Background (Encyclopedia of Global Resources)
The beginnings of agriculture predate the written history of humankind. No one knows when the first crop was cultivated, but at some time in the distant past humans discovered that seeds from certain wild grasses could be collected and planted in land that could be controlled, the end product of which could later be gathered for food. Most authorities believe this occurred at about the same time in both the Old World and New World, some eight thousand to ten thousand years ago. The earliest attempts at growing crops were primarily to supplement the food supply provided by hunting and gathering. However, as the ability to produce crops increased, people began to domesticate animals, and their reliance on hunting and gathering decreased, allowing the development of permanent human settlements.
As far back as six thousand years ago, agriculture was firmly established in Asia, India, Mesopotamia, Egypt, Mexico, Central America, and South America. The earliest agricultural centers were located near large rivers that helped maintain soil fertility by the deposition of new topsoil with each annual flooding cycle. As agriculture moved into regions that lacked the annual flooding of the large rivers, people began to utilize a technique known as slash-and-burn agriculture. In this type of agriculture, a farmer clears a field, burns the trees and brush, and farms the field. After a few years, soil nutrients become depleted, so the farmer...
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Modern Agriculture (Encyclopedia of Global Resources)
As populations continued to grow, there was a need to select and produce crops with higher yields. The Green Revolution of the twentieth century helped to make these higher yields possible. Basic information supplied by biological scientists allowed the agricultural scientists to develop new, higher-yielding varieties of numerous crops, particularly the seed grains that supply most of the calories necessary for maintenance of the world’s population. These higher-yielding crop varieties, along with improved farming methods, resulted in tremendous increases in the world’s food supply. The new crop varieties also led to an increased reliance on monoculture. While the practice of growing only one crop over a vast number of hectares has resulted in much higher yields than planting multiple crops, it has also decreased the genetic variability of many agricultural plants, increased the need for commercial fertilizers, and produced an increased susceptibility to damage from a host of biotic and abiotic factors. These latter two developments have resulted in a tremendous growth in the agricultural chemical industry. Today’s modern agricultural unit requires relatively few employees, is highly mechanized, devotes large amounts of land to the production of only one crop, and is highly reliant on agricultural chemicals such as fertilizers and pesticides.
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Agricultural Diversity (Encyclopedia of Global Resources)
With all the diversity that has occurred in modern agriculture, the industry is subdivided into many different specialties. On the animal side of the industry, there is the beef industry, which deals with the production of beef cattle; the dairy industry, which focuses on the production of dairy cattle, milk, and milk products; the horse industry, which produces horses for work, sport, or pleasure; the sheep and goat industry; the swine industry, which deals with the production of pigs and hogs; and the poultry industry, which is concerned with the production of commercial birds and bird products such as eggs. Those agricultural industries that deal with plants include agronomy, the production of field crops (wheat, cotton, and so on); forestry, the growth and production of trees; and horticulture. Horticulture is subdivided into pomology, the growth and production of fruit crops (oranges, apples, and so on); olericulture, the growth and production of vegetable crops (tomatoes, lettuce); landscape horticulture, the growth and production of trees and shrubs that are used in landscape design; and floriculture, the growth and production of flowering plants used in the floral industry.
The various agriculture industries produce a tremendous number of different agricultural products. Those agricultural products that are derived from plants can be subdivided into timber products (such as lumber, furniture), grain products...
