184 



plants) only 761 pounds of hay. This is a gain of at least 

 3,296 pounds of hay per acre as the result of inoculation. 



Seed of hairy vetch inoculated with vetch Nitragen pro- 

 duced hay at the rate of 3,270 pounds per acre, against 564 

 pounds with ordinary or untreated seed. This is an increase 

 of 2,706 pounds of hay per acre as the result of inoculation. 



The cost of inoculation, using Nitragin as above, was at 

 the rate of 12.25 per acre, leaving a large profit. 



In an earlier experiment here hairy vetch was inoculated 

 with soil from an old vetch field, wihout expense except a 

 small item for labor. This home grown inoculating material 

 effected an increase of 2,308 pounds of hay per acre. 



A field once inoculated, whether naturally or artificially, 

 remains inoculated for years. 



As a general rule, each division or genus of leguminous 

 plant has its own specific or adapted germ. 



Nitragin is very perishable especially in warm weather 

 and this may cause frequent failure in using it. 



Natural agencies are constantly at work spreading root 

 tubercle bacteria and inoculating soils. If given sufficient 

 time (several years) most legumes will probably develop 

 tubercles without help from man. Artificial inoculation 

 brings quicker success in the culture of rarely grown legumes. 



Inoculated hairy vetch yielded slightly less dry material 

 in the above-ground portion and a considerably smaller 

 weight of roots than nearly mature rye. 



However the inoculated vetch contained in both tops and 

 roots a much higher percentage of the valuable element, 

 nitrogen, than did rye, and also more than did non-inoculated 

 vetch plants. 



The crop on one acre contained in tops, stubble and roots 

 105.5 pounds of nitrogen in the case of inoculated hairy vetch, 

 only 26 pounds in the case of rye, and still less in non-inocu- 

 lated vetch plants. This excess of 79.5 pounds of nitrogen 

 stored up by vetch explains the superior fertilizer and food 

 value of hairy vetch over rye. . 



Of the total nitrogen in healthy plants of crimson clover 

 and hairy vetch, less than one- fifth was contained in the roots 



