A agricultura (abrange cultivar, ranching, e tender dos pomares e dos vinhedos) é a produção do alimento, da alimentação, da fibra, do combustível e dos outros bens pelo levantamento sistemático das plantas e dos animais. Agri é do ager Latin, significando “um campo”, e a cultura é do cultura Latin, significando o “cultivation” no sentido estrito do tillage do solo. Uma leitura literal da palavra inglesa rende: tillage do solo de um campo. No uso moderno, a agricultura da palavra cobre todas as atividades essenciais à produção do alimento/alimentação/fibra, including todas as técnicas para levantar e “processar” animais domésticos. A agricultura é também brevemente para o estudo da prática do agricultura-mais sabido formalmente como a ciência agricultural. A história da agricultura é um elemento principal da história humana, porque o progresso agricultural foi um fator crucial na mudança socio-economic worldwide, including o riqueza-edifício e os specializations militaristic vistos raramente no caçador-gatherer cultura-quando os fazendeiros se tornaram capazes de produzir o alimento além das necessidades de suas próprias famílias, outro no tribe/nação/império foram livrados para se devotar às ambições e às empresas à excepção da aquisição do alimento. 42% dos laborers do mundo são empregados na agricultura, fazendo lhe por muito a ocupação a mais comum. Entretanto, a produção agricultural esclarece menos de 5% do produto bruto do mundo (um agregado de todos os produtos domésticos brutos). [1] A vista geral o termo “que cultiva” cobre o spectrum largo de práticas agriculturais. Em um fim do spectrum está o fazendeiro do subsistence, que cultiva uma área pequena com entradas limitadas do recurso, e produz somente bastante alimento para encontrar-se com as necessidades de his/sua família. É no extremo oposto a agricultura intensive comercial, including a agricultura industrial. Tal cultivar envolve campos e/ou números grandes dos animais, das entradas grandes do recurso (pesticides, fertilizantes, etc.), e de uma elevação - em nível do mechanization. Estas operações tentam geralmente maximize a renda financeira da grão, do produto, ou dos animais domésticos. A agricultura moderna estende bem além da produção tradicional do alimento para as alimentações do ser humano e as animais. Outros bens da produção agricultural incluem a madeira, fertilizantes, animal escondem, revestem, produtos químicos industriais (starch, açúcar, ethanol, álcoois e plásticos), fibras (algodão, lãs, hemp, e flax), combustíveis (methane do biomass, o biodiesel), flores do corte, plantas ornamental e do berçário, peixes tropicais e pássaros para o comércio do animal de estimação, e drogas legais e ilegais (biopharmaceuticals, tabaco, marijuana, opium, cocaína). O vigésimo século viu mudanças maciças na prática agricultural, particularmente no chemistry agricultural e no mechanization. O chemistry agricultural inclui a aplicação do fertilizante químico, de insecticides químicos (ver o controle de pest), e de fungicides químicos, de composição do solo, de análise de produtos agriculturais, e de necessidades nutritivas de animais de fazenda. Até e incluindo os 1970s, o runoff de superfície do fertilizante e os pesticides eram um crescimento e um problema descontrolado. Olhando fixamente aproximadamente em 1980, muitas nações ocidentais, prodded por dúzias de grupos ambientais da ação, começaram a executar controles eficazes em poluição agricultura-relacionada, e a volta verde espalhou muitos dos benefícios do chemistry agricultural às fazendas durante todo o mundo, sem a poluição extrema que as acompanhou originalmente. O Mechanization também aumentou enormemente a eficiência e a produtividade da fazenda em a maioria de regiões do mundo, especialmente no formulário do trator e dos vários gins (curtos para o “motor”) como o gin de algodão, as prensas semiautomáticas e os threshers (ver a maquinaria agricultural). Outras mudanças recentes na agricultura incluem o hydroponics, produzir de planta, o hybridization, a manipulação do gene, gerência melhor de nutrientes do solo, e o controle melhorado da erva daninha. A engenharia Genetic rendeu as colheitas que têm potencialidades além daquelas de plantas naturais, tais como uns rendimentos e uma resistência mais elevados da doença. As sementes modificadas germinate mais rapidamente, e assim podem ser crescidas em uma área de crescimento prolongada. A engenharia Genetic das plantas provou controverso, particularmente no exemplo de plantas herbicide-resistentes. Os coordenadores podem desenvolver plantas para a irrigação, a drenagem, o conservation e a engenharia sanitária, as particularmente importantes nas áreas normalmente arid que confiam na irrigação constante, e em fazendas da escala grande. A embalagem, processar, e o marketing de produtos agriculturais são atividades pròxima relacionadas influenciadas também pela ciência. Os métodos de quick-freezing e a desidratação aumentaram os mercados para produtos da fazenda (ver a preservação de alimento e a indústria da embalagem da carne). Os animais, including cavalos, as mulas, bois, camelos, lamas, alpacas, e cães, são usados frequentemente cultivar campos, colher colheitas e transportar produtos da fazenda aos mercados. O husbandry animal consulta não somente aos animais produzindo e de levantamento para a carne ou aos produtos animais da colheita (como o leite, os ovos, ou as lãs) em uma base contínua, mas produzir e o cuidado da espécie para o trabalho e o companionship. Os aviões, os helicópteros, os caminhões, os tratores, e as ligas são usados na agricultura ocidental semeando, pulverizando o operatio ns 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 barleyThe 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. Ancient origins Developed independently by geographically distant populations, systematic agriculture first appeared in Southwest Asia in the Fertile Crescent, particularly in modern-day southern Iraq and Syria. Around 9500 BC, 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 BC that the eight so-called founder crops of agriculture appear: first emmer and einkorn wheat, then hulled barley, peas, lentils, bitter vetch, chick peas and flax. By 7000 BC, small-scale agriculture reached Egypt. From 7000 BC the Indian subcontinent saw farming of wheat and barley, attested by archaeological excavation at Mehrgarh in Balochistan. By 6000 BC, mid-scale farming was entrenched on the banks of the Nile River. About this time, agriculture was developed independently in the Far East, with rice, rather than wheat, as the primary crop. Chinese and Indonesian farmers went on to domesticate mung, soy, 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. By 5000 BC, the Sumerians had developed core agricultural techniques including large scale intensive cultivation of land, mono-cropping, organized irrigation, and use of a specialized 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 5300 BC.[1] The potato, tomato, pepper, squash, several varieties of bean, Canna, tobacco and several other plants were also developed in the New World, as was extensive terracing of steep hillsides in much of Andean South America. In later years, the Greeks and Romans built on techniques pioneered by the Sumerians but made few fundamentally new advances. The Greeks and Macedonians 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. Sumerian Harvester's sickle, 3000 BCE. Baked clay. Field Museum. [edit] Agriculture in the Middle Ages 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 norias, and the use of water raising machines, dams, and reservoirs. Muslims 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. [edit] Renaissance to present day A tractor ploughing an alfalfa fieldThe invention of a three field system of crop rotation during the Middle Ages, and the importation of the Chinese-invented 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, tobacco, and coffee going from the New World to the Old, and, primarily, several varieties of wheat and spice going from the Old World to the New. The most important animal exportation was that of the horse from the Old World to the New. Although not usually a food animal, the horse (including donkeys and ponies) quickly filled essential production roles on the farm. By the early 1800s, agricultural techniques, implements, seed stocks and cultivars had so improved that yield per land unit was many times that seen in the Middle Ages. With the rapid rise of 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. Agricultural output in 2005In 2005, China was the largest producer of agricultural output with almost one-sixth world share followed by the EU, India and the USA, reports the International Monetary Fund.