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Agriculture is the process of producing food, feed, fiber and other
desired products by cultivation of certain plants and the raising of domesticated
animals. Agriculture is also known as farming.
Overview
Agriculture includes both subsistence agriculture, which
is producing enough food to meet the needs of the farmer and family (but no more), and also (almost universally in the "developed" nations and increasingly so in
other areas) the production of financial income from cultivation of the land or commercial raising of animals (animal husbandry). Agriculture is the practice -- the
study of these disciplines is called agricultural
science.
Increasingly, besides food for humans and animal feeds, agriculture produces goods
such as cut flowers, ornamental and nursery plants,
fertilizers, animal
hides, leather, industrial chemicals (starch, ethanol, and plastics), fibers (cotton,
wool, hemp, and flax), fuels (methane, biodiesel, biomass), and both legal and illegal drugs (biopharmaceuticals, tobacco, marijuana, opium, cocaine). Genetically
engineered plants and animals produce specialty drugs.
In the Western world, use of improved genetics, better management of soil nutrients, and improved weed control have greatly increased yields per unit area. At the same time, use of mechanization has
decreased labor requirements, releasing most of the populace from intense agricultural labor. The developing world is behind by
Western measures of productivity, because of unavailability of the education, capital and technology base needed to sustain these advances, and usually ecoregion with less optimal climates and soils.
Modern agriculture depends heavily on engineering and technology and on the biological and physical sciences. Irrigation, drainage, conservation, and sanitary engineering—each of which is important in
successful farming—are some of the fields requiring the specialized knowledge of agricultural engineers.
Agricultural chemistry deals with other vital farming concerns, such as the application of fertilizer, insecticides (see
Pest control), and fungicides,
soil makeup, analysis of agricultural products, and nutritional needs of farm animals.
Plant breeding and genetics contribute immeasurably to farm
productivity. Genetics has also made a science of livestock breeding. Hydroponics, a method of soilless gardening in which plants
are grown in chemical nutrient solutions, may help meet the need for greater food production as the world’s population
increases.
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 Processing and Preservation;
Meat Packing Industry).
Mechanization, the outstanding characteristic of late 19th- and 20th-century agriculture, has eased much of the backbreaking
toil of the farmer. More significantly, mechanization has enormously increased farm efficiency and productivity (see Agricultural
Machinery). Animals including horses, oxen, llamas, alpacas, and dogs, however, are still used to cultivate fields, harvest
crops, and transport farm products to markets in many parts of the world.
Airplanes and helicopters are employed in agriculture for seeding, spraying operations for insect and disease control,
transporting perishable products, and fighting forest fires. 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.
Animal husbandry means breeding and raising animals for meat or to harvest animal products (like milk, eggs, or wool) on a
continual basis.
In recent years, some aspects of industrial intensive
agriculture have been the subject of increasing discussion. The widening sphere of influence held by large seed and chemical
companies and meat packers has been a source of concern both within the farming community and for the general public. 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. Some argue these companies are guilty of biopiracy.
Soil conservation and nutrient
management have been important concerns since the 1950s, with the best farmers taking a
stewardship role with the land they operate.
Increasing consumer awareness of agricultural issues has led to the rise of community-supported agriculture, local food movement, slow food, and commercial organic farming, though these yet remain fledgling industries.
History
Determining the origin of agriculture is problematic since it pre-dates the invention of writing. Some authorities insist localized farming took place more than 10,000 years ago, while others believe the
earliest systematic plantings/harvestings took place no more than 7,000 years ago. The practice of agriculture is often used to
distinguish the neolithic period from earlier parts of the stone age. The first crops that humans domesticated included wheat and barley. It is clear that farming was invented at least twice,
probably more often: once in the Fertile Crescent (some say by the
Natufian culture, others say by the Sumerians), once in East Asia, and probably once in Central
America. Most likely, there was a gradual transition from a hunter-gatherer economy to an agricultural one, via a lengthy period when some crops were deliberately
planted, and other foods were gathered from the wild. The reasons for the earliest introduction of farming may have included
climate change. Farming allows a much greater density of population than can be
supported by hunting and gathering.
After 1492, the world's agricultural patterns were shuffled in the widespread exchange
of plants and animals known as the Columbian Exchange. Crops
and animals that were previously only known in the Old World were now transplanted in the New, and vice versa.
Policy
Agricultural policy focuses on the goals and methods of
agricultural production. At the policy level, common goals of agriculture include:
- Food safety: Ensuring that the food supply is free of
contamination.
- Food security: Ensuring that the food supply meets the population's
needs.
- Food quality: Ensuring that the food supply is of a consistent and
known quality.
- Conservation
- Environmental impact
- Economic stability
Methods
Crops
World production of major crops in 2002
In millions of metric tons, based on USDA estimates:
- Maize 624
- Wheat 570
- Rice 381.1
- Cotton 96.5
Paddy rice is rice in its as-harvested state. Milled rice is rice after it is processed to remove the husk
and, sometimes, polish the kernel.
Crop improvement
An agriculural scientist records corn growth
Domestication of plants is done in order to increase yield, disease resistance, drought tolerance, ease of harvest, and to
improve the taste and nutritional value and many other characteristics. Centuries
of careful selection and breeding have had enormous effects on the characteristics of crop plants. Plant breeders use greenhouses
and other techniques to get as many as three generations of plants per year, so that they can make improvements all the more
quickly. Extensive radiation mutagenesis efforts (i.e. primitive genetic engineering) during the 1950s produced the modern commercial varieties of grains such as wheat, corn and barley.
For example, average yields of corn (maize) in the USA have increased from around 2.5
tonnes per hectare (40 bushels per acre) in 1900 to about 9.4 t/ha (150 bushels per acre)
in 2001, primarily due to improvements in genetics. Similarly, worldwide average wheat
yields have increased from less than 1 t/ha in 1900 to more than 2.5 t/ha in 1990. South American average wheat yields
are around 2 t/ha, African under 1 t/ha, Egypt
and Arabia up to 3.5 to 4 t/ha with irrigation. In contrast, the average wheat yield in countries such as France is over 8 t/ha. Higher yields are due to improvements in genetics, as well as use of intensive farming
techniques (use of fertilizers, chemical pest control, growth control to avoid lodging).
[Conversion note: 1 bushel (q) of wheat = 60 pounds (lb) ≈ 27.215 kg. 1 bushel of corn = 56 pounds ≈ 25.401
kg]
Very recently, genetic engineering has begun to be
employed in some parts of the world to speed up the selection and breeding process. The most widely used modification is a
herbicide resistance gene that allows plants to tolerate exposure to glyphosate. A less frequently used but more controversial
modification causes the plant to produce a toxin to reduce damage from insects (c.f. Starlink).
There are specialty producers who raise less common types of livestock or plants.
Aquaculture, the farming of fish,
shrimp, and algae, is closely associated with
agriculture.
Apiculture, the culture of bees, traditionally for honey, increasingly for crop pollination.
See also : botany, List of domesticated plants, List
of vegetables, List of herbs, List of fruit, List of
domesticated animals
Environmental problems
See also
External links
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