Advances and Trends in the Agricultural Sciences

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Advances and Trends in the Agricultural Sciences

Overview

After their emergence as a distinct realm of professional scientific research in the nineteenth century, the agricultural sciences continued their impact in the first half of the twentieth century. Led by developments in genetics, animal nutrition, bacteriology, and agricultural chemistry, farmers were able to produce more food from existing lands, and also to extend their production into lands that had previously been beyond the realm of cultivation. As a consequence, successful agricultural production became increasingly dependent upon access to the information and capital associated with the agricultural sciences.

Background

Although most developments in nineteenth-century agricultural sciences originated in western Europe, three important pieces of legislation shifted the stage to the United States by the early twentieth century. The Hatch Act of 1887 provided funds for the establishment of agricultural experiment stations in each American state and territory, the Adams Act of 1906 doubled these stations' funding and allowed for increased emphasis on basic research in the agricultural sciences, and the Smith-Lever Act of 1914 supported agricultural extension programs and thereby lessened scientists' duties to work directly for farmers. The United States Department of Agriculture thus became one of the world's centers for scientific research, using a network of extension agents, publications, and, by the 1930s, weekly radio shows to disseminate scientific knowledge among practicing farmers and to the public at large. In the United Kingdom the Development Act of 1910 and similar bills also authorized increased public funding for basic research in the agricultural sciences at the university level, most notably at Cambridge. In Germany, meanwhile, the relative position of the agricultural sciences declined in the face of economic hardships, political turmoil, and diminishing funding for universities and research institutions.

The rediscovery of Gregor Mendel's (1822-1884) theories on genetics was perhaps the most important development in the agricultural sciences at the turn of the century. The American plant breeder Luther Burbank (1849-1926) developed hundreds of new plant varieties without aid of the Mendelian theory, but other scientists dismissed his work as unscientific or unimportant. Supporters of the Mendelian theory turned instead to the systematic inbreeding of desirable varieties as a more predictable method. In 1918 Donald F. Jones (1890-1963) of the Connecticut Agricultural Experiment Station discovered that by crossing four pure-bred lines over two generations, new corn varieties could be produced that accentuated desirable traits like disease resistance, climatic adaptation, and higher yield. By 1950 hybrid seeds were commonly used for other crops as well.

Plant breeding took a different turn in the Soviet Union, where T. D. Lysenko's (1898-1976) explicitly anti-Mendelian interpretation of genetics was intended to fit Marxist ideology and Stalinist land policies. His theory of "vernalization" involved attempts to adapt Russian crops to local growing conditions, but it resulted in the purge of Mendelian geneticists and an increasing the gap between western and Soviet food production.

In animal breeding, researchers found increasingly efficient strategies for selecting desirable traits such as physiological response to work, efficiency of feed utilization, and resistance to disease. The American Breeders' Association also gained national attention for its work popularizing the controversial field of eugenics. Artificial insemination techniques, common in the United States by the 1940s, permitted the rapid emergence of new livestock breeds tailored for the consumer markets.

Discoveries in biochemistry and animal nutrition changed ideas on animal feeds. Elmer Vernor McCollum (1879-1967) of the Wisconsin Agricultural Experiment Station discovered that trace minerals and organic substances, now known as vitamins, are essential in animal nutrition. By mid-century researchers had discovered that the addition of synthetic hormones to animal feeds could improve feed efficiency, regulate sexual activity, and stimulate lactation in dairy animals. In the process, poultry science, dairy science, and veterinary medicine dramatically altered the traditional work of animal husbandry.

Beginning with Louis Pasteur's (1822-1895) mid-nineteenth century research on silkworm parasites, anthrax vaccines, and microbes in foods and dairy products, the science of bacteriology also emerged from work on agricultural topics. Control of bacteria in dairy and other products virtually eradicated one of the primary causes of human disease and improved the safety of commercial foodstuffs. Soil bacteriology was another important branch of the field, led by Selman Waksman's (1888-1973) discovery of streptomycin and other antibiotics derived from soil microbes. The Dutch scientist Martinus Willem Beijerinck (1851-1931) found applications for soil microbes in the industrial production of yeast, alcohol, and various chemicals.

