LEGUMES AND INOCULATION 



171 



on a soil where there have been no clover tubercles, he 



must place the clover germs there (Fig. in). He can do 



this by sowing in that place soil from a field where clover 



has turned loose its millions of germs. If he wishes to 



grow alfalfa, he must likewise sow on the new field soil 



from an old alfalfa field. 



Inoculation is the name 



given to this placing of 



the proper germs where 



they can form tubercles. 



To inoculate a legume is 



to bring the proper germs 



to its roots (Figs. 112, 113, 



114). 



How to inoculate leg- 

 umes. Legumes can be in- 

 oculated in several ways, 



FIG. 113. ROOTS OF SOY BEAN, 

 NOT INOCULATED 



(i) by sowing soil, (2) by 



dipping the seed in water 



mixed with this soil, or (3)' 



by mixing the seed with 



a special preparation made 



originally from ground-up tubercles of a plant like that 



to be grown. 



Using the proper soil. This is a reliable method of 

 inoculating the soil. Care must be taken not to use 'soil 

 that has in it seeds of bad weeds or that contains the germs 

 of serious plant diseases. Promptly cover inoculated seed 

 or soil used for inoculating legumes, for much sunshine 

 will kill the germs. 



