{{farming}}
'''Agriculture''' is the production of [[food]], [[fodder|feed]], [[fiber]] and other goods by the systematic growing/harvesting of [[plant]]s, [[animal]]s and other life forms. "Agriculture" is also short for the study of the practice of agriculture – more formally known as [[agricultural science]].
the word agriculture comes from the latin word "agricultura meaning ''field cultivation''
Agriculture encompasses many subjects, including [[aquaculture]], [[cultivation]], [[animal husbandry]], and [[horticulture]]. Each of these subjects can be further partitioned: for example, [[cultivation]] includes both [[organic farming]] and [[intensive farming]], and animal husbandry includes [[ranching]], [[herding]], and [[intensive pig farming]]. Agricultural products include [[fodder]], ([[starch]], [[sugar]], [[alcohol]]s and [[resin]]s), [[fiber]]s ([[cotton]], [[wool]], [[hemp]], [[silk]] and [[flax]]), fuels ([[methane]] from [[biomass]], [[ethanol]], [[biodiesel]]), [[flower|cut flowers]], ornamental and [[Nursery (horticulture)|nursery plants]], tropical fish and birds for the pet trade, and both legal and illegal drugs ([[biopharmaceutical]]s, [[tobacco]], [[cannabis (drug)|marijuana]], [[opium]], [[cocaine]]).
The [[history of agriculture]] is a central element of [[history of the world|human history]], as agricultural progress has been a crucial factor in worldwide [[social change|socio-economic change]]. [[Wealth]]-building and [[militaristic]] specializations rarely seen in [[hunter-gatherer]] cultures are commonplace in agricultural and agro-industrial societies—when farmers became capable of producing food beyond the needs of their own families, others in the [[tribe]]/[[village]]/[[City-state]]/[[nation]]/[[empire]] were freed to devote themselves to projects other than food acquisition.
As of 2006, an estimated 36 percent of the world's workers are employed in agriculture<ref>[[International Labour Organization]] [http://www.ilo.org/public/english/employment/strat/kilm/index.htm Key Indicators of the Labour Market 2007], [http://www.ilo.org/public/english/employment/strat/kilm/download/kilm04.pdf chapter 4] p. 6</ref> (down from 42% in 1996), making it by far the most common occupation. However, the relative significance of farming has dropped steadily since the beginning of [[industrialization]], and in 2006 – for the first time in history – the [[Service (economics)|services]] sector overtook agriculture as the [[economic sector]] employing the most people worldwide. Also, agricultural production accounts for less than five percent of the [[gross world product]] (an aggregate of all [[gross domestic product]]s).<ref>{{cite web |url=https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html#Econ |title=https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html#Econ |accessdate= |format= |work= }}</ref>
==Overview==
[[Image:Clark's Sector Model.png|thumb|right|The amount of workforce dedicated to agriculture tends to decrease]]
Agriculture played a key role in the development of human [[civilization]]—it is widely believed that the domestication of plants and animals allowed [[humans]] to settle and give up their previous [[hunter-gatherer]] lifestyle during the [[Neolithic Revolution]]. Until the [[Industrial Revolution]], the vast majority of the human population labored in agriculture. Development of agricultural techniques has steadily increased agricultural productivity, and the widespread diffusion of these techniques during a time period is often called an [[agricultural revolution]]. A remarkable shift in agricultural practices has occurred over the past century in response to new technologies. In particular, the [[Haber-Bosch]] method for synthesizing [[ammonium nitrate]] made the traditional practice of recycling nutrients with [[crop rotation]] and animal [[manure]] less necessary. Synthetic nitrogen, along with mined [[rock phosphate]], [[pesticides]] and [[Mechanised agriculture|mechanization]], have greatly increased [[crop yields]] in the early [[20th century]]. Increased supply of grains has led to cheaper livestock as well. Further, global yield increases were experienced later in the 20th century when [[high-yield varieties]] of common staple grains such as [[rice]], [[wheat]], and [[corn]] were introduced as a part of the [[Green Revolution]]. The Green Revolution exported the technologies (including pesticides and synthetic nitrogen) of the developed world out to the developing world. [[Thomas Malthus]] famously predicted that the Earth would not be able to support its growing population, but technologies such as the Green Revolution have allowed the world to produce a surplus of food.<ref name="BumperCrop">''New York Times'' (2005) [http://www.nytimes.com/2005/12/08/business/worldbusiness/08farmers.html?_r=1&oref=slogin Sometimes a Bumper Crop is Too Much Of a Good Thing]</ref>
[[Image:2005gdpAgricultural.PNG|thumb|right|Agricultural output in 2005]]
Many governments have subsidized agriculture to ensure an adequate food supply. These [[agricultural subsidies]] are often linked to the production of certain commodities such as [[wheat]], [[corn]], [[rice]], [[soybean]]s, and [[milk]]. These subsidies, especially when done by [[developed country|developed countries]] have been noted as [[protectionist]], inefficient, and environmentally damaging.<ref>''New York Times'' (1986) [http://query.nytimes.com/gst/fullpage.html?res=950DE3DC1730F93BA3575AC0A96F948260 Science Academy Recommends Resumption of Natural Farming]</ref> In the past century agriculture has been characterized by enhanced [[productivity]], the use of synthetic [[fertilizers]] and pesticides, [[selective breeding]], [[Mechanised agriculture|mechanization]], [[water contamination]], and [[farm subsidies]]. Proponents of [[organic farming]] such as [[Sir Albert Howard]] argued in the early 1900s that the overuse of pesticides and synthetic fertilizers damages the long-term fertility of the soil. While this feeling lay dormant for decades, as [[environmental awareness]] has increased recently there has been a movement towards [[sustainable agriculture]] by some farmers, consumers, and policymakers. In recent years there has been a backlash against perceived [[externalities|external]] environmental effects of mainstream agriculture, particularly regarding water pollution<ref>The World Bank (1995) [http://www.worldbank.org/fandd/english/0996/articles/0100996.htm Overcoming Agricultural Water Pollution in the European Union]</ref>, resulting in the [[organic movement]]. One of the major forces behind this movement has been the [[European Union]], which first certified [[organic food]] in 1991 and began reform of its [[Common Agricultural Policy]] (CAP) in 2005 to phase out commodity-linked farm subsidies<ref>European Commission (2003) [http://ec.europa.eu/agriculture/capreform/index_en.htm CAP Reform ]</ref>, also known as [[Decouple#Economics|decoupling]]. The growth of [[organic farming]] has renewed research in alternative technologies such as [[integrated pest management]] and [[selective breeding]]. Recent mainstream technological developments include [[genetically modified food]].
