176 Missouri Agricultural Report. 



has not been so depleted, a good stand of alfalfa may be secured 

 without manuring or fertilization. 



The third and perhaps the most important factor controlling 

 the growing of alfalfa is inoculation. By inoculation is meant 

 putting into the soil the nitrogen-gathering bacteria that live in 

 the rcots of the alfalfa plant and furnish a part of the plant food. 

 Many soils on which alfalfa has never been grown do not contain 

 these bacteria ar.d hence it is necessary to supply them before the 

 plants will thrive well. Inoculation is essential on practically all 

 upland soils in Missouri. Tiij most practical way for the farmer 

 to inoculate his land is to scatter soil from an old alfalfa field over 

 his ground before seeding. This may be applied at a rate of 300 

 pounds to 400 pounds per acre and should be harrowed in im- 

 mediately since exposure to light kills the bacteria. The bacteria 

 which soil contains multiply very rapidly and soon the new field 

 is thoroughly inoculated. If it is not practical to secure soil from 

 an old alfalfa field some taken from patches of sweet clover found 

 growing along roadsides or railways may be used. The same 

 bacteria that live on this plant live also on alfalfa. There is no 

 need of fearing to infect the land with sweet clover as this plant 

 is an annual and may be readily killed by mowing before the seed 

 has matured. Artificial culture of these bacteria are now made 

 which the farmer may secure, sprinkle over his seed and thus 

 inoculate them in this manner. This method of inoculation is 

 still in the experimental stage, however, and we have not found 

 these cultures a success in every case, so that their use is to be 

 lecommended only experimentally. Only about 25 per cent of 

 our fields on which this culture was used have shown any benefits 

 from inoculation while soil from old alfalfa fields has given results 

 on 85 per cent of the fields inoculated in this manner. This may 

 be due to the improper methods of handling, but the average 

 farmer will secure better results by using the soil rather than 

 treating the seed with this culture. 



LIME IS REQUIRED. 



Perhaps a 'fourth essential to the production of alfalfa is 

 abundant lime in the soil. In many of the eastern states an ap- 

 plication of lime is necessary to secure a good stand. However, 

 most Missouri soils, except a few that are poorly drained, have an 

 abundant supply of lime and our experiments show that only in a 

 few cases is lime necessary. It is sometimes beneficial for correct- 



