AGRICULTURAL SCIENCES, THE

sciences dealing with food and fibre production and processing. They include the technologies of soil cultivation, crop cultivation and harvesting, animal production, and the processing of plant and animal products for human consumption and use. Food is the most basic human need. The domestication and cultivation of plants and animals beginning almost 10,000 years ago were aimed at ensuring that this need was met, and then as now these activities also fit with the relentless human drive to understand and control the Earth's biosphere. Over the last century and a half, many of the world's political leaders have recognized what India's Jawaharlal Nehru did, that Most things except agriculture can wait. Scientific methods have been applied widely, and the results have revolutionized agricultural production. Under the conditions of prescientific agriculture, in a good harvest year, six people can produce barely enough food for themselves and four others. Advanced technologies have made it possible for one farmer in the United States, for example, to produce food for more than 100 people. The farmer has been enabled to increase yields per acre and per animal; reduce losses from diseases, pests, and spoilage; and augment net production by improved processing methods. Until the 1930s, the benefits of agricultural research derived mostly from labour-saving inventions. Once the yield potentials of the major economic crops were increased through agricultural research, however, crop production per acre increased dramatically. Between 1940 and 1980 in the United States, for example, per-acre yields of corn tripled, those of wheat and soybeans doubled, and farm output per hour of farm work increased almost 10-fold as capital was substituted for labour. New techniques of preserving food products made it possible to transport them over greater distances, in turn facilitating adjustments among locations of production and consumption, with further benefits to production efficiency (see food preservation). From a global perspective, the international flow of agricultural technology allows for the increase of agricultural productivity in developed and developing countries alike. From 1965 to 1985, for example, world trade in grains tripled, as did net exports from the United States. In fact, by the 1980s more than two-fifths of U.S. crop production was exported, making U.S. agriculture heavily dependent upon international markets. Additional reading Charles Arntzen and Ellen Ritter (eds.), Encyclopedia of Agricultural Science, 4 vol. (1994), treats scientific, historical, social, and economic aspects. Development of the agricultural sciences is described in Gnther Franz (ed.), Deutsche Agrargeschichte, 6 vol. (196284), a general history of agriculture in Germany and central Europe from the beginning to the middle of the 20th century; Theodor Freiherr Von Der Goltz, Geschichte der deutschen Landwirtschaft, 2 vol. (190203, reissued 1963), a comprehensive history of agriculture; David Rindos, The Origins of Agriculture: An Evolutionary Perspective (1984); and Alan I. Marcus, Agricultural Science and the Quest for Legitimacy (1985), an account of the early history of agricultural science in the United States.Books covering education and research include Alfred Charles True, A History of Agricultural Education in the United States, 17851925 (1929, reprinted 1980), and A History of Agricultural Experimentation and Research in the United States, 16071925 (1937, reprinted 1970)both works were issued together in one volume as Alfred True on Agricultural Experimentation and Research (1980); Herbert M. Hamlin, Public School Education in Agriculture (1962); Edward D. Eddy, Jr., Colleges for Our Land and Time (1957, reprinted 1973); R. Douglas Hurt, American Agriculture: A Brief History (1994), evaluating American agriculture in historical perspective; and United States, Department Of Agriculture, The Agricultural Research Center of the United States Department of Agriculture (1952), a handbook, and three yearbooks, Science in Farming (1947), After a Hundred Years (1962), and Agriculture and the Environment (1991).Major aspects of the agricultural sciences are explored in Daniel J. Hillel, Out of the Earth: Civilization and the Life of the Soil (1991), a historical look at humankind's use of the soil; Allan G. Bogue, From Prairie to Corn Belt: Farming on the Illinois and Iowa Prairies in the Nineteenth Century (1963, reprinted 1994), a study of farming developments in the prairie states; J.S. Boyer, Plant Productivity and Environment, Science, 218:443448 (Oct. 29, 1982), an analysis of the genetic productivity potential of major plants; and Colin Tudge, Food Crops for the Future (1988), an exploration of potential new food crops through plant breeding. The interaction of agriculture and animals is presented in the works by Henry Prentiss Armsby, The Principles of Animal Nutrition (1903), a representative textbook from an earlier era of the agricultural sciences; by John R. Campbell and John F. Lasley, The Science of Animals That Serve Humanity, 3rd ed. (1985), a comprehensive