La agricultura (abarca cultivar, ranching, y tender de huertas y de viñedos) es la producción del alimento, de la alimentación, de la fibra, del combustible y de otras mercancías por levantar sistemático de plantas y de animales. Agri es del ager latino, significando “un campo”, y la cultura es del cultura latino, significando la “cultivación” en el sentido terminante de la labranza del suelo. Una lectura literal de la palabra inglesa rinde: labranza del suelo de un campo. En uso moderno, la agricultura de la palabra cubre todas las actividades esenciales para la producción del alimento/de la alimentación/de la fibra, incluyendo todas las técnicas para levantar y “procesar” el ganado. La agricultura está también brevemente para el estudio de la práctica de agricultura-más conocido formalmente como agronomía. La historia de la agricultura es un elemento importante de la historia humana, pues el progreso agrícola ha sido un factor crucial en cambio socioeconómico mundial, incluyendo el abundancia-edificio y las especializaciones militaristic consideradas raramente en el cazador-gatherer cultura-cuando los granjeros hicieron capaces de producir el alimento más allá de las necesidades de sus propias familias, otros en la tribu/la nación/el imperio fueron liberadas para dedicarse a las ambiciones y a las empresas con excepción de la adquisición del alimento. los 42% de los trabajadores del mundo se emplean en la agricultura, haciéndote en gran medida la ocupación más común. Sin embargo, la producción agrícola explica menos el de 5% del producto grueso del mundo (un agregado de todos los productos internos brutos). [1] Descripción El término “que cultiva” cubre la amplia gama de prácticas agrícolas. En un final del espectro está el granjero de la subsistencia, que cultiva un área pequeña con las entradas limitadas del recurso, y produce solamente bastante alimento para resolver las necesidades de su familia. En el otro extremo está la agricultura intensiva comercial, incluyendo agricultura industrial. El tal cultivar implica campos y/o números grandes de animales, de las entradas grandes del recurso (pesticidas, fertilizantes, etc.), y de un de alto nivel de la mecanización. Estas operaciones procuran generalmente maximizar renta financiera del grano, del producto, o del ganado. La agricultura moderna extiende bien más allá de la producción tradicional del alimento para los piensos del ser humano y. Otras mercancías de la producción agrícola incluyen la madera, fertilizantes, animal ocultan, forran con cuero, los productos químicos industriales (almidón, azúcar, etanol, alcoholes y plásticos), las fibras (algodón, lanas, cáñamo, y lino), los combustibles (metano de la biomasa, biodiesel), las flores del corte, las plantas ornamentales y del cuarto de niños, los pescados tropicales y los pájaros para el comercio del animal doméstico, y las drogas legales e ilegales (biopharmaceuticals, tabaco, marijuana, opio, cocaína). El vigésimo siglo consideró cambios masivos en práctica agrícola, particularmente en química agrícola y en la mecanización. La química agrícola incluye el uso del fertilizante químico, de los insecticidas químicos (véase el control de parásito), y de los fungicidas químicos, del maquillaje del suelo, del análisis de productos agrícolas, y de necesidades alimenticias de los animales del campo. Hasta e incluyendo los años 70, la salida superficial del fertilizante y los pesticidas eran un crecimiento y un problema incontrolado. Mirando fijamente áspero en el an o 80, muchas naciones occidentales, pincharon por docenas de grupos ambientales de la acción, comenzaron a poner controles en ejecución eficaces en la contaminación agricultura-relacionada, y la revolución verde separó muchas de las ventajas de la química agrícola a las granjas a través del mundo, sin la contaminación extrema que las acompañó originalmente. La mecanización también enormemente ha aumentado eficacia y productividad de la granja en la mayoría de las regiones del mundo, especialmente bajo la forma de tractor y varias ginebras (cortos para el “motor”) como la ginebra de algodón, las prensas semiautomáticas y las trilladoras (véase la maquinaria agrícola). Otros cambios recientes en agricultura incluyen hydroponics, la crianza de planta, el hibridación, la manipulación del gene, una gerencia mejor de los alimentos del suelo, y control mejorado de la mala hierba. La ingeniería genética ha rendido las cosechas que tienen capacidades más allá de los de plantas naturales, tales como producciones y resistencia más altas de la enfermedad. Las semillas modificadas germinan más rápidamente, y se pueden crecer así en un área de crecimiento extendida. La ingeniería genética de plantas ha probado polémico, particularmente en el caso de las plantas herbicida-resistentes. Los ingenieros pueden desarrollar las plantas para la irrigación, el drenaje, la conservación y la ingeniería sanitaria, particularmente importantes en las áreas normalmente áridas que confían en la irrigación constante, y en granjas de la escala grande. El embalaje, el proceso, y la comercialización de productos agrícolas son actividades de cerca relacionadas también influenciadas por la ciencia. Los métodos de quick-freezing y la deshidratación han aumentado los mercados para los productos de la granja (véase la preservación de alimento y la industria del embalaje de la carne). Los animales, incluyendo caballos, las mulas, bueyes, camellos, llamas, alpacas, y perros, son de uso frecuente cultivar campos, cosechar cosechas y transportar productos de la granja a los mercados. La agricultura animal no sólo refiere a los animales de crianza y que levantan para la carne o cosechar los productos animales (como la leche, los huevos, o las lanas) sobre una base continua, solamente la crianza y el cuidado de la especie para el trabajo y el compañerismo. Los aeroplanos, los helicópteros, los carros, los tractores, y las cosechadoras se utilizan en la agricultura occidental para sembrar, rociando 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.

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