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Impact on Other Natural Resources (Encyclopedia of Global Resources)
While there have been tremendous increases in agricultural productivity through the use of modern agricultural practices, these same practices have had a significant impact on some other natural resources. Soil is one of the most overlooked and misunderstood resources. Most people think of soil as an inert medium from which plants grow. In reality, topsoil—that upper 15 to 25 centimeters of the Earth’s terrestrial surface in which nearly all plants grow—is a complex mixture of weathered mineral materials from rocks, partially decomposed organic molecules, and a large number of living organisms. The process of soil formation is very slow. Under ideal conditions, topsoil can form at a rate sufficient to produce a layer of about 1 millimeter thick when spread over 1 hectare per year. Under less favorable conditions, it can take thousands of years to produce this small amount of soil. With proper management, topsoil can be kept fertile and productive indefinitely. However, many agricultural techniques lead to the removal of trees and shrubs, which provide windbreaks, or to the depletion of soil fertility, which reduces the plant cover over the field. These practices have exposed the soil to increased erosion from wind and moving water, and as a result, as much as one-third of the world’s current croplands are losing topsoil faster than they can be replaced.
Because plants require water in order to grow,...
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Current Trends in Agriculture (Encyclopedia of Global Resources)
The development of biofuels, fuels produced from plants, such as corn and soy ethanol and cellulosic ethanol (produced from inedible portions of plants), has been encouraged by the need to find a substitute for expensive and environmentally harmful fossil fuels. However, the fluctuating price of oil has caused this industry to advance in fits and starts. Critics point out that biofuels use cropland that otherwise would be producing food, and the rise of the electric car could speed the decline in the use of fossil fuels, making biofuels obsolete.
The next major development in agriculture will be the biotechnical revolution, in which scientists will be able to use molecular biological techniques to produce exotic new crop varieties. In the future, perhaps agricultural scientists will be able to use these techniques to develop crop plants that can be produced, processed, and distributed with less impact on other resources. Many scientists feel nanotechnology, the ability to restructure matter at the level of molecules and atoms, could meet the need for growth in agriculture through improving the production of both plants and animals and improving both the safety and quality of food. A wide range of developed and developing countries, from the United Kingdom to Iran to India, are providing funding to scientific laboratories to develop nanotechnology products. The potential products range from antibacterial agents...
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Commercial Impact of the Agriculture Industry (Encyclopedia of Global Resources)
Worldwide, some 45 percent of the population makes a living through agriculture, both subsistence and commercial. This also includes those people hired by the agriculture chemical companies, those companies that produce or sell agriculture implements and machinery, processing and canning plants, and wholesale and retail marketing firms, such as grocery stores. There are some eight thousand different agricultural products on the market, and while agriculture is big business, it amounts to less than 5 percent of the gross domestic product of all nations. Approximately one-third of the land worldwide is used for agriculture.
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Further Reading (Encyclopedia of Global Resources)
Akinyemi, Okoro M. Agricultural Production: Organic and Conventional Systems. Enfield, N.H.: Science Publishers, 2007.
Brody, Aaron L., and John B. Lord, eds. Developing New Food Products for a Changing Marketplace. 2d ed. Boca Raton, Fla.: CRC Press/Taylor & Francis, 2008.
Field, Thomas G., and Robert E. Taylor. Scientific Farm Animal Production: An Introduction to Animal Science. 9th ed. Upper Saddle River, N.J.: Prentice Hall, 2008.
Janick, Jules. Horticultural Science. 4th ed. New York: W. H. Freeman, 1986.
Kipps, M. S. Production of Field Crops: A Textbook of Agronomy. 6th ed. New York: McGraw-Hill, 1970.
Metcalfe, Darrel S., and Donald M. Elkins. Crop Production: Principles and Practices. 4th ed. New York: Macmillan, 1980.
Southgate, Douglas, Douglas H. Graham, and Luther Tweeten. The World Food Economy. Malden, Mass.: Blackwell, 2007.
Weis, Tony. The Global Food Economy: The Battle for the Future of Farming. New York: Zed Books, 2007.
Wojtkowski, Paul A. Agroecological Economics: Sustainability and Biodiversity. Boston: Elsevier/Academic Press, 2008.
Agriculture and Agri-Food Canada. Agri-Industries. www4.agr.gc.ca/AAFC-AAC
U.S. Department of Agriculture. Agriculture. www.usda.gov/wps
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