Agriculture Reference
In-Depth Information
Pesticides
I'm not going to get into detail about the health consequences of pesticide use because
that would take us too far off track. Many of them cause cancer, neurological damage and
other diseases. Pesticides have traveled to all corners of the world, even into the tissues of
penguins on the south pole. The list of negatives goes on and on. What I do want to outline
briefly are a few of their negative effects on the garden, and specifically on the soil.
When I was younger, I spent the better part of a decade maintaining a 9-hole, par-3 golf
course owned by my parents. You can bet I sprayed pesticides. The enemy on the course
greens was a fungus called dollar spot. The main pesticide ingredient was chlorothalonil, a
polychlorinated aromatic that killed the fungus really well for about seven days until I had
to come back and spray more. So yes, I've used pesticides.
Pesticides kill living things. “Cide” means to kill. Herbicides are specifically made to
kill plants, but we're not talented enough to create these poisons to kill only their target
kingdom, so herbicides often kill or at least hurt animals, bacteria and fungi, too. Of course,
bactericides and fungicides and insecticides kill or hurt animals and plants, as well. For ex-
ample, the fungicide I sprayed on the golf course greens was deadly toxic to fish, too.
While these various forms of pesticide work differently, we really can talk about pesticides
as a whole.
The pesticide manufacturers tell us these poisons will be broken down by the microor-
ganisms in the soil. This may be true if we have a healthy, diverse soil food web, but every
time we or our neighbors spray, even those neighbors many miles away, we decrease the
number of healthy, happy microbes until eventually, there are very few of them left to per-
form this important function. Even when it rains, we get unbelievably high doses of pesti-
cides from thousands of miles away.
Many pesticides have indeed done a great job of killing all insects, diseases and weeds
for awhile, sometimes even for decades. Eventually, the predators figure it out and come
back with a vengeance. This time the chemicals don't work as well or at all. In the mean-
time, the pesticides have done a dandy job of terrorizing the soil environment, ensuring that
weeds are the only plants that will grow there and that plant predators are the organisms
that flourish. Using a herbicide just prolongs weed problems. It does not do any of the other
soil improving steps we'll be looking at — in fact, it does the opposite.
We've already seen how microbes are vital to the very existence of the garden, so we
know we don't want to kill them. Plants are also hurt by pesticides to the point where pro-
tein synthesis stops, soluble nitrogen and sugars increase, and predators are invited to dine.
Animals — our fertilizers, our seed dispersers, our pollinators, birds, bees, butterflies and
everyone else — are hurt, too. We know that certain pesticides contribute to colony col-
lapse disorder in bees.