As of late 2007, increased farming for use in [[biofuel]]s has pushed up the price of grain used to feed poultry and dairy cows and other cattle, causing higher prices of wheat (up 58%), soybean (up 32%), and maize (up 11%) over the year.<ref> ''New York Times'' (2007 September) [http://www.nytimes.com/2007/09/06/business/06tyson.html?n=Top/Reference/Times%20Topics/Subjects/W/Wheat At Tyson and Kraft, Grain Costs Limit Profit]</ref>
==Practices==
Agricultural practices lie on a spectrum dependent upon the intensity and technology of the methods. At the one end lies the [[subsistence agriculture|subsistence farmer]] who farms a small area with limited inputs and produces only enough [[food]] to meet the needs of his or her family. At the other end lies [[intensive agriculture]] which includes traditional labor intensive farming (e.g. South-East Asia rice paddies), and modern agriculture which includes [[industrial agriculture]], [[organic farming]] and [[sustainable farming]]. Industrial agriculture involves large fields and/or numbers of animals, high resource inputs (pesticides, fertilizers, etc.), and a high level of [[Mechanised agriculture|mechanization]]. These operations achieve [[economies of scale]] and require large amounts of capital in the form of land and machinery.
The twentieth century saw 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]], analysis of soil makeup and nutritional needs of farm animals.
Mechanization has increased farm efficiency and productivity in most regions of the world, due especially to the [[tractor]] and various "gins" (short for "engine") such as the [[cotton gin]], semi-automatic [[baler]]s and [[Threshing machine|thresher]]s and, above all, the [[Combine harvester|combine]] (see [[agricultural machinery]]). 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. By 1999, due to advances in agricultural technology, a single farmer could feed over 130 people.<ref>{{cite web |url=http://www.greatachievements.org/greatachievements/ga_7_2.html |title=http://www.greatachievements.org/greatachievements/ga_7_2.html |accessdate= |format= |work= }}</ref>
[[Image:Agriculture (Plowing) CNE-v1-p58-H.jpg|left|thumb|A [[tractor]] ploughing an [[alfalfa]] field]]
Other recent changes in agriculture include [[hydroponics]], [[plant breeding]], hybridization, [[genetic modification|gene manipulation]], better management of soil nutrients, and improved [[weed control]]. [[Genetically Modified Organism|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 on an accelerated schedule. Genetic engineering of plants has proven controversial, particularly in the case of [[Roundup|herbicide]]-resistant plants.
Genetic engineers at companies such as [[Monsanto]] are working to develop plants for [[irrigation]], [[drainage]], [[conservation ethic|conservation]] and sanitary engineering, particularly important in normally arid areas which rely upon constant irrigation, and on large scale farms.
The processing, packing and marketing of agricultural products are closely related activities also influenced by science. Methods of quick-freezing and dehydration have increased the markets for many farm products (see [[food preservation]] and [[meat packing industry]]).
Animals, including horses, mules, oxen, camels, llamas, alpacas, and dogs, are often used to help cultivate [[field (agriculture)|fields]], harvest [[crop (agriculture)|crops]], [[Wrangler (profession)|wrangle]] other animals, and transport farm products to buyers. [[Animal husbandry]] not only refers to the breeding and raising of animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis, but also to the breeding and care of species for work and companionship.
Airplanes, helicopters, trucks, tractors, and combines are used in Western (and, increasingly, Eastern) 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.
[[Image:KerbauJawa.jpg|thumb|left|Ploughing rice paddies with water buffalo, in [[Indonesia]].]]
In recent years, some aspects of intensive [[industrial agriculture]] have been the subject of increasing debate. 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 over the effect of intensive agriculture on the environment.
[[Image:Fields of gold.jpg|thumb|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 [[India]]n activist and scientist [[Vandana Shiva]] argues that these companies are guilty of [[biopiracy]].
[[Soil]] [[conservation ethic|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]].
==Etymology==
The word '''agriculture''' is the English adaptation of Latin ''agricultūra'', from ''ager'', "a field", and ''cultūra'', "[[cultivation]]" in the strict sense of "[[tillage]] of the soil". Thus, a literal reading of the word yields "tillage of a field / of fields".
