Seed Inoculation of Lucerne ( Medicago Sativa ) and its Relation to the Motility of the Nodule Organism in Soil

THE successful results that are being obtained in other countries from the inoculation of lucerne seed with the nodule organism (Bacillus radicicola, Beyerinck) have stimulated investigation of this subject in England. In this practice the details of the method used in the inoculation are of great importance. The method consists essentially in making a suspension of the bacterial culture in some liquid, and in using this suspension to wet the seed. In this way each seed is coated with a film of liquid in which the bacteria lie. There is evidence that after penetrating the tissues of the root the bacteria are unable to pass for any significant distance along it. Consequently, when the seed has germinated, the bacteria must progress or be carried through the soil in order to reach from the seed-coat to the various parts of the root system, where nodules are to be formed. A study of the factors affecting the motility of the organism and its passage through soil has, therefore, an important bearing on the technique of seed inoculation.