal studies, the academy stated that
“there is more than a casual connection between GM foods and adverse
health effects. There is causation.” It is noteworthy that there have been
no clinical trials of any GM crop. As Canadian geneticist David Suzuki
said, “The experiments simply haven't been done and now we have
become guinea pigs. Anyone that says 'Oh, we know that this is perfectly
safe,' I say is either unbelievably stupid or deliberately lying.”
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How Much Food Can We Grow?
Agricultural productivity in the United States has increased at an average
annual rate of 1.6 percent since 1948, and in 2006 it was 152 percent
above the 1948 level.
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Farmers have doubled or tripled the yield of most
major grains in two ways: growing more plants per acre and harvesting
more human food (wheat, corn) or animal feed (corn, soybeans) per
plant. Many farmers now plant 30,000 or more corn seeds per acre,
about three times the planting density common in the 1940s. The farming
tactics of closer spacing, widespread use of artifi cial chemical fertilizers,
irrigation, and pesticides tend to create big plants that grow fast, but
they do not absorb a comparable amount of many soil nutrients. Agri-
culture is basically an effort to move beyond the limits set by nature.
The bounty of increased production has come at the cost of decreased
nutritive value. Food scientists have compared the nutritional levels of
modern crops with historic, and generally lower-yielding, ones.
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Today's
food produces 10 to 25 percent less iron, zinc, protein, calcium, vitamin
C, and other nutrients such as beta-carotene, phosphorous, copper, and
selenium. Today's vegetables are 5 to 40 percent lower in nutritional
value than in our grandparents' day. Plants cultivated to produce higher
yields tend to have less energy for other activities, such as growing deep,