==History==
{{main|History of agriculture}}
[[Image:ClaySumerianSickle.jpg|thumb|right|[[Sumer]]ian Harvester's sickle, 3000 BCE. Baked clay. [[Field Museum]].]]
===Ancient origins===
{{see|Neolithic Revolution}}
[[Image:Ancient egyptian farmer.gif|thumb|Ancient Egyptian farmer, copied from [[Archaeology|archaeologically]] preserved specimen by a modern artist guessing at original colors.<br><font size="-3" face="Verdana, sans-serif">Source: http://www.kingtutone.com</font>]]
Developed independently by geographically distant populations, systematic agriculture first appeared in [[Southwest Asia]] in the [[Fertile Crescent]], particularly in modern-day [[Iraq]] and [[Syria]]/[[Israel]]. Around [[9500 BCE]], proto-farmers began to select and cultivate food plants with desired characteristics. Though there is evidence of earlier sporadic use of wild cereals, it was not until after [[9500 BCE]] that the eight so-called [[Neolithic founder crops|founder crops]] of agriculture appear: first [[emmer wheat|emmer]] and [[einkorn wheat]], then hulled [[barley]], [[pea]]s, [[lentil]]s, [[bitter vetch]], [[chick pea]]s and [[flax]].
By [[7000 BCE]], small-scale agriculture reached [[Egypt]]. From at least [[7000 BCE]] the [[Indian subcontinent]] saw farming of [[wheat]] and [[barley]], as attested by archaeological excavation at [[Mehrgarh]] in [[Balochistan (region)|Balochistan]]. By [[6000 BCE]], mid-scale farming was entrenched on the banks of the [[Nile River|Nile]]. About this time, agriculture was developed independently in the Far East, with [[rice]], rather than wheat, as the primary crop. [[China|Chinese]] and [[Indonesia]]n farmers went on to domesticate [[mung bean|mung]], [[soy]], [[Azuki bean|azuki]] and [[taro]]. To complement these new sources of [[carbohydrates]], highly organized net [[fishing]] of rivers, lakes and ocean shores in these areas brought in great volumes of essential [[protein]]. Collectively, these new methods of farming and fishing inaugurated a human population boom dwarfing all previous expansions, and is one that continues today.
By [[5000 BCE]], the [[Sumer]]ians had developed core agricultural techniques including large scale intensive cultivation of land, [[mono-cropping]], organized [[irrigation]], and use of a specialized [[labour (economics)|labour]] force, particularly along the waterway now known as the [[Shatt al-Arab]], from its [[Persian Gulf]] delta to the confluence of the [[Tigris]] and [[Euphrates]]. Domestication of wild [[aurochs]] and [[mouflon]] into [[cattle]] and [[sheep]], respectively, ushered in the large-scale use of animals for food/fiber and as beasts of burden. The [[shepherd]] joined the farmer as an essential provider for [[sedentary]] and semi-[[nomadic]] societies.
[[Maize]], [[manioc]], and [[arrowroot]] were first domesticated in the Americas as far back as [[5200 BCE]]. [http://www.ucalgary.ca/news/feb2007/early-farming/] The [[potato]], [[tomato]], [[Capsicum|pepper]], [[Squash (fruit)|squash]], several varieties of [[legume|bean]], [[Canna (plant)|Canna]], [[tobacco]] and several other plants were also developed in the New World, as was extensive [[Terrace (agriculture)|terracing]] of steep hillsides in much of [[Andes|Andean]] [[South America]].
In later years, the [[Agriculture of ancient Greece|Greeks]] and [[Roman agriculture|Romans]] built on techniques pioneered by the Sumerians but made few fundamentally new advances. The Greeks and [[Macedonia (Greece)|Macedonia]]ns struggled with very poor soils, yet managed to become dominant societies for years. The Romans were noted for an emphasis on the cultivation of crops for [[trade]].
[[Image:al-jazari pump.png|thumb|A [[valve]]-operated [[reciprocating engine|reciprocating]] [[suction]] [[piston]] [[pump]] water-raising machine with a [[crankshaft]]-[[connecting rod]] mechanism invented by [[al-Jazari]].]]
===Agriculture in the Middle Ages===
{{main|Muslim Agricultural Revolution}}
During the Middle Ages, Muslim farmers in North Africa and the Near East developed and disseminated agricultural technologies including irrigation systems based on [[hydraulic]] and [[hydrostatic]] principles, the use of machines such as [[Water wheel|norias]], and the use of water raising machines, dams, and reservoirs. They also wrote location-specific farming manuals, and were instrumental in the wider adoption of crops including sugar cane, rice, citrus fruit, apricots, cotton, artichokes, aubergines, and saffron. Muslims also brought lemons, oranges, cotton, almonds, figs and sub-tropical crops such as bananas to Spain.
===Renaissance to present day===
{{see|British Agricultural Revolution|Green Revolution}}
[[Image:Agriculture (Plowing) CNE-v1-p58-H.jpg|left|thumb|A [[tractor]] ploughing an [[alfalfa]] field]]
The invention of a [[three field system]] of crop rotation during the [[Middle Ages]], and the importation of the Chinese-invented [[Moldboard#Mouldboard plough|moldboard]] plow, vastly improved agricultural efficiency.
