SWEET CLOVER: GROWING THE CROP. 29 



A comparatively new method which has given successful results 

 calls for dampening each bushel of seed and spreading it on a cloth, 

 paper, or cement floor, where half a gallon of thoroughly inoculated 

 soil from sweet-clover or alfalfa plants may be sifted over it. Some 

 people prefer to add a trace of glue or sugar to the water, so that 

 more of the soil will adhere to the seed, although some soil will remain 

 on the seed if the glue or sugar is not used. When only this quan- 

 tity of soil is used it should be collected from around the roots of 

 sweet-clover plants which are abundantly inoculated. Such soil 

 may be collected in the fall and kept until spring in a cool, dry, dark 

 place with no injury to the inoculating organisms. Seed treated in 

 this manner should be kept in the dark and should be sown as soon 

 as possible after treating. 



THE PURE-CULTURE METHOD. 



The pure-culture method has the advantage of greater ease of 

 transportation and freedom from danger of introducing harmful 

 pests upon the farm. Inoculation by pure cultures may be carried 

 out in either of two ways : 



(1) A bottle of pure culture of the proper kind of bacteria is 

 opened and the culture mixed with a convenient quantity of water; 

 this diluted culture now is mixed thoroughly with a considerable 

 quantity of soil, preferably from the field where the legume is to be 

 sown; the treated soil is then distributed in the same manner as 

 when inoculation is made by the soil-transfer method. 



(2) A pure culture of the proper kind of bacteria should be ap- 

 plied to the seeds in such a way that they will all be moistened. 

 The seed should then be permitted to dry in a shady or dark place 

 and should be planted as soon as possible after it is dry. Drying 

 may be facilitated by adding dry, sifted soil, preferably from the 

 field where the seed is to be sown. Inoculating organisms very often 

 die within a week after the seed is inoculated. It is highly desirable, 

 therefore, that the inoculation be made the day the seed is sown. 

 Inoculated seed never should be dried in the sun. 



The question is often asked whether it is advisable to inoculate 

 seed with the pure-culture method and sow it on honeycombed 

 ground in the spring. No experiments have thus far been completed 

 to determine the advisability of this procedure. Some inoculation 

 would probably result from this practice, because the bacteria on 

 that portion of the seed next to the ground would be protected from 

 the sunlight and would in a short time under ordinary conditions be 

 covered by the freezing and thawing of the soil. While it is hardly 

 possible to obtain as complete inoculation by this practice as by other 

 methods, it is to be preferred to no inoculation. 



