374 FIELD CROPS 



THE SOY BEAN 



497. Origin and Description. Much that has been said 

 regarding the cowpea apphes equally well to the soy bean. 

 This plant was introduced into the United States nearly one 

 hundred years ago from Japan and China, where, Hke the 

 cowpea, it has been cultivated for many centuries, but it 

 has come into prominence only recently. The growth is 

 usually erect, with stiff, hairy stems and numerous large, 

 broad leaves. The leaves, which are borne on long stems, 

 consist of three leaflets. The leaflets are from 2 to 3 inches 

 long; and the width is about two thirds of the length. The 

 flowers are small, clustered in the axils of the leaves, and are 

 usually pale purple or lilac in color. The short, hairy pods 

 contain two or three round or slightly flattened seeds. The 

 seeds are usually black, green, or yellow; and range in diam- 

 eter from one eighth to one quarter of an inch. The size 

 of the plant, the habit of growth, and the size and color of 

 the seeds vary even more than these characters of the cowpea. 

 While most of the varieties are erect and vary in height 

 from 1 to 4 feet, some sorts have small seeds, small leaves and 

 a trailing habit, the vines reaching a length of several feet. 

 The most prominent varieties are Mammoth, Ito San, Medium 

 Yellow, Hollybrook, and Wilson. 



498. Importance. The soy bean does not yet occupy 

 a very prominent place in the United States, though its 

 importance is increasing rapidly. In China and Japan it is 

 one of the most important crops for the production of grain 

 and oil. As the plant is less easily injured by frost than the 

 cowpea, it can be grown farther north. It is most useful 

 along the northern border of the section where cowpeas are 

 grown, from Kansas, Kentucky, and Maryland northward. 

 The soy bean grows very well on poor and sandy lands, and 

 is sure to become as important for the building up of poor 

 soils and for forage in this region as the cowpea now is 

 farther south. 



