FIELD EXPERIMENTS. 33 



The soy bean is an erect, annual plant, with branching, 

 hairy stem, trifoliate, more or less hairy leaves, rather incon- 

 spicuous pale lilac or violet colored flowers, and broad, two to 

 five-seeded pods, covered like the stem, with stiff, reddish hairs, 

 The seeds vary in color from whitish and yellowish to green, 

 brown and black; and in shape from spherical to elliptical and 

 more or less compressed. 



The seeds are self pollinated, and on this account are sure 

 to produce seeds wherever the plants reach matin-ity. 



CONDITIONS OE GROWTH. 



It is believed in Japan that in northern climates, soils of a 

 rather strong character are best adapted to the soy bean. It 

 is usually sown about the end of May, and when used for hay 

 is cut early in August. In both Europe and America it has 

 been found to thrive best on soils of medium texture that are 

 well supplied with potash, phosphoric acid, and lime. It suc- 

 ceeds very well, ho^vever, on comparatively light soils, often 

 giving an abundant crop on soils too poor to grow clover. 



The soy bean requires about the same temprature as corn. 

 Professor Brooks says that the earlier sorts will mature in 

 Massachusetts with as much certainty as will the earlier varie- 

 ties of corn. 



As a general thing, the soy bean is not so easily injured by 

 frost as the common field or garden varieties of beans, and 

 hence it can be planted earlier in the spring and can also be 

 left in the field later in the autumn. 



EERTIUZING AND CULTURE. 



Like all leguminous plants, the soy bean, through the aid 

 of root tubercle organisms, acquires atmospheric nitrdgen. 

 When the soy bean was first introduced into America it did 

 not form root tubercles. In order to insure the growth of the 

 root tubercles it is necessary to use seed that has been inocu- 

 lated, or to inoculate the soil with the proper organism. This 

 last is readily done by applying broadcast a small amount of 

 soil taken from a field where soy beans developing root tuber- 

 cles have been grown. At this Station no tubercles form.ed on 



