Organic farming is the
process by which crops are raised using only natural methods to maintain
soil fertility and to control pests. The amount of crops produced by conventional farming methods is often larger than that of organic farming. But conventional farming,
with its heavy use of manufactured fertilizers and pesticides
(agrochemicals), has a greater negative effect on the environment. In
comparison, organic farming produces healthy crops while maintaining the
quality of the soil and surrounding environment.
Soil fertility
Soil fertility is a measure of the soil's ability to grow crops and
plants. Fertility is affected by a soil's tilth and the amount of
nutrients it contains. Tilth refers to the physical structure of soil.
Good tilth means that soil is loose and not compacted. It holds a great
amount of water without becoming soggy and permits air to penetrate to
plant roots and soil organisms. It also allows plant roots to grow and
penetrate deeper.
The nutrients in soil are directly related to the soil's concentration
of organic matter (living or dead plants and animals). Plants require
more than 20 nutrients for proper growth. Some of these nutrients are
obtained primarily from the soil, especially inorganic compounds of
nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. In
natural ecosystems, microorganisms (bacteria and fungi) in the soil
break down organic matter, releasing the inorganic nutrients necessary
for plant growth.
In conventional farming, soil tilth is destroyed by the use of heavy
machinery, which compacts the soil. Very little organic material is
added to the soil in conventional farming, decreasing the amount of
nutrients that are naturally produced. Instead, inorganic nutrients are
added directly to the soil in the form of synthetic fertilizers, which
are manufactured from raw materials. These fertilizers are often applied
at an excessive rate. As a result, they pass through the soil to
contaminate groundwater and flow along the surface of soil to pollute surrounding bodies of water, threatening native species.
In contrast, organic farmers try to increase soil fertility by
increasing the organic matter in the soil. They do so by adding the dung
and urine of animals (which
contains both organic matter and large concentrations of nutrients), by
plowing under growing or recently harvested plants (such as alfalfa or clover), or by adding compost or
other partially decomposed plants. These methods rely more heavily on
renewable sources of energy and materials rather than on nonrenewable
materials and fossil fuels.
Managing pests
In agriculture, pests are any living thing that causes injury or disease
to crops. This can occur when insects eat foliage or stored produce,
when bacteria or fungi cause plant diseases, or when weeds interfere
excessively with the growth of crop plants. In conventional farming,
pests are usually managed using various types of pesticides, such as
insecticides, herbicides, and fungicides. In the short term, these
methods can be effective in reducing the influence of pests on crops.
However, the long-term use of these chemicals has been shown to have a
severe effect on the environment.
Words to Know
Fertilizers: Substances added to agricultural lands to encourage plant growth and higher crop production.Organic matter: Any biomass of plants or animals, living or dead.
Pesticides: Substances used to reduce the abundance of pests, any living thing that causes injury or disease to crops.
Tilth: The physical structure of soil.
Organic farmers do not use synthetic, manufactured pesticides to manage
their pest problems. Rather, they rely on other methods. These include
using crop varieties that
are resistant to pests and diseases, introducing natural predators of
the pests, changing the habitat of the crop area to make it less
suitable for the pest, and (when necessary) using a pesticide derived
from a natural product.
Animal husbandry
In conventional farming, livestock animals are generally kept together
under extremely crowded and foul conditions. Because of this, they are
highly susceptible to diseases and infections. To manage this problem,
conventional farmers rely on antibiotics, which are given not only when
animals are sick but often on a continued basis in the animals' feed.
Since the mid-1990s, however, scientists have known that this practice
has led to the development of new strains of bacteria that are resistant
to the repeated use of antibiotics. These bacteria are not only harmful
to the animals but are potentially harmful to the humans who consume
the animals.
Organic farmers might also use antibiotics to treat infections in sick
animals, but they do not continuously add those chemicals to the
animals' feed. In addition, many organic farmers keep their animals in
more open and sanitary conditions. Animals that are relatively free from
crowding and constant exposure to waste products are more resistant to
diseases. Overall, they have less of a need for antibiotics.
Some conventional farmers raising livestock use synthetic growth
hormones, such as bovine growth hormone, to increase the size and
productivity of their animals. Inevitably, these hormones remain in
trace concentrations, contaminating the animal products that humans
consume. Although risk to humans has yet to be scientifically demonstrated,
there is controversy about the potential effects. Organic farmers do
not use synthetic growth hormones to enhance their livestock.
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