230 ALFALFA FLEMING IN AMERICA. 



very soon he has the land all inoculated so that he 

 can not sow a field anywhere that the bacteria do 

 not find the young plants. And when once alfalfa 

 has grown on a field the inoculation persists for 

 several years after it is plowed up. We do not 

 understand these things yet. Maybe we never will. 

 It is mysterious that even the use of manure not 

 made from alfalfa hay, 'on a farm where alfalfa has 

 never grown, should often result in inoculating the 

 soil with alfalfa bacteria. There is no doubt of this 

 fact. I have seen it repeatedly. 



Inoculation with Soil. Soil from a field where al- 

 falfa has grown, or sweet clover (melilotus) has 

 grown, or burr clover has grown, distributed over 

 the new alfalfa field, is a safe and sure inoculation. 

 Some suggest the danger of infecting the new field 

 with weeds or with diseases by this practice. That 

 danger is remote. One hundred pounds of soil will 

 inoculate an acre quite well if it has good distribu- 

 tion. That much soil is taken from a small place 

 of only a few square feet. It would contain few 

 seeds. A few sweet clover seeds in the soil do no 

 harm to the alfalfa anyway. No other weeds are 

 likely to be found where good clover or alfalfa is 

 growing. 



Method of Using Soil. How to best manage this 

 soil inoculation! Take the soil from the surface 

 down as deep as the land is well filled with roots. 

 Dig it and carry it home and put it on the barn 

 floor. Spread it, not too thin, and work it over 

 from time to time to help it dry and make it fine 



