The first domestication of soybean has been traced to the eastern half of North China in the eleventh century B.C. or perhaps a bit earlier. Soybean has been one of the five main plant foods of China along with rice, soybeans, wheat, barley and millet. According to early authors, soybean production was localized in China until after the Chinese-Japanese war of 1894-95, when the Japanese began to import soybean oil cake for use as fertilizer. Shipments of soybeans were made to Europe about 1908, and the soybean attracted world-wide attention. Europeans had been aware of soybeans as early as 1712 through the writing of a German botanist. Some soybean seed may have been sent from China by missionaries as early as 1740 and planted in France.
The first use of the word "soybean" in U.S. literature was in 1804. However, it is thought that soybean was first introduced into the American Colonies in 1765 as "Chinese vetches" . Early authors mentioned that soybeans appeared to be well adapted to Pennsylvania soil. An 1879 report from the Rutgers Agricultural College in New Jersey is the first reference that soybeans had been tested in a scientific agricultural school in the United States. For many years, most of the references to this crop were by people working in eastern and southeastern United States where it was first popular. Most of the early U.S. soybeans were used as a forage crop rather than harvested for seed. Most of the early introductions planted in these areas were obtained from China, Japan, India, Manchuria, Korea, and Taiwan.
For many years, soybean acreage increased very slowly. There were only 1.8 million acres in the United States in 1924 when the first official estimate became available. At that time, most of the crop was used for hay. It was not until the 1920's that soybean acreage expanded to any great quantity in the U.S. Corn Belt.
Before World War II, the U.S. imported more than 40% of its edible fats and oils. Disruption of trade routes during the war resulted in a rapid expansion of soybean acreage in the U.S. as the country looked for alternatives to these imports. Soybean was one of only two major new crops introduced into the U.S. in the twentieth century. The other major crop, Canola was initially developed in Canada and is now grown on some U.S. acres. Soybean was successful as a new crop because there was an immediate need for soybean oil and meal, its culture was similar to corn, and it benefitted other crops in a rotation.
Following World War II, soybean production moved from the southern U.S. into the Corn Belt. The major soybean producing states of Iowa, Illinois, Minnesota, Indiana, Ohio, Missouri, and Nebraska produced 67 percent of the U.S. total in 2003; the southern and southeastern states of Arkansas, Mississippi, North Carolina, Kentucky, Tennessee, Louisiana, Alabama, and Georgia produced 14 percent. Other states with significant soybean acreage are South Dakota, Kansas, Michigan, Wisconsin, and North Dakota.
A record 2.9 million bushel soybean crop was produced in 2001 on 74.1 million acres with an average per acre yield of 39.6 bushels. The leading soybean states are Iowa and Illinois. In 2003, Iowa had 10.6 million acres of soybeans while Illinois had 10.3 million. The highest state yield ever achieved was 50.5 bushels per acre produced by Iowa farmers in 1994.
The U.S. dominated world soybean production through the 1950's, 60's, and 70's, growing more than 75 percent of the world soybean crop. The U.S. was the major supplier of animal feed protein in the world during this period. A worldwide shortage of feed protein in the early 1970's led to the initiation of large-scale soybean production in several South American countries, most notably Argentina and Brazil. By 2003, the U.S. share of the world's soybean production had shrunk to 34 percent, while Argentina's and Brazil's had increased to 18 and 28 percent, respectively. Most of the land suitable for soybean production in Argentina has been put into production. Brazil has an estimated additional 100 million acres of land that can still be put into soybean production. This land, which comprises an area larger than the U.S. Corn Belt, is remotely located in the interior of the country and faces many obstacles to further soybean prodcution. One of the greatest problems is the lack of an efficient transportation system.
Early Uses. Soybeans were grown for centuries in Asia mainly for their seeds. These were used in preparing a large variety of fresh, fermented and dried food products that were considered indispensable to oriental diets. Soybeans were not used to any great extent for forage in Asia.
Early use of soybeans in the United States was for forage and to some extent, green manure. It was not until 1941 that the acreage of' soybeans grown for grain first exceeded that grown for forage and other purposes in the United States.
Present Uses. Soybeans are the United States' second largest crop in cash sales and the number one export crop. In 2003, the export value of soybeans was more than 9.7 billion dollars, or about one-sixth of all agricultural exports. Normally, more than half of the total value of the U.S. soybean crop comes from exports as whole soybeans, soybean meal, and soybean oil. About 40 percent of the world's soybean trade originates from the U.S.
China has become the largest single country customer for U.S. soybeans with purchases totaling nearly $3 billion. Mexico, the European Union, and Japan are the second, third, and fourth largest international markets, respectively. Major export markets for soybean meal are the Philippines and Canada. Mexico and Korea are large customers of U.S. soybean oil.
The majority of the soybean crop is processed into oil and meal. Oil extracted from soybeans is made into shortening, margarine, cooking oil, and salad dressings. Soybeans account for 80 percent or more of the edible fats and oils consumed in the United States. Soy oil is also used in industrial paint, varnishes, caulking compounds, linoleum, printing inks, and other products. Development efforts in recent years have resulted in several soy oil-based lubricant and fuel products that replace non-renewable petroleum products.
Lecithin, a product extracted from soybean oil, is a natural emulsifier and lubricant used in many food, commercial, and industrial applications. As an emulsifier, it can make fats and water compatible with each other. For example, it helps keep the chocolate and cocoa butter in a candy bar from separating. It is also used in pharmaceuticals and protective coatings.
The high protein meal remaining after extraction can be processed into soybean flour for human food or incorporated into animal feed. Soybean protein helps balance the nutrient deficiencies of such grains as corn and wheat, which are low in the important amino acids, lysine and tryptophan.
Use of vegetable proteins for human consumption continues to expand in the United States. They can be used as meat and dairy substitutes in various items. Most people are aware of the use of soy proteins in baby formula, weight-loss drinks, sport drinks, and as a low-fat substitute for hamburger.
Soy flour and grits, made from grinding whole soybeans, are used in the commercial baking industry to aid in dough conditioning and bleaching. They have excellent moisture-holding qualities that help retard staling in bakery products.
A 60-pound bushel of soybeans yields about 11 pounds of oil and about 48 pounds of meal.