The term "farming" covers the wide spectrum of agricultural practices. On one end of the spectrum is the subsistence farmer, who farms a small area with limited resource inputs, and produces only enough food to meet the needs of his/her family. At the other end is commercial intensive agriculture, including industrial agriculture. Such farming involves large fields and/or numbers of animals, large resource inputs (pesticides, fertilizers, etc.), and a high level of mechanization. These operations generally attempt to maximize financial income from grain, produce, or livestock.
Modern agriculture extends well beyond the traditional production of food for humans and animal feeds. Other agricultural production goods include timber, fertilizers, animal hides, leather, industrial chemicals (starch, sugar, ethanol, alcohols and plastics), fibers (cotton, wool, hemp, and flax), fuels (methane from biomass, biodiesel), cut flowers, ornamental and nursery plants, tropical fish and birds for the pet trade, and both legal and illegal drugs (biopharmaceuticals, tobacco, marijuana, opium, cocaine).
The twentieth century saw massive changes in agricultural practice, particularly in agricultural chemistry and in mechanization. Agricultural chemistry includes the application of chemical fertilizer, chemical insecticides (see pest control), and chemical fungicides, soil makeup, analysis of agricultural products, and nutritional needs of farm animals. Up to and including the 1970s, surface runoff of fertilizer and pesticides was a growing and uncontrolled problem. Staring roughly in 1980, many Western nations, prodded by dozens of environmental action groups, began to implement effective controls on agriculture-related pollution, and the green revolution spread many of the benefits of agricultural chemistry to farms throughout the world, without the extreme pollution that originally accompanied them. Mechanization has also enormously increased farm efficiency and productivity in most regions of the world, especially in the form of the tractor and various gins (short for "engine") like the cotton gin, semi-automatic balers and threshers (see agricultural machinery).
Other recent changes in agriculture include hydroponics, plant breeding, hybridization, gene manipulation, better management of soil nutrients, and improved weed control. Genetic engineering has yielded crops which have capabilities beyond those of naturally occurring plants, such as higher yields and disease resistance. Modified seeds germinate faster, and thus can be grown in an extended growing area. Genetic engineering of plants has proven controversial, particularly in the case of herbicide-resistant plants.
Engineers may develop plants for irrigation, drainage, conservation and sanitary engineering, particularly important in normally arid areas which rely upon constant irrigation, and on large scale farms.
The packing, processing, and marketing of agricultural products are closely related activities also influenced by science. Methods of quick-freezing and dehydration have increased the markets for farm products (see food preservation and meat packing industry).
Animals, including horses, mules, oxen, camels, llamas, alpacas, and dogs, are often used to cultivate fields, harvest crops and transport farm products to markets. Animal husbandry not only refers to the breeding and raising animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis, but the breeding and care of species for work and companionship.
Airplanes, helicopters, trucks, tractors, and combines are used in Western agriculture for seeding, spraying operations for insect and disease control, harvesting, aerial topdressing and transporting perishable products. Radio and television disseminate vital weather reports and other information such as market reports that concern farmers. Computers have become an essential tool for farm management.
Ploughing rice paddies with water buffalo, in
Indonesia.
According to the
National Academy of Engineering in the
United States, agricultural mechanization is one of the 20 greatest engineering achievements of the 20th century. Early in the century, it took one American farmer to produce food for 2.5 people. Today, due to advances in agricultural technology, a single farmer can feed over 130 people.
[2] This comes at a cost, however. A large energy input, often from
fossil fuel, are required to maintain such high levels of output.
In recent years, some aspects of intensive
industrial agriculture have been the subject of increasing discussion. The widening
sphere of influence held by large seed and chemical companies, meat packers and food processors has been a source of concern both within the farming community and for the general public. Another issue is the type of feed given to some animals that can cause
bovine spongiform encephalopathy in cattle. There has also been concern because of the disastrous effect that intensive agriculture has on the environment. In the US, for example, fertilizer has been running off into the Mississippi for years and has caused a
dead spot in the Gulf of Mexico, where the Mississippi empties. Intensive agriculture also depletes the fertility of the land over time, potentially leading to
desertification.
A field of ripening
barley
The patent protection given to companies that develop new types of seed using
genetic engineering has allowed seed to be licensed to farmers in much the same way that computer software is licensed to users. This has changed the balance of power in favor of the seed companies, allowing them to dictate terms and conditions previously unheard of. The
Indian activist and scientist
Vandana Shiva argues that these companies are guilty of
biopiracy.
Soil conservation and
nutrient management have been important concerns since the 1950s, with the most advanced farmers taking a
stewardship role with the land they use. However, increasing contamination of waterways and wetlands by nutrients like
nitrogen and
phosphorus are concerns that can only be addressed by "enlightenment" of farmers and/or far stricter
law enforcement in many countries.
Increasing consumer awareness of agricultural issues has led to the rise of
community-supported agriculture,
local food movement, "
Slow Food", and commercial
organic farming.
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