358 FIELD CROPS 



of July is the best time to sow alfalfa in the northern 

 states; the latter part of July or the first half of August is 

 preferable in the central section; in the South, September 

 is best. The proper time to sow varies to some extent from 

 year to year, as it is desirable to get the seed into the ground 

 when it contains plenty of moisture. If the land has been 

 prepared some weeks in advance and has been harrowed 

 after every shower so as to save all the rain which has fallen, 

 there is usually no trouble from this source, except in the 

 semiarid districts. Where the precipitation is light, spring 

 seeding is often best, in order to take advantage of the June 

 rains. There is usually more trouble from weeds with spring 

 seeding, unless special treatment was given the previous 

 year to clear the land of them. 



470. Sowing with a Nurse Crop. A nurse crop is not 

 commonly used with alfalfa, though in some sections its use 

 is regarded as good practice. On sandy land a nurse crop 

 may protect the young alfalfa plants from wind injury, but 

 it should be seeded very thinly. Generally, the use of a 

 nurse crop is more likely to result in injury than in benefit. 



471. Inoculation. When alfalfa is sown for the first time 

 in a locality, inoculation is quite often necessary to attain 

 success. This inoculation may be by means of soil from 

 an old alfalfa field, or by the use of pure cultures of the bac- 

 teria. The use of soil from old fields is more generally suc- 

 cessful. As the bacterium on sweet clover is apparently 

 the same as that on alfalfa, the inoculation of fields where 

 this plant grows freely is not often necessary, for the bacteria 

 transfer readily from one to the other. The bacterium from 

 red clover will not grow on alfalfa. When a good stand of 

 alfalfa is once obtained, it is then easy to spread the bacteria 

 to other fields by scattering a few hundred pounds of the soil 

 from the old fields over each acre of the new. The same 

 result may be obtained if manure from stock which have been 

 fed on alfalfa hay is used, while the dust blown from one 



