232 ECONOMIC PLANTS 



bacteria without which the plant cannot thrive are 

 absent from the soil. One way to inoculate the soil 

 is to scatter broadcast over the field some soil from 

 a successful old alfalfa field. If this is not practicable, 

 bacteria cultures may be obtained from the Depart- 

 ment of Agriculture and the seed inoculated. 



Legumes as Forage Crops. - - There are other legumes 

 that, while not well fitted for hay because of being 

 annuals, are yet exceedingly valuable for forage crops ; 

 that is, as green food for stock. Crimson clover is one 

 of these which may be soiled ; that is, fed green, or cut 

 and dried and used for early feeding. Vetch, especially 

 winter vetch, when sown with rye or wheat, is valuable 

 for forage, as is also the field pea when sown with oats. 

 The latter is especially good for milch cows if soiled and 

 used for sheep when cured. The soy (soja) bean may 

 be profitably used either for soiling or silage, especially 

 in the south. In some western states it is fed on the 

 land to hogs and sheep. 



VEGETABLES AND FRUITS 



Under the general name of vegetables are included 

 those plants used for culinary purposes which are culti- 

 vated in the gardens. They may be conveniently 

 classified, according to the part of the plant used, into 

 tuber, bulb, root, seed, and leaf plants. 



Tubers. A tuber is an underground stem. (See 

 page 131.) The only tuber that is used for human food 

 in this country is the common potato. The Jerusalem 

 artichoke is a tuber much used as a vegetable food in 

 some countries, but it has never found great favor in 

 the United States. 



The Potato. This vegetable, whether grown in 



