168 CHAPTER X 



SOYBEANS iSojarmx). 



The soy bean in South Africa is not as important a crop 

 as the cowpea. It seems adapted to a more intensive phase of 

 farming than prevails in this country. Most varieties shed 

 their seeds a few days after maturity and the leaves fall very 

 early. Chiefly for these reasons cowpeas are usually grown in 

 the Union instead of soy beans. 



History. — It has been cultivated for many centuries in 

 the East, particularly in Manchuria, China and Japan, where 

 it is grown largely as human food and for the oil extracted from 

 the seed. A large quantity of the seed is exported from Man- 

 churia to Europe and America, where it is crushed, the bean 

 cake being used as a feeding concentrate and the oil for indus- 

 trial purposes, generally in the manufacture of explosives. In 

 America it is grown principally as a green-manurmg crop, for 

 fodder and for the gram. A number of varieties were imported 

 into the Orange Free State as early as L904, grown on the 

 experimental farms and then distributed among the farmers. 

 The difficulty of harvesting the seed, because of its tendency 

 to shatter when mature, has no doubt retarded its popularity. 



Description. — It is one of the most productive as regards 

 seed of any legume adapted to temperate climates. The flowers 

 are small, white or purple, borne on short axillary racemes. The 

 pods are short, 1 to 3 inches long, usually compressed, and bear 

 two to four seeds each. The number of pods per plant varies 

 from thirty to four hundred. They may be grey, tawny or 

 black, and always very pubescent. The colour of the seed, 

 which in shape is globose to elliptical, may be yellow, green, 

 brown or black. The embryo may be yellovv' or green. It is a 

 summer annual, determinate in growth, i.e.. the whole plant 

 reaches maturity as the pods ripen, and no further growth takes 

 place. The whole plant is somewhat hairy, the stems upright, 

 well defined, somewhat woody and from 6 inches to 6 feet in 

 height. The leaves turn yellow as the pods mature, and have 

 all fallen by the time the pods have ripened. 



Since the uses of the soy bean and cowpea are agronomi- 

 cally much the same in Soutli Africa, the following comparison 

 may be of value in differentiating between them : — 



Soy beans are determinate in growth, while cowpeas are 

 indeterminate ; the former will stand slight frosts, the latter 

 cannot. Soy beans are said to be more drought resistant than 

 cowpeas. Soy bean seed has a nutritive ratio of nearly 1 :2, 



