Agricultural Revolution Gradual transformation of the traditional agricultural system that began in Britain in the 18th century. Aspects of this complex transformation, which was not completed until the 19th cen¬ tury, included the reallocation of land ownership to make farms more compact and an increased investment in technical improvements, such as new machinery, better drainage, scientific methods of breeding, and experimentation with new crops and systems of crop rotation. The agri¬ cultural revolution was an essential prelude to the Industrial Revolution.
agriculture Science or art of cultivating the soil, growing and harvest¬ ing crops, and raising livestock. Agriculture probably first developed in South Asia and Egypt, then spread to Europe, Africa, the rest of Asia, the islands of the central and South Pacific, and finally to North and South America. Agriculture in the Middle East is believed to date from 9000- 7000 bc. Early cultivated crops include wild barley (Middle East), domes¬ ticated beans and water chestnuts (Thailand), and pumpkins (the Americas). Domestication of animals occurred during roughly the same period. Slash-and-burn land-clearing methods and crop rotation were early agricultural techniques. Steady improvements in tools and methods over the centuries increased agricultural output, as did mechanization, selective breeding and hybridization, and, in the 20th century, the use of herbicides and insecticides. More of the world’s aggregate manpower is devoted to agriculture than to all other occupations combined.
agrimony Va-gro-.mo-neX Any plant of the genus Agrimonia, of the rose family, especially A. eupatoria. This species is a herbaceous, hardy perennial native to Europe but widespread in other northern temperate regions, where it grows in hedge banks and the borders of fields. Its leaves yield a yellow dye. The leaflets are oval with toothed margins; the small, stalkless yellow flowers are borne in a long terminal spike. The fruit is a tiny burr. A. gryposepala, a similar species, is widespread in the U.S.
Agrippa b-'grip-oX, Marcus Vipsanius (b. 63 bc? —d. March, 12 bc, Campania) Powerful deputy of Augustus. He helped Octavian (later Augustus) take power after Julius Caesar’s murder (44 bc), defeating Sextus Pompeius in 36 and Mark Ant¬ ony at the Battle of Actium in 31. He went on to quell rebellions, found colonies, administer parts of the empire, and give to Rome funds for public works and buildings. In 23 Augustus seemed to make him heir, and Agrippa married Augustus’s daughter, Julia. His administrative and military skills were particularly directed to the eastern empire, where in 15 he met with and made an ally of Herod of Judaea. Agrippa’s writ¬ ings (now lost) influenced Strabo and Puny the Elder. His daughter Agrippina the Elder (14? bc-ad 33) was the wife of Germanicus Caesar, mother of Caliguia and Agrippina the Younger, and grandmother of Nero.
Agrippina X.ag-ri-'pI-noV the Younger (b. ad 15—d. 59) Mother of Nero and a major influence in the early years of his reign. Daughter of Agrippina the Elder (c. 14 bc-ad 33) and sister of Caugula, she was exiled (39—41) for conspiring against Caligula. Her first husband, Gnaeus Domi- tius Ahenobarbus, was Nero’s father. Accused of poisoning her second husband (49), she married Claudius, her uncle, and had him adopt Nero
Agouti (Dasyprocta).
WARREN GARST/TOM STACK & ASSOCIATES
Marcus Vipsanius Agrippa, marble portrait bust, early 1 st century bc; in the Louvre, Paris.
CLICHE MUSEES NATIONAUX, PARIS
© 2006 Encyclopaedia Britannica, Inc.
30 I agrochemical ► Ahmad Sirhindi
as his heir instead of his own son. She poisoned her son’s rivals, and when Claudius died in 54 she was suspected of having poisoned him. She became regent when Nero took the throne at age 16, but she gradually lost power. He tried to murder her when she opposed one of his affairs, and he finally had her put to death at her country house.
agrochemical Any chemical used in agriculture, including chemical fertilizers, herbicides, and INSECTICIDES. Most are mixtures of two or more chemicals; active ingredients provide the desired effects, and inert ingre¬ dients stabilize or preserve the active ingredients or aid in application. Together with other technological advances, including tractors, mechani¬ cal harvesters, and irrigation pumps, agrochemicals have increased the per-acre productivity of regions such as the Great Plains by 200-300% since the 1930s. Their long-term effects on the environment and the sta¬ bility of agricultural systems that use them are hotly debated.
agronomy Branch of agriculture that deals with field crop production and soil management. Agronomists generally work with crops that are grown on a large scale (e.g., small grains) and that require relatively little management. Agronomic experiments focus on a variety of factors relat¬ ing to crop plants, including yield, diseases, cultivation, and sensitivity to factors such as climate and soil.
Aguan \a-'gwan\ River River, northern Honduras. It rises in the cen¬ tral highlands west of Yoro, descends northeast to the coastal lowlands for a distance of 150 mi (240 km), and empties into the Caribbean Sea near Santa Rosa de Aguan. The lands along the river are used primarily for agriculture but are susceptible to floods and hurricanes.
Aguascalientes \,a-gwas-kal-'yen-tas\ State (pop., 2000: 944,285), central Mexico. With an area of 2,112 sq mi (5,471 sq km), it is one of the country’s smallest states. It occupies part of the central plateau. It was explored by Spaniards in the 16th century and became a colonial mining centre. During the revolution of 1910-20 it was the scene of bitter fight¬ ing. Today it is a fertile agricultural area and is noted for its mineral pro¬ duction. Its capital is the city of Aguascalientes.
Aguascalientes City (pop., 2000: 594,056), capital of Aguascalientes state, Mexico. Located on the Aguascalientes River, it was founded as a mining settlement in 1575 and became the state capital in the 1850s. It is sometimes called La Ciudad Perforada (“The Perforated City”) because of an underground labyrinth of tunnels built by an unknown pre-Columbian people. It is an agricultural centre, with several industries. Several notable churches possess outstanding examples of colonial religious art.
March 23, 1869, near Cavite,
Aguinaldo \,a-ge-'nal-do\, Emilio (b Luzon, Phil.—d. Feb. 6, 1964,
Manila) Philippine independence leader. He was born of Chinese and Tagalog parentage and was educated at the University of Santo Tomas,
Manila. He became a leader of the Katipunan, a revolutionary society that fought the Spanish. Philippine independence was declared in 1898, and Aguinaldo became president, but within months Spain signed a treaty ceding the islands to the U.S. Agui¬ naldo fought U.S. forces until he was captured in 1901. After taking an oath of allegiance to the U.S., he was induced to retire from public life. He collaborated with the Japanese dur¬ ing World War II. After the war he was briefly imprisoned; released by presidential amnesty, he was vindicated by his appointment to the Council of State in 1950. In his later years he promoted nationalism, democracy, and improvement of relations between the U.S. and the Philippines.
Emilio Aguinaldo.
BROWN BROTHERS
Agulhas \3-'g3l-9s\, Cape Cape, southernmost point of the African continent. Its name, Portuguese for “needles,” refers to the rocks and reefs that have wrecked many ships. The cape’s meridian of 20°E is the offi¬ cial boundary between the Indian and Atlantic oceans.
Agusan River \3-'gu-,san\ River, Mindanao, Philippines. Rising in the southeast and flowing north 240 mi (390 km) to enter Butuan Bay of the Bohol Sea, it forms a fertile valley 40-50 mi (65-80 km) wide between the Central Mindanao Highlands and the Pacific Cordillera. It is navigable
for 160 mi (260 km). Despite early Spanish contacts in the 17th century, most of the valley has remained sparsely settled by native peoples.