TIME OF SOWING 391 



among growers before they knew the explanation. The natural 

 inoculation, however, on the few plants that succeeded, was enough 

 to inoculate all the soil when it was replowed and scattered through. 



The most successful method of inoculation up to recent years 

 has been to carry soil from an old alfalfa field to the new one. 

 Two hundred to three hundred pounds of soil per acre is usually 

 sufficient. When the soil is transferred, care should be taken not to 

 allow it to become too dry, and as soon as it is spread on the land the 

 ground should be cultivated or harrowed, as exposure to bright sun 

 is injurious. An excellent way is to mix the soil with manure and 

 apply it with a manure spreader. The manure furnishes a good 

 medium for the bacteria, and often insures inoculation when it is 

 difficult to secure it otherwise. 



At present artificial culture may be purchased or secured from 

 the agricultural colleges and the United States Department of Agri- 

 culture, which is very simple to apply and generally ' successful if 

 directions are carefully observed. In a limestone region, after 

 alfalfa has been cultivated for a number of years, it is generally 

 no longer necessary to inoculate when sowing, as natural inoculation 

 spreads and seems to remain in the soil for many years. On soils 

 that are not naturally rich in lime it is advisable to inoculate when- 

 ever alfalfa is sown. 



Time of Sowing. Alfalfa may be sown any time during the 

 spring or early summer. The principal objection to this is that, 

 no crop being harvested that season, the use of the land is practically 

 lost. Also, if the land is infested with weeds, it is not possible to 

 free the land from weeds before sowing alfalfa. For these reasons 

 many farmers prefer to sow in late summer or possibly in early fall, 

 after a grain crop has been harvested. In the northern limits of 

 alfalfa culture, it should not be sown later than the first of August, 

 but southward, the season may be correspondingly later (Fig. 169). 



One of the main precautions in fall seeding is to have a very firm, 

 compact seed bed, as alfalfa will go through the first winter much 

 better on a solid seed bed than a loose one. For this reason many 

 farmers do not plow for fall seeding, but merely work up the land 

 thoroughly with the disk and cultivator. 



