The Bulletin. 9 



if the precautions given above are observed, satisfactory results 

 should be obtained by its use with alfalfa. 



By Artificial Cultures. — The ' artificial cultures that have been 

 placed upon the market during the past few years have generally 

 been found to yield unreliable results, even when used according to 

 directions, and in most cases have proven absolutely worthless. Espe- 

 cially has this been found to be the case with those that were sent out 

 in dried cotton; because of defects in the method which largely de- 

 feated its purposes. At present, so far as the writer is aware, there 

 are no cultures prepared by this method on sale in the markets that 

 could be recommended as thoroughly reliable. The National De- 

 partment of Agriculture has, however, distributed during the past 

 year in sealed bottles pure active cultures in liquid medium that were 

 poor in nitrogen, and which yielded very satisfactory results where 

 used. 



By Natural Inoculation. — On soils already abundantly supplied 

 with the specific bacteria desired, or on soils possessing great fertility, 

 inoculation will generally prove of little or no benefit ; because, in the 

 first instance, inoculation is already complete; while in the second 

 case it is unnecessary, as the plants can get from the large available 

 supply of the soil all the nitrogen needed for their growth, and proba- 

 bly do it much easier in this way, especially where the supply is 

 abundant, than through the intervention of bacteria. In fact, with 

 very favorable surroundings the bacteria themselves largely lose their 

 power of forming nodules on the roots of the host plants ; hence, it is 

 often observed that legumes growing on very rich soil frequently 

 have few nodules to develop on their roots. In other words, the bac- 

 teria, like some people, grow indolent when surrounded by plenty 

 and hence relieved of the necessity for work. When alfalfa, or any 

 other leguminous crop, is grown upon a piece of ordinary land in 

 good physical condition it will gradually become inoculated with the 

 specific nitrogen-gathering bacteria essential for the best growth of 

 that particular crop. It may be found that in the first year only a 

 few plants have naturally become inoculated, while in the second 

 year a larger number would be found, and in the course of a few- 

 years, if the same legume were continuously planted on the same piece 

 of land, it would become thoroughly inoculated. The chief objection, 

 however, to this method of inoculation is the great expense and 

 trouble incurred by several crop failures before inoculation is com- 

 plete enough to be reasonably assured of success in growing the 

 legume desired, when other conditions are favorable. 



SOILS. 



Favorable Soils. — ^Although alfalfa is adapted to a wide range of 

 soils, it seems to do best generally upon a fine sandy loam soil well 

 supplied with plant food, especially lime, and possessing a rather 

 open, porous and well-drained subsoil, so that the roots can penetrate 



