728 Soil Inoculation in the United States, [march, 



a few exceptions. If the only source of nitrogen, therefore, is by 

 dissolving the bacteria, the benefit to the plant will be little or 

 nothing should the nodules continue to be filled with the 

 unbranched rods, and the presence of nodules upon the roots 

 may even be a detriment. Dr. Moore observes that too little 

 attention has been paid to this point, and states that there is no- 

 question that frequently organisms producing nodules have lost 

 the power of going into the branched condition, and thus while 

 preventing their destruction by the plant, they defeat the very 

 object for which they are supposed to be so valuable. Thus if 

 the organisms be grown upon artificial media for a long time 

 where they are almost invariably in the rod condition, this form 

 becomes so firmly established that plants inoculated with such 

 cultures, although forming nodules, receive practically no benefit, 

 the nodules remaining firm and hard and furnishing no nitrogen 

 to the roots. The nature of the nodule-forming organism is 

 purely parasitic, and unless the plant can overcome its action, 

 it causes distinct harm. It is, however, possible for the nitrogen- 

 fixing bacteria to penetrate the roots of the plant, and, existing 

 in the branched form, to be of decided benefit without the forma- 

 tion of nodules or any external evidence of their presence. 



The reports received by the Department of Agriculture from 

 practical farmers as to the value of inoculation showed the 

 following results : — 



Crops. 



Total 

 reports. 



Inoculation 

 resulting 



in 

 definite 

 increase of 

 crop 



Failures 

 ascribed to 

 bad 



season, 

 poor seed, 

 weeds, &c. 



No increase 

 in crop : 



Organisms 

 already 

 present. 



No 

 evident 



advantages: 

 Nodules 



not formed. 



Alfalfa (lucerne) ... 



1,043 



„ 522 



287 



59 



175 



Red clover ... 



532 



302 



116 



84 



30 



Garden pea... 



184 



102 



32 



32 



18 



Common bean 



174 



85 



39 



23 



27 



Cow pea 



2^0 



I V 8 



42 



68 



32 



Soybean ... 



I29 



54 



22 



11 



42 



Hairy vetch 



53 



28 



13 



3 



9 



Crimson clover 



49 



27 



15 



4 



• 3 



Field pea ... 



22 



14 



4 



4 





Velvet bean 



10 



5 



3 



1 



1 



Alsike ... • ... 



7 



3 





2 



1 



Sweet pea ... 



7 



5 





2 





Berseem 



2 



1 







1 



Total 



2,502 



1,296 



574 



293 



339 