After 1492, a global exchange of previously local crops and livestock breeds occurred. Key crops involved in this exchange included the [[tomato]], [[maize]], [[potato]], [[cocoa]] and [[tobacco]] going from the New World to the Old, and several varieties of wheat, [[spice]]s, [[coffee]], and [[sugar cane]] going from the Old World to the New. The most important animal exportations from the Old World to the New were those of the horse and dog (dogs were already present in the pre-Columbian Americas but not in the numbers and breeds suited to farm work). Although not usually food animals, the horse (including [[donkey]]s and [[ponies]]) and dog quickly filled essential production roles on western hemisphere farms.
By the early 1800s, agricultural techniques, implements, seed stocks and [[cultivar]]s had so improved that yield per land unit was many times that seen in the Middle Ages. With the rapid rise of [[mechanised agriculture|mechanization]] in the late 19th and 20th centuries, particularly in the form of the [[tractor]], farming tasks could be done with a speed and on a scale previously impossible. These advances have led to efficiencies enabling certain modern farms in the United States, [[Argentina]], [[Israel]], [[Germany]], and a few other nations to output volumes of high quality produce per land unit at what may be the practical limit.
In 2005, the [[Agriculture in China|agricultural output of China]] was the largest in the world, accounting for almost one-sixth world share followed by the EU, India and the USA, according to the [[International Monetary Fund]].
==Crops==
===World production of major crops in 2004===
Specific crops are cultivated in distinct [[growing region]]s throughout the world. In millions of metric tons, based on [[Food and Agriculture Organization|FAO]] estimates.
<center>
{| class="wikitable" align=left
! colspan=2|Top agricultural products, by crop types <br>(million metric tons) 2004 data
|-
| [[Cereal]]s || align="right" | 2,263
|-
| [[Vegetable]]s and [[melon]]s || align="right" | 866
|-
| [[Root]]s and [[Tuber]]s || align="right" | 715
|-
| [[Milk]] || align="right" | 619
|-
| [[Fruit]] || align="right" | 503
|-
| [[Meat]] || align="right" | 259
|-
| [[Vegetable oil|Oilcrops]] || align="right" | 133
|-
| [[Fish]] (2001 estimate) || align="right" | 130
|-
| [[Egg (food)|Eggs]] || align="right" | 63
|-
| [[Pulse (legume)|Pulses]] || align="right" | 60
|-
| [[Fiber crop|Vegetable Fiber]] || align="right" | 30
|-
|colspan=2|''Source: <br>[[Food and Agriculture Organization]] (FAO)''<ref name="FAO">{{cite web |url=http://faostat.fao.org/ |title=FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS (FAOSTAT) |accessdate= 2007-10-11 |format= |work= }}</ref>
|}
{| class="wikitable" align=middle
! colspan=2|Top agricultural products, by individual crops <br>(million metric tons) 2004 data
|-
| [[Sugar Cane]] || align="right" | 1,324
|-
| [[Maize]] || align="right" | 721
|-
| [[Wheat]] || align="right" | 627
|-
| [[Rice]] || align="right" | 605
|-
| [[Potato]]es || align="right" | 328
|-
| [[Sugar Beet]] || align="right" | 249
|-
| [[Soybean]] || align="right" | 204
|-
| [[Oil Palm]] Fruit || align="right" | 162
|-
| [[Barley]] || align="right" | 154
|-
| [[Tomato]] || align="right" | 120
|-
|colspan=2|''Source: <br>[[Food and Agriculture Organization]] (FAO)''<ref name="FAO" />
|}
<br clear="all">
</center>
=== Crop alteration ===
{{main|Plant breeding}}
[[Image:Ueberladewagen.jpg|thumb|[[Tractor]] and [[Chaser Bin]]]]
[[Image:Cropscientist.jpg|right|thumb|An agricultural scientist records corn growth]]
[[Image:Bird netting.jpg|thumb|Netting protecting wine grapes from birds]]
Domestication of plants has, over the centuries increased yield, improved disease resistance and drought tolerance, eased harvest and improved the taste and [[nutrition]]al value of crop plants. Careful selection and breeding have had enormous effects on the characteristics of crop plants. Plant breeders use [[greenhouse]]s (known as glasshouses or hothouses in some areas) and other techniques to get as many as three generations of plants per year towards the continued effort of improvement.
