268 THE FORAGE AND FIBER CROPS IN AMERICA 



(3) The field may be grazed and the remaining stubble and 

 the added manure subsequently plowed under. 



(4) The crop may be mowed for hay and the stubble only 

 plowed under. 



Which of these methods will be best will depend somewhat on 

 the character of the soil, the amount of live stock available, 

 and the system of farm management. On heavy clay soils the 

 plowing under of a large growth of green cowpeas may be 

 desirable when on a light, sandy soil it might make the soil 

 temporarily too loose. Leaving a crop to decay on the surface 

 may be desirable where the soil is sandy and liable to wash 

 during the winter. 



331. History. The cultivation of cowpeas by the orientals 

 dates back into centuries. The plant was used for forage for 

 domestic animals while its seeds became an article of human 

 diet. It was introduced into the southern states of North 

 America by a South Carolina planter who obtained a small 

 quantity of seed from the captain of a trading vessel from India 

 or China early in the eighteenth century. 



II. SOY BEAN 



332. Description. The soy bean is an upright, rather woody 

 annual, growing two to three, rarely four feet high. The three 

 large leaflets, often six inches long and four inches wide, are 

 borne on leaf stalks not uncommonly 10 to 12 inches in length, 

 giving the plant the appearance of being much branched. The 

 leaflets are a large part, and the most valuable part of the whole 

 plant when used for forage, and are liable to be lost in curing 

 for hay. The small, inconspicuous lilac or violet flowers are 

 borne in the axils of the leaves, and are self-pollinated. The 

 pods are said to be two to five-seeded. Pods with more than 

 three seeds are, however, exceedingly rare. Haberlandt reports 

 that plants grown in Austria-Hungary bore about 200 pods and 

 450 seeds each. The valves of the pods twist as they open, 



