208 ANNUAL REPORT OF THE Off. Doc. 



what could bo accomplished 'by the farmer, on the farm, or the 

 gardener, in his garden, with no assistance other than printed direc- 

 tions, and usually without comprehending, excepl in a very vague 

 way, the reasons for the various operations necessary. If the tests 

 had been carried on by carefully selecting the experimenters, sup- 

 plying the cultures only to trained bacteriologists, botanists, and 

 men of similar professions, the results might have been in some ways 

 more uniform. This course would not, however, have solved the 

 practical problem, namely, the adaptability of the culture method to 

 general use; therefore, no discrimination of any sort was practiced, 

 all applicants for cultures being treated alike. The results ob- 

 tained have already been made public in tw r o bulletins issued by the 

 Department of Agriculture (Bulletin No. 71 of the Bureau of Plant 

 Industry, and Farmers' Bulletin No. 214) and show that, under the 

 proper conditions, the use of cultures is decidedly profitable and that 

 the dry culture method is eminently practicable under average farm 

 conditions. Very recently a supplementary bulletin has been issued 

 (Part IV of Bulletin No. 72, Bureau of Plant Industry) giving in con- 

 densed form specific information as to where the use of cultures may 

 be profitable, and where they are of no benefit; also furnishing di- 

 rections for making up large amounts of culture material for field 

 use from the pure culture "starter." 



Eighty per cent, of the reports which were of such a character 

 that a direct comparison could be made showed a gain from inocu- 

 lation, and reports are constantly coming in which at least maintain 

 this average. Of course, there were many failures from definitely 

 stated causes such as drought, flood, poor seed, weeds, improper 

 cultivation, etc., w r hich are not reckoned in the percentage given 

 and it must be recognized that there is no "magic" in the cultures 

 to overcome failures resulting from such causes. Neither do the 

 bacteria supply all the conditions for growth; they are active only 

 in storing up nitrogen, and where soil is so deficient in potash and 

 phosphorus as to require these elements inoculation will not act 

 as a substitute. The need for lime upon acid soils is another factor 

 of great importance. The legumes generally prefer a soil rich in 

 lime and a partial explanation for this lies in the fact that the 

 bacteria can not properly perform their w r ork in an acid soil; they 

 either fail to produce nodules, or the nitrogen fixation is greatly 

 reduced. 



The question now arises, "What are the proper conditions" under 

 which it may be advantageous to inoculate seed or soil? 



This will depend largely upon previous experience in growing 

 legumes on the same soil. If no difficulty has been experienced in 

 getting a stand, and the crop has been up to the average it is usually 

 safe to assume that the soil is already adequately supplied with 