Plant selection and breeding in the 1920s and 1930s improved [[pasture]] (grasses and clover) in New Zealand. Extensive [[X-ray]] an [[ultraviolet]] induced mutagenesis efforts (i.e. primitive genetic engineering) during the 1950s produced the modern commercial varieties of grains such as wheat, corn and barley.<ref>{{cite journal | last = Stadler| first = L. J. | authorlink = Lewis Stadler | coauthors = G. F. Sprague | title = Genetic Effects of Ultra-Violet Radiation in Maize. I. Unfiltered Radiation | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 22 | issue = 10 | pages = 572-578 | publisher = US Department of Agriculture and Missouri Agricultural Experiment Station | date= 1936-10-15 | url = http://www.pnas.org/cgi/reprint/22/10/579.pdf | doi = | id = | accessdate = 2007-10-11 }}</ref><ref>{{cite book | last = Berg | first = Paul | coauthors =Maxine Singer | title = George Beadle: An Uncommon Farmer. The Emergence of Genetics in the 20th Century | publisher = Cold Springs Harbor Laboratory Press | date= 2003-08-15 | id = ISBN 0-87969-688-5 }}</ref>
For example, average yields of corn ([[maize]]) in the USA have increased from around 2.5 tons per hectare (t/ha) (40 bushels per acre) in 1900 to about 9.4 t/ha (150 bushels per acre) in 2001. 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 America]]n average wheat yields are around 2 t/ha, [[Africa]]n 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. Variation in yields are due mainly to variation in climate, genetics, and the level of intensive farming techniques (use of fertilizers, chemical [[pest control]], growth control to avoid lodging).<ref>{{cite journal | last = Ruttan | first = Vernon W. | title = Biotechnology and Agriculture: A Skeptical Perspective | journal = AgBioForum | volume = 2 | issue = 1 | pages = 54-60 | publisher = | date = Winter 1999 | url = http://www.mindfully.org/GE/Skeptical-Perspective-VW-Ruttan.htm | accessdate = 2007-10-11 }}</ref><ref>{{cite journal | last = Cassman | first = K. | authorlink = | coauthors = | title = Ecological intensification of cereal production systems: The Challenge of increasing crop yield potential and precision agriculture | journal = Proceedings of a National Academy of Sciences Colloquium, Irvine, California | volume = | issue = | pages = | publisher = University of Nebraska | date= 1998-12-05 | url = http://www.lsc.psu.edu/nas/Speakers/Cassman%20manuscript.html | doi = | id = | accessdate = 2007-10-11 }}</ref><ref>Conversion note: 1 bushel of wheat = 60 pounds (lb) ≈ 27.215 kg. 1 bushel of corn = 56 pounds ≈ 25.401 kg</ref>
After mechanical tomato-harvesters were developed in the early 1960s, agricultural scientists bred tomatoes that were more resistant to mechanical handling. These varieties have been criticized as being harder and having poor texture{{Fact|date=October 2007}}.
More recently, [[genetic engineering]] has begun to be employed in large parts of the world to speed up the selection and breeding process. One widely used modification is a [[Roundup|herbicide]] resistance gene that allows plants to tolerate exposure to [[glyphosate]], a non-systemic (i.e kills all plants) chemical used to control weeds in a crop such as oilseed rape. Normally, expensive [[systemic]] herbicides would have to be applied to kill the weeds without harming the crop. Relatively cheap and safe glyphosate may be applied to the modified crops, efficiently killing weeds without harming the resistant crop. Another modification causes the plant to produce a toxin to reduce damage from insects (c.f. [[Transgenic maize|Starlink]]). This, in contrast, requires fewer insecticides to be applied to the crop.
[[Aquaculture]], the farming of [[fish]], [[shrimp]], and [[algae]], is closely associated with agriculture.
[[Beekeeping|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]]
==Livestock==
{{main|Livestock}}
The farming practices of livestock vary dramatically world-wide and between different types of animals. Livestock are generally kept in an enclosure, are fed by human-provided food and are intentionally bred, but some livestock are not enclosed, or are fed by access to natural foods, or are allowed to breed freely, or all three. Approximately 68% of all agricultural land is used in the production of livestock as permanent pastures.<ref>FAO Database, 2003</ref>
==Environmental impact==
[[Image:Soil erosion1.jpg|thumb|upright|Severe [[soil erosion]] in a wheat field near [[Washington State University]], US (c.2005)]]Agriculture may often cause environmental problems because it changes natural environments and produces harmful by-products. Some of the negative effects are:
* Loss of [[biodiversity]]
* Surplus of [[nitrogen]] and [[phosphorus]] in [[river]]s and [[lake]]s
* Detrimental effects of [[herbicide]]s, [[fungicide]]s, [[insecticide]]s, and other [[biocide]]s
* Conversion of natural [[ecosystem]]s of all types into [[arable land]]
* Consolidation of diverse [[biomass]] into a few species
* [[Soil erosion]]
* Depletion of [[minerals]] in the [[soil]]
* [[Particulate matter]], including [[ammonia]] and [[ammonium]] off-gassing from animal waste contributing to [[air pollution]]
* [[Weed Science]] - [[feral]] plants and animals
* Odor from agricultural [[waste]]
* [[Soil salination]]
According to the United Nations, the livestock sector (primarily cows, chickens, and pigs) emerges as one of the top two or three most significant contributors to our most serious environmental problems, at every scale from local to global. Livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the planet.<ref>[http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf Food and Agricultural Organization of the U.N.] retrieved 27 jun 2007</ref>It is one of the largest sources of greenhouse gases—responsible for 18% of the world’s greenhouse gas emissions as measured in CO<sub>2</sub> equivalents. By comparison, all transportation emits 13.5% of the CO<sub>2</sub>. It produces 65% of human-related nitrous oxide (which has 296 times the global warming potential of CO<sub>2</sub>) and 37% of all human-induced methane (which is 23 times as warming as CO<sub>2</sub>). It also generates 64% of the ammonia, which contributes to acid rain and acidification of ecosystems.<ref>[http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.htm Livestock’s long shadow: Environmental issues and options]</ref>
