• Effect of sulfuric acid on water movement in calcareous soils.

      Yahia, Taher Ahmed, 1947-; Warrick, Arthur W. (The University of Arizona., 1974)
      Water penetration into calcareous soils was measured in soil columns after concentrated sulfuric acid was applied on the soil surfaces at rates of 1 to 20 metric tons/ha. Water penetration reached a maximum with increasing rates of acid application before decreasing at the highest rates. The increase in water penetration by the acid treatments was pronounced, particularly in sodium-saturated soils where the depth of water penetration at 5 hours was as much as 8 times that with distilled water. Surface applied sulfuric acid was more effective than chemically equivalent amounts of surface applied gypsum in increasing water penetration into sodium-saturated soils. When the acid was applied as a band on the soil surfaces, the wetting fronts were semi-circular. The time required for leaching and the changes in exchangeable sodium and the total dissolved salts were measured in a separate experiment. The addition of acid increased soluble salts but reduced the exchangeable sodium and the time required for leaching. The reduction in exchangeable sodium percentage was much less than that estimated by the conventional methods. Sulfuric acid, which may become abundant through industrial by-product recovery, could be used as an aid for increasing water penetration on sodium-affected calcareous range land as well as on irrigated soils.