publication on contemporary animal agriculture; and by Stanley E. Curtis, Environmental Management in Animal Agriculture (1983).Agricultural technology is discussed in Gnther Franz (ed.), Die Geschichte der Landtechnik in 20. Jahrhundert (1969), a publication on the history of agricultural engineering during the 20th century; United States Congress, Office Of Technology Assessment, Agricultural Postharvest Technology and Marketing Economics Research (1983), a technical memorandum; Jack Doyle, Altered Harvest: Agriculture, Genetics, and the Fate of the World's Food Supply (1985), an examination of the effects of biotechnology on agriculture; Robert C. Williams, Fordson, Farmall, and Poppin' Johnny: A History of the Farm Tractor and Its Impact on America (1987); and Wallace E. Huffman and Robert E. Evenson, Science for Agriculture: A Long-Term Perspective (1993), an assessment of research and education within the American agricultural science and technology system. Lennard Bickel, Facing Starvation: Norman Borlaug and the Fight Against Hunger (1974), is an account of the Nobel laureate agronomist's life and his experiments that led to the Green Revolution in developing countries. Cary Fowler and Pat Mooney, Shattering: Food, Politics, and the Loss of Genetic Diversity (1990), looks at another outcome of the Green Revolution. Dennis T. Avery, Global Food Progress 1991 (1991), catalogs the continuing benefits of the same revolution.Henry C. Taylor and Anne Dewees Taylor, The Story of Agricultural Economics in the United States, 18401932 (1952, reprinted 1974), chronicles the development of the field. Frederick H. Buttel, Olaf F. Larson, and Gilbert W. Gillespie, Jr., The Sociology of Agriculture (1990), reviews the literature for American agriculture. C.R. Carroll, Agroecology (1990), includes an overview of this discipline as well as basic concepts.Useful information on various agricultural sciences is included in Bibliography of Agriculture (monthly), listing agricultural materials from all over the world; and publications of the Food And Agriculture Organization Of The United Nations (fao), including The State of Food and Agriculture (annual), Animal Health Yearbook, and Plant Protection Bulletin (bimonthly). Gerhardt Preuschen John R. Campbell Stanley Evan Curtis The Editors of the Encyclopdia Britannica Major divisions The agricultural sciences can be divided into six groups. In all fields, the general pattern of progress toward the solution of specific problems or the realization of opportunities is: (1) research to more accurately define the functional requirements to be served; (2) design and development of products, processes, and other means of better serving these requirements; and (3) extension of this information to introduce improved technologies to the agricultural industries. This has proved to be a tremendously successful approach and is being used the world over. Soil and water sciences Soil and water sciences deal with the geological generation of soil, soil and water physics and chemistry, and all other factors relevant to soil fertility. Soil science began with the formulation of the theory of humus in 1809. A generation later, Liebig introduced experimental science, including a theory of the supply of soil with mineral nutrients. In the 20th century, a general theory of soil fertility has developed, embracing soil cultivation, the enrichment of soil with humus and nutrients, and the preparation of soil in accordance with crop demands. Water regulation, principally drainage and irrigation, is also included. Soil and water research have made possible the use of all classes of land in more effective ways, while the control of soil erosion and deterioration has made other advances even more striking. Because the amount of water available for plant growth is one of the major limiting factors in crop production, improved tillage and terracing practices have been devised to conserve soil moisture, and soil-management and land-use practices have been developed to increase the infiltration of snow, rain, and irrigation water, thereby reducing losses caused by runoff. Public and private research into chemical fertilizers and soil management have made it possible for farmers to aid nature in making specific soils more productive. Much has been learned about using crop rotation, legumes, and green manure for replenishing soil humus and nitrogen; determining and supplying the major and minor nutrient needs of crops; and managing soil under irrigation, including salt control. Techniques based on these findings have been put to use on farms to improve soil fertility and increase crop yields. Between 1940 and 1965, for example, farmers in the United States more than tripled their use of chemical fertilizers, resulting in increases of 50 to 150 percent in crop yields. Scientists have used many sophisticated techniques to unlock a vast storehouse of knowledge about plants. In one case, chemicals tagged with radioactive isotopes were employed to follow the processes by which plants take up soil nutrients to synthesize their fruits, grains, vegetables, nuts, flowers, and fibres.