==Genetic erosion in crop and livestock biodiversity==
{{TotallyDisputed-section}}
{{See also|Genetic erosion|Agricultural biodiversity}}
[[Genetic erosion]] in [[crop|crops]] and [[livestock]] biodiversity is propelled by several major factors such as variety replacement, land clearing, overexploitation of species, population pressure, environmental degradation, [[overgrazing]], policy and changing agricultural systems. {{Fact|date=November 2007}}
The main factor, however, is the replacement of local varieties of domestic plants and animals by high yielding or exotic varieties or species. A large number of varieties can also often be dramatically reduced when commercial varieties (including [[Genetically Modified Organism|GMO]]s) are introduced into traditional farming systems. Many researchers believe that the main problem related to agro-ecosystem management is the general tendency towards genetic and ecological uniformity imposed by the development of modern agriculture. {{Who|date=November 2007}}
In agriculture and [[animal husbandry]], the [[green revolution]] popularized the use of conventional [[hybrid (biology)|hybridization]] to increase yield many folds by creating "[[high-yielding varieties]]". Often the handful of breeds of plants and animals hybridized originated in developed countries and were further hybridized with local varieties in the rest of the developing world to create high yield strains resistant to local climate and diseases. Hybridization of local breeds to improve performance may lead to the loss of the local breed over time and consequently the loss of the genetic material that adapted that breed specifically to the local conditions. When viewed across the world as a whole, the consequent loss in genetic diversity and biodiversity could be placing the food supply in jeopardy, as a highly specialized breed may not contain sufficient genetic material to adapt to new diseases or environments even with an intensive breeding program.<ref>[http://www.farmedia.org/bulletins/bulletin28.html “Genetic Pollution: The Great Genetic Scandal”]; Devinder Sharma can be contacted at: 7 Triveni Apartments, A-6 Paschim Vihar, New Delhi-110 063, India. Email: dsharma@ndf.vsnl.net.in. CENTRE FOR ALTERNATIVE AGRICULTURAL MEDIA (CAAM)., [http://www.infochangeindia.org/features43.jsp]</ref>
A [[Genetically Modified Organism]] (GMO) is an [[organism]] whose [[gene]]tic material has been [[genetic engineering|altered]] using the [[genetic engineering]] techniques generally known as [[recombinant DNA technology]]. Genetic Engineering today has become another serious and alarming cause of genetic pollution because artificially created and genetically engineered plants and animals in laboratories, which could never have evolved in nature even with conventional hybridization, can live and breed on their own and what is even more alarming interbreed with naturally evolved wild varieties. Genetically Modified (GM) crops today have become a common source for genetic pollution, not only of wild varieties but also of other domesticated varieties derived from relatively natural hybridization.<ref>[http://query.nytimes.com/gst/fullpage.html?res=9C01E6DE143CF93AA35751C1A9679C8B63 THE YEAR IN IDEAS: A TO Z.; Genetic Pollution] By MICHAEL POLLAN, The New York Times, December 9, 2001</ref><ref>[http://www.nature.com/nbt/journal/v22/n1/full/nbt0104-29.html Dangerous Liaisons? When Cultivated Plants Mate with Their Wild Relatives] by Norman C. Ellstrand; The Johns Hopkins University Press, 2003; 268 pp. hardcover , $ 65; ISBN 0-8018-7405-X. Book Reviewed in: Hybrids abounding; Nature Biotechnology 22, 29 - 30 (2004) doi:10.1038/nbt0104-29; Reviewed by: Steven H Strauss & Stephen P DiFazio.</ref><ref>[http://www.fao.org/DOCREP/003/X3910E/X3910E00.htm “Genetic pollution: Uncontrolled spread of genetic information (frequently referring to transgenes) into the genomes of organisms in which such genes are not present in nature.”] Zaid, A. et al. 1999. Glossary of biotechnology and genetic engineering. FAO Research and Technology Paper No. 7. ISBN 92-5-104369-8</ref><ref>[http://plpa.cfans.umn.edu/~neviny/agri1501/definitions.html “Genetic pollution: Uncontrolled escape of genetic information (frequently referring to products of genetic engineering) into the genomes of organisms in the environment where those genes never existed before.”] Searchable Biotechnology Dictionary. University of Minnesota. [http://iufro-archive.boku.ac.at/silvavoc/glossary/6_0en.html]</ref><ref>[http://www.scienzagiovane.unibo.it/English/pollution/2-facets.html “Genetic pollution: Living organisms can also be defined as pollutants, when a non-indigenous species (plant or animal) enters a habitat and modifies the existing equilibrium among the organisms of the affected ecosystem (sea, lake, river).] Non-indigenous, including transgenic species (GMOs), may bring about a particular version of pollution in the vegetal kingdom: so-called genetic pollution. This term refers to the uncontrolled diffusion of genes (or transgenes) into genomes of plants of the same type or even unrelated species where such genes are not present in nature. For example, a grass modified to resist herbicides could pollinate conventional grass many miles away, creating weeds immune to the most widely used weed-killer, with obvious consequences for crops. Genetic pollution is at the basis of the debate on the use of GMOs in agriculture.” The many facets of pollution; Bologna University web site for Science Communication. The Webweavers: Last modified Tue, 20 Jul 2005</ref>
==Policy==
{{main|Agricultural 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.<ref>[http://www.csmonitor.com/2007/0724/p01s01-wogi.html Rising food prices curb aid to global poor]</ref><ref>[http://www.finfacts.com/irelandbusinessnews/publish/article_1011078.shtml Record rise in wheat price prompts UN official to warn that surge in food prices may trigger social unrest in developing countries]</ref>
*[[Food quality]]: Ensuring that the food supply is of a consistent and known quality.
