Note 77 — Chapter VIII · ABSORPTION BY SOILS.

That mineral fertilizers have a decided influence on the granulation of soils and the properties dependent thereon, and that this is of practical importance, is gradually coming to be recognized; see, for instance, Ein Beitrag zur Kenntnis der Wirkung künstlicher Dünger auf die Durchlässigkeit des Bodens für Wasser, von Edwin Blanck, Landw. Jahrb., 38, 863-869, (1909), and the literature there cited. Dr. R. O. E. Davis in a yet unpublished investigation has shown that the addition of soluble salts produces decided effects upon the soil-moisture relations which affect crop production. The critical moisture content is displaced, the penetrability, permeability, specific volume, vapor tension, etc., are affected in measurable degree, and it appears that the physical functions of mineral fertilizers are much greater in amount and importance than has been popularly assumed.