282 STATE BOARD OF AGRICULTURE. 



of these clusters not alonsr the stem, 'as is usually true with alfalfa nodules, 

 but at about the depth of the first plowing and on rootlets running out to a con- 

 siderable distance from the main root. This is only one of several instances 

 noted that suggests that some benefit is to be derived from one legume following 

 another. 



Soil, taken from a field upon which nodule-laden legumes had been grown 

 for some years with success, was first used as a means for distributing the proper 

 organism. This method usually proves very satisfactory from the standpoint of 

 securing the required inoculation, but it has its objectionable features. The 

 expense incurred in shipping and applying sufficient quantities of the germ-laden 

 soil to secure thorough inoculation is often high and the true germ content of 

 such soil is often questionable. These objections, however, are counteracted to 

 quite an extent by the effectiveness of the method. It is still being employed 

 and is serving at present as well as any method. 



In 1898, Nobbe conceived the idea that inoculation might be brought about 

 by using pure cultures, grown upon an artificial medium. He put his idea into 

 practice and sent out cultures of the organism isolated from each kind of legume. 

 These cultures were distributed in bottles on a nutrient medium. The use of 

 these cultures in Germany gave many favorable results. A new field had been 

 opened, a broader field, perhaps, than scientific men at that time realized. Tests 

 with his cultures were also made in the United States, with a less degree of 

 success than had been met with in Germany, but it failed to receive general 

 support because of the questionable results. 



It was not until the work of Dr. George T. Moore of the Laboratory of Plant 

 Physiology, Department of Agriculture, Washington, was given to the public 

 that general interest in this subject was again aroused. The material previously 

 mentioned, sent out by Nobbe of Germany, was a culture grown and distributed 

 upon a nutrient agar containing nitrogen. Dr. Moore aimed to cultivate the 

 organism on a nitrogen-free medium and by so doing claims to have succeeded 

 in developing a culture that is possessed of greater vigor, both in producing the 

 infection and in storin.g up free nitrogen. The cultures prepared in this way 

 ■were distributed to a large number of farms throughout the United States and 

 the results obtained by their use upon seed, given in Bulletin No. 71, Bureau 

 of Plant Industry, show successful inoculation and increase in productiveness 

 in 76 per cent of the cases tried, barring a large number of cases reported as 

 failures due to unfavorable conditions, including poor seed, poor seasons, weed 

 growth, etc. 



Closely following the apparent success achieved by Dr. Moore's cultures, several 

 commercial establishments placed inoculating material upon the market. The 

 merits of such cultures have not been established and they are not controlled 

 by the Government, consequently their real value is unknown. The person who 

 invests in such cultures is doing so entirely at his own risk — is taking a leap 

 in the dark; by paying a large price to try an experiment in which the actual 

 possibilities of gain have not been firmly established, he renders himself subject 

 to utter failure as well as possible success. 



Inoculating material, without question, will produce the desired infection 

 when applied under favorable conditions. What these favorable or unfavorable 

 conditions are, we are unable to indicate satisfactorily, for it should be remem- 

 bered that although ideas are formulating, we are still in the first stages of 

 the work and it would be presumptions to establish fast lines and binding con- 

 ditions. Such application of inoculating material, from an experimental stand- 

 point, in pots under glass and in small plots in the field, can be carried out very 

 successfully and very flattering results are obtained. Naturally enough, workers 

 are led to expect similar returns from their efforts when directed to larger areas 

 and in a practical way, forgetting the number of unknown conditions which creep 

 in. It is difficult also to determine whether fields require these inoculations 

 or not, since not only the constituents of the soil, the weather elements, and 

 drainage enter for consideration, but the very history of a field must be con- 

 sulted. The idea in mind when legumes are sown is to increase the fertility by 

 adding nitrogen and humus, and this can be done only by conforming to the 

 controlling influences concerning which we are in such dense ignorance. 



In Table II of Dr. Moore's Bulletin No. 71, where "Reports of Experiments 

 with the Principal Leguminous Crops" are given, we find one column, No. 3, 



