The Bulletin. 7 



new and uninfected field to largely uiiliL it, not only for the purpose 

 for which it is being put in order, but also for the growth of a large 

 number of other crops. These facts emphasize the necessity for 

 great caution in transporting and using soil for inoculating purposes 

 from unknown parties and fields. 



When soil is used, it will be well, if possible, to collect it during 

 cloudy weather and apply it broadcast over the prepared field on a 

 cloudy day, and preferably immediately preceding a rain, so that the 

 bacteria contained in it will be washed into the soil which it is de- 

 sired to inoculate. If for any reason there intervenes any great length 

 of time between the taking of the soil from the infected field to the 

 applying of it on the field that is to be sown to alfalfa, the soil should 

 be stored in some cool, dark room to prevent its drying out, for too 

 much drying and direct sunshine on the inoculating soil will prove 

 fatal to the beneficial bacteria which it contains. Notwithstanding 

 the drawbacks attending the use of this method of inoculation, it has 

 been found during the past four or five years in work along this line 

 being conducted on the Test Farms of the State Department of Agri- 

 culture with alfalfa, bur clover, and hairy vetch, that this is one of the 

 most successful and practical methods thus far tried. It is rather an 

 expensive method, however, especially if the inoculating soil has to 

 be brought from any great distance ; but taking everything into con- 

 sideration, the expenses incurred by this method will be justified gen- 

 erally by the success resulting from its use. 

 • By Water-extract from an Infected Soil. — With this method, gen- 

 erally from 50 to 100 pounds or more of soil, from some field on 

 which either alfalfa, bur clover or sweet clover has grown well with 

 the formation of a large number of nodules on the roots, are placed 

 in some vessel and enough water added to more than cover it. The 

 whole is then thoroughly stirred with a stick or paddle in order to 

 bring the water into intimate contact with all portions of tlie soil, 

 after which the mixture should be allowed to stand and settle for a 

 short while. 



The seed to be sown should be soaked in the water that stands 

 above the soil only a sufficient length of time to be assured of their 

 becoming thoroughly wet. This may be done by placing the seed in 

 a coarse bag and dipping them in the water for a few minutes,- or by 

 pouring off sufficient of the water from the soil into a separate vessel 

 into which the seed had previously been placed and allowing to stand, 

 after the seed have been stirred, only for a short time. In either case, 

 the seed should be removed from the Avater and spread out in a thin 

 layer in some cool, shady place where the air is stirring and be 

 allowed to dry out. It will be well for the seed to be exposed as 

 little as possible to direct sunlight after this treatment, and to go into 

 the ground pretty soon after the inoculation. - 



This method of inoculation is generally resorted to when the 

 quantity of inoculating soil is relatively scarce for any reason ; and, 