* Poverty Reduction
* Conservation
* Environmental impact
* Economic stability
==Agriculture and petroleum==
{{further|[[Peak oil#Agriculture and population limits|Peak oil, agriculture and population]]; [[Biofuel#Rising food prices/the "food vs. fuel" debate|Effect of biofuels on food prices]]}}
Since the 1940s, agriculture has dramatically increased its productivity, due largely to the use of petrochemical derived [[pesticide]]s, fertilizers, and increased [[mechanization]]. This has allowed [[world population]] to grow more than double over the last 50 years. Every energy unit delivered in food grown using modern techniques requires over ten energy units to produce and deliver. The vast majority of this energy input comes from fossil fuel sources. Because of modern agriculture's current heavy reliance on petrochemicals and mechanization, there are warnings that the ever decreasing supply of oil (the dramatic nature of which is known as [[peak oil]]<ref name=deffeyes012007>
{{cite web
|url=http://www.princeton.edu/hubbert/current-events.html
|title=Current Events - Join us as we watch the crisis unfolding
|date=2007-01-19
|publisher=[[Princeton University: Beyond Oil]]
|author=Kenneth S. Deffeyes
|language=English
}}</ref><ref name=mcgreal102007>{{cite web
|url=http://raisethehammer.org/article/643/
|title=Yes, We're in Peak Oil Today
|publisher=Raise the Hammer
|date=2007-10-22
|author=Ryan McGreal
|language=English
}}</ref><ref name=ewg1007>
{{cite web
|url=http://www.energywatchgroup.org/fileadmin/global/pdf/EWG_Oilreport_10-2007.pdf
|title=Crude Oil: The Supply Outlook
|publisher=Energy Watch Group
|date=2007-10
|author=Dr. Werner Zittel, Jorg Schindler
|language=English
}}</ref><ref name=cohen102007>{{cite web
|url=http://www.aspo-usa.com/index.php?option=com_content&task=view&id=243&Itemid=91
|title=The Perfect Storm
|author=Dave Cohen
|publisher=ASPO-USA
|date=October 31, 2007
|language=English
}}</ref><ref name=koppelaar092006>
{{cite web
|url=http://peakoil.nl/wp-content/uploads/2006/09/asponl_2005_report.pdf
|format=PDF
|title=World Production and Peaking Outlook
|publisher=[[Peak Oil Netherlands]]
|author=Rembrandt H.E.M. Koppelaar
|date=2006-09
|language=English
}}</ref>) will inflict major damage on the modern industrial agriculture system, and could cause large food shortages.<ref>(a list of over 20 published articles and books supporting this thesis can be found [http://dieoff.org/ here] in the section: "Food, Land, Water, and Population")</ref>
Oil shortages are one of several factors making [[organic agriculture]] and other [[sustainable farming]] methods necessary. This conversion is now occurring{{Fact|date=December 2007}}, but the reconditioning of soil to restore nutrients lost during the use of [[monoculture]] agriculture techniques made possible by petroleum-based technology will take time. Some farmers using modern organic-farming methods have reported yields as high as those available from conventional farming (but without the use of fossil-fuel-intensive artificial fertilizers or pesticides).<ref>http://www.biotech-info.net/Alex_Avery.html</ref><ref>http://extension.agron.iastate.edu/organicag/researchreports/nk01ltar.pdf</ref><ref>http://www.cnr.berkeley.edu/~christos/articles/cv_organic_farming.html</ref><ref>http://www.terradaily.com/news/farm-05c.html</ref>
Farmers have also begun raising crops such as corn for non-food use in an effort to help [[mitigation of peak oil|mitigate peak oil]]. This has led to a 60% rise in wheat prices recently, and has been indicated as a possible precursor to "serious social unrest in developing countries."<ref>[http://www.finfacts.com/irelandbusinessnews/publish/article_1011078.shtml Record rise in wheat price prompts UN official to warn that surge in food prices may trigger social unrest in developing countries]</ref> Such situations would be exacerbated in the event of future rises in food and fuel costs, factors which have already impacted the ability of charitable donors to send food aid to starving populations.<ref>[http://www.csmonitor.com/2007/0724/p01s01-wogi.html Rising food prices curb aid to global poor]</ref>
==Agriculture safety and health==
[[Image:Crops Kansas AST 20010624.jpg|thumb|right|Satellite image of circular crop fields characteristic of [[center pivot irrigation]] in [[Haskell County, Kansas]] in late June 2001. Healthy, growing crops are green. [[maize|Corn]] is growing leafy stalks, but [[Sorghum]], which resembles corn, grows more slowly and is much smaller and therefore paler. [[Wheat]] is a brilliant gold as harvest occurs in June. Brown fields have been recently harvested and plowed under or lie [[fallow]] for the year.]]
'''United States'''
Agriculture ranks among the most hazardous industries. <ref>{{cite web|url=http://www.cdc.gov/niosh/topics/agriculture/|title=NIOSH- Agriculture|accessdate=2007-10-10|publisher=United States National Institute for Occupational Safety and Health}}</ref> Farmers are at high risk for fatal and nonfatal injuries, work-related lung diseases, noise-induced hearing loss, skin diseases, and certain cancers associated with chemical use and prolonged sun exposure. Farming is one of the few industries in which the families (who often share the work and live on the premises) are also at risk for injuries, illness, and death.
* In an average year, 516 workers die doing farm work in the U.S. (1992-2005). Of these deaths, 101 are caused by tractor overturns.
