132 THE FORAGE AND FIBER CROPS IN AMERICA 



their vitality for a considerable time. It was found, however, 

 that when the organisms were dried slowly under the usual 

 atmospheric conditions, as was done in commercial practise, the 

 organisms were killed. 1 



3. To apply soil from a field that has produced abundantly 

 tubercle-bearing plants of the species it is desired to grow. 

 This is a successful method of inoculation. Soil at the rate of 

 100 or more pounds to the acre is spread upon the field after 

 it is plowed and within a few days of planting. It is immediately 

 harrowed into the soil in order not to subject the organisms 

 to sunlight and air-drying. The soil should be obtained from 

 the field in as fresh condition as possible. While being held 

 for use it should be kept out of the sunlight and where it will 

 not dry out. While this method has given excellent and fairly 

 uniform results, so far as inoculation is concerned, it is rather 

 expensive where soil is shipped long distances, and has the 

 added disadvantage of possibly introducing weeds, fungous 

 diseases and insect enemies. The New Jersey Station has 

 obtained good results by passing water through an inoculated 

 soil and sprinkling the water upon the land it is desired 

 to inoculate. 



140. Nitrifying and Denitrifying Organisms. The sources 

 of organic nitrogen in the soil are : ( i ) the nitrogen compounds 



1 The Department of Agriculture at Washington is now experimenting with 

 a method of distributing liquid cultures in glass tubes, thus obviating the 

 drying and consequent destruction of the organisms. 



The liquid cultures are forwarded in hermetically sealed tubes accompanied 

 by detailed instructions for multiplying and applying the bacteria. In one gallon 

 of clean, boiled, and cooled water dissolve three teaspoonfuls of sugar and the 

 contents of package No. 1 (which consists of 72 grains of potassium phosphate, 

 monobasic, and three grains of magnesium sulphate). Add the cultures, package 

 No. 2, and keep in a warm place. After 24 hours add package No. 3 (which 

 contains 0.6 ounce of ammonium phosphate) and allow to stand for another 

 24 hours, when the liquid should be cloudy on account of the myriads of 

 bacteria it contains. It is now ready for use. Moisten the seed with this 

 liquid; dry, and sow as quickly as practicable. If preferred, the liquid may 

 be sprinkled on a portion of soil and this scattered over the land. 