Though agricultural chemists were not as dominant in the agricultural sciences as in the nineteenth century, the chemicalization of agriculture continued unabated. Well aware that the supply of Chilean nitrates, the major source of nitrogenous fertilizers, was in decline, many scientists sought a solution to the western world's "nitrogen question." By 1913 German chemist Fritz Haber (1868-1934) and his colleague Carl Bosch (1874-1940) developed a process that used very high temperatures and pressures to synthesize ammonia from atmospheric nitrogen and hydrogen. American consumption of synthetic fertilizers had increased more than tenfold between 1900 and 1945, and the market for natural organic fertilizers virtually vanished.

Farmers also turned to powerful chemicals to control pests, such as calcium cyanides used against rodents and the arsenates used to fight the cotton boll weevil. During World War II scientists devoted great energy into finding chemicals that could kill the insects that threatened soldiers with typhus and malaria. The resultant research on DDT (dichloro-diphenyl-trichloroethane) had promising implications for pest control on the farm. By the late 1940s farmers, governments, and private industries all promoted DDT and other agricultural chemicals as panaceas that brought both higher yields and pest control with no apparent risk to human health. The broadleaf herbicide 2,4-D (2,4-dichlorophenoxyacetic acid), developed in 1941, was also significant—it has properties that mimic plant hormones and thus artificially speed up the metabolism of weed plants to force them to "starve themselves" by using up all of their stored food.

Impact

Developments in the agricultural sciences continued to increase farm productivity, reduce threats of disease, and permit the cultivation of previously untilled lands, and thereby contributed to the rapid growth of the world's population. At the same time, the percentage of the world's population engaged in agricultural pursuits declined steadily.

These circumstances suggest that the agricultural sciences helped accelerate the ascendancy of the farmers and businesses with better access to the knowledge and capital required to use hybrid seeds, scientific feeds, pesticides, herbicides, and similar goods. Farmers' skill and experience became a less important factor in their success, and declining rural populations also reduced farmers' influence in the political and cultural arenas.

These trends also signaled a relative decline in the professional significance of the agricultural sciences. At the beginning of the century, agricultural scientists at government agencies like the USDA and institutions like the land grant universities and agricultural experiment stations held important positions within the scientific community and were often influential in public policy debates. Major discoveries in genetics, bacteriology, public health, and other disciplines emerged from laboratories of the agricultural scientists. Scholars and public officials alike expressed great enthusiasm for the agricultural sciences, confident that safe and abundant food supplies would soon be available to all.

By the middle of the century, however, a small number of critics expressed concern about the increasing interconnections between farming and its costly inputs. Yet agricultural issues also often fell out of the public dialogue, as much of scientific research shifted to the large universities associated with "Big Science." In the Atomic Age research in plants and animals lacked the same status in the public imagination as physics, chemistry, and aeronautics.

The agricultural sciences also had growing significance for farmers of non-Western nations in the early twentieth century. Rural elites and colonial administrators used the rhetoric and techniques of science in order to establish experiment stations, to develop hybrids, and to adapt local farming techniques in ways that contributed to the commodification of tropical nature. As elsewhere, the expansion of agricultural science in the European colonies increased production to such a degree that those who were well connected and well capitalized could maintain profitable access to the marketplace.

The expansion of the hybrid corn and agricultural chemicals illustrate some of these concerns. Hybrid corn became commercially viable in the United States in the 1930s, and it expanded so rapidly that, by 1943, hybrid seeds were used on 90% of the American corn acreage. Yet inbred hybrids lose their desirable traits in just one generation, so farmers have little choice but to purchase their seed from increasingly large and powerful seed conglomerates. Though they might have developed alternative seed technologies, government-funded institutions like experiment stations gradually abandoned research in crop genetics and left it to the control of private sector seed companies. These companies have developed strains that stand more upright, allowing more seeds to be planted per acre, and hybrid plants that have enough uniformity and durability to make them suitable for farm machines like harvesters and combines. Similarly, farmers have become ever more dependent on artificial fertilizers and chemical pesticides in order to keep their lands under virtually continuous cultivation. Though farmers today face smaller risks of crop failure, their increasing specialization in fewer and fewer profitable commodities has led to an ominous reduction in the diversity of the world's germplasm.

MARK R. FINLAY