230 ALFALFA FARMING 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 
