Effect of Surface Applied Sulfuric Acid on Water Penetration into Dry Calcareous and Sodic Soils

Abstract

AbstractSulfuric acid, a surplus by‐product of