Soybean (Glycine max), native to China, is a relatively new crop to the Great Plains, where there was no appreciable production prior to 1950. Since 1950, the production area has increased rapidly to more than 12 million acres in the U.S. Great Plains in 1998, which is about 18 percent of the national production area. The production is largely in the eastern Great Plains, due to the higher annual precipitation and the greater likelihood of rainfall during the critical pod elongation stage, which occurs in early August. Little soybean production occurs in the western Great Plains and the Canadian Prairie Provinces because of the short growing season (in the north), low annual precipitation, and low probability of rainfall during early August. Major production problems are water and high-temperature stress during the growing season. Only a few insect and pest problems cause sporadic yield losses. The most common pest problems are Phytophthora root and stem rot, bean leaf beetle, and soybean cyst nematode.
Since soybean is grown most widely in the eastern Great Plains, it does not overlap greatly with the region's large wheat acreage. Soybean is most commonly grown as a rotational dryland crop with corn, grain sorghum, and winter wheat, and is the third most important grain crop in the region, following wheat and corn. Soybean is produced as a cash crop, with the production being shipped by rail or truck to crushing plants. The major food end products are cooking oil, margarine, shortening, and emulsifiers. Soybean is also widely used as a high protein livestock feed supplement. Nonfood end uses include plastics and coatings, lubricants, diesel fuel substitute, carrier for pesticides, dust suppressant in grain handling, and printing ink.
The soybean production area within the Great Plains is concentrated in Nebraska and South Dakota, with 60 percent of the total, while production in Oklahoma and Texas is quite small. The highest yields–45 bushels per acre in 1998–are in Nebraska, largely because approximately one-third of the soybean production area is irrigated. Yields of approximately 25 bushels per acre are common in North Dakota, Oklahoma, and Texas. Soybean yields in the Great Plains average approximately 10 percent less than in the Corn Belt states, where higher, more uniformly distributed annual precipitation occurs.
See also INDUSTRY: Oilseeds.
Stephen C. Mason University of Nebraska-Lincoln
Wilcox, J. R., ed. Soybeans: Improvement, Production, and Uses. Madison WI: American Society of Agronomy, 1987.