CHEMICAL STUDIES ON APPALACHIAN UPLAND PODSOL SOILS: II. ORGANIC MATTER-ACIDITY RELATIONS

Abstract

When leached with distilled water, the raw humus of the A1 horizon of Quebec virgin podsols gave percolates of gradually increasing pH values over periods of 14 weeks, beginning in two instances at 4.3 and rising to 5.4, and in a third at 3.8, rising to 4.8. When concentrated by evaporation to from one-tenth to one-twentieth of the original volume the percolates retained 83.5 to 99% of their total acidity. The concentrates were fractionated by dialysis through cellophane. From 46 to 91% of the acidity dialyzed. In the dialyzates from five soils, 47.5 to 56.4% of whose acidity dialyzed, total sulphuric acid was found in amounts varying from 30 to 52% of the total acidity. The free (alcohol-soluble) sulphuric acid amounted to 9.5 to 23% of the total acidity of the percolate. Phosphoric acid was present in mere traces in some samples, but in one instance the total phosphoric acid content was sufficient to account for 28% of the total acidity, if it was present in the free state.