Monoculture is the practice of planting large tracts of land
with the same crop year after year. It is an efficient method of producing
food but requires mechanized farming and the use of agricultural chemicals
Fossil fuels are necessary in mechanized farming for tilling,
planting, harvesting, and pumping irrigation water. Energy is also needed
to manufacture fertilizers and pesticides.
Pesticides are commonly used in mechanized agriculture because
planting the same crop repeatedly encourages the growth of insect and fungus
pest populations that develop in response to the huge food supply at their
disposal.
Fertilizers are used in mechanized farming because the lack
of crop rotation depletes certain essential soil nutrients. A problem associated
with fertilizer use is increased nutrients in waterways which leads to increased
aquatic plant growth.
Persistent pesticides are stable chemical compounds which
are long-lasting in the environment. They can be applied once and be effective
for a long time, but tend to accumulate in the soil and in nontarget organisms.
Nonpersistent pesticides decompose to harmless products in a few hours or
days and do not accumulate in the environment. They are disadvantageous because
they require more applications.
Biomagnification is the phenomenon of acquiring increasing
levels of a substance in the bodies of higher trophic-level organisms.
Organic farms produce crops without using pesticides and chemical
fertilizers. They are willing to accept lower yields because they do not
have to pay for fertilizers and pesticides. Organic farms also receive higher
prices for products that are organically grown.
Nonchemical methods for controlling pests include the use
of natural predators or parasites, the development of resistant crops, the
use of natural pesticides, the modification of farming practices, and the
use of sex attractants.
The advantage of integrated pest management is the decrease
in the amount of pesticides used. The disadvantage is that farmers must make
modifications to their farming technique.
Three uses of food additives include prolonging the storage
life of food, making the food more attractive, and modifying its nutritive
value.
Actions that farmers can use to reduce the effect of pesticides
on the environment include the use of genetically modified crops, organic
farming, and integrated pest management.