* Every day, about 243 agricultural workers suffer lost-work-time injuries, and about 5% of these result in permanent impairment.<ref name=NIOSH_AgInj>{{cite web|url=http://www.cdc.gov/niosh/topics/aginjury//|title=NIOSH- Agriculture Injury|accessdate=2007-10-10|publisher=United States National Institute for Occupational Safety and Health}}</ref>
'''Young Workers'''
Agriculture is the most dangerous industry for young workers, accounting for 42% of all work-related fatalities of young workers in the U.S. between 1992 and 2000. Unlike other industries, half the young victims in agriculture were under age 15. <ref> NIOSH [2003]. Unpublished analyses of the 1992–2000 Census of Fatal Occupational Injuries Special Research Files provided to NIOSH by the Bureau of Labor Statistics (includes more detailed data than the research file, but excludes data from New York City). Morgantown, WV: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Safety Research, Surveillance and Field Investigations Branch, Special Studies Section. Unpublished database. </ref>
For young agricultural workers aged 15–17, the risk of fatal injury is four times the risk for young workers in other workplaces <ref>BLS [2000]. Report on the youth labor force. Washington, DC: U.S. Department of Labor, Bureau of Labor Statistics, pp. 58–67. </ref> Agricultural work exposes young workers to safety hazards such as machinery, confined spaces, work at elevations, and work around livestock.
* An estimated 1.26 million children and adolescents under 20 years of age resided on farms in 2004, with about 699,000 of these youth performing work on the farms. In addition to the youth who live on farms, an additional 337,000 children and adolescents were hired to work on U.S. farms in 2004.
* On average, 103 children are killed annually on farms (1990-1996). Approximately 40 percent of these deaths were work-related.
* In 2004, an estimated 27,600 children and adolescents were injured on farms; 8,100 of these injuries were due to farm work.<ref name=NIOSH_AgInj/>
==See also==
: ''Main lists: [[List of basic agriculture topics]] and [[List of agriculture topics]]''
{{Horticulture and Gardening}}
* [[Aeroponics]]
* [[Agricultural Engineering]]
* [[Agrocenter]]
* [[Apiculture]]
* [[Climate change and agriculture]]
* [[Dismal Science]] - highlighting the imperative for continuous advancement in agricultural science
* [[Geoponic]]
* [[Green Revolution]]
* [[Horticulture]]
* [[Hydroponic]]
* [[Industrial agriculture]]
* [[Integrated Pest Management]] ([[Integrated Pest Management|IPM]])
* [[List of countries by GDP sector composition|List of countries by agricultural output]]
* [[List of domesticated animals]]
* [[List of subsistence techniques]]
* [[List of sustainable agriculture topics]]
* [[Organic farming]]
* [[Permaculture]]
* [[Timeline of agriculture and food technology]].
==References==
{{reflist}}
{{Refbegin}}
*Artz, F. B, (1980), ‘The Mind of the Middle Ages’; Third edition revised; The University of Chicago Press,
*Bolens, L. (1997), `Agriculture’ in Encyclopedia of the history of Science, technology, and Medicine in Non Western Cultures, Editor: Helaine Selin; Kluwer Academic Publishers. Dordrecht/Boston/London, pp 20-2
*Collinson, M. (editor): ''A History of Farming Systems Research''. CABI Publishing, 2000. ISBN 0-85199-405-9
*Crosby, Alfred W.: ''The Columbian Exchange : Biological and Cultural Consequences of 1492''. Praeger Publishers, 2003 (30th Anniversary Edition). ISBN 0-275-98073-1
*Davis, Donald R., and Hugh D. Riordan (2004) Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999. Journal of the American College of Nutrition, Vol. 23, No. 6, 669-682.
*Friedland, William H. and Amy Barton (1975) Destalking the Wily Tomato: A Case Study of Social Consequences in California Agricultural Research. Univ. California at Sta. Cruz, Research Monograph 15.
*Saltini A.''Storia delle scienze agrarie'', 4 vols, Bologna 1984-89, ISBN 88-206-2412-5, ISBN 88-206-2413-3, ISBN 88-206-2414-1, ISBN 88-206-2414-X
*Watson, A.M (1974), ‘The Arab agricultural revolution and its diffusion’, in The Journal of Economic History, 34,
*Watson, A.M (1983), ‘ Agricultural Innovation in the Early Islamic World’, Cambridge University Press
*Wells, Spencer: ''The Journey of Man : A Genetic Odyssey''. Princeton University Press, 2003. ISBN 0-691-11532-X
*Wickens, G.M.(1976), ‘What the West borrowed from the Middle east’, in Introduction to Islamic Civilization, edited by R.M. Savory, Cambridge University Press, Cambridge
{{Refend}}
[[Image:Coffee Plantation.jpg|thumb|600px|center|Coffee Plantation in São João do Manhuaçu City - [[Minas Gerais]] State - [[Brazil]].]]
==External links==
* [http://www.ukagriculture.com/ UKAgriculture.com] - Advance the education of the public in all aspects of agriculture, the countryside and the rural economy
* [http://www.cdc.gov/niosh/topics/agriculture National Institute for Occupational Safety and Health - Agriculture Page]
* [http://odi.org.uk/agriculture Research on the role of Agriculture in Poverty Reduction] from the [[Overseas Development Institute]]
{{wikibooks|Genes, Technology and Policy}}
{{wikiversity3|School:Agriculture|Agriculture|The School of Agriculture}}
{{commonscat|Agriculture}}
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