Soybeans have become a major crop in Iowa. They are well adapted to Iowa’s climate and to general growing on the level Iowa soils where erosion is not a problem. The crop has many more uses than most crops, both on the farm and in industry.
Soybeans were first grown in Iowa for the home production of high-protein seed and hay. The seed has been used to substitute for purchased high-protein concentrates and the hay where legume hay is needed in the ration.
More than half of the acreage has been harvested as hay. During the 10 years, 1929-38, 64.5 percent has been harvested as hay, 30.5 percent for beans and the remaining 5 percent plowed under or grazed.
Dyas, E. S.
"Soybean production in Iowa,"
Bulletin P: Vol. 2
, Article 1.
Available at: http://lib.dr.iastate.edu/bulletinp/vol2/iss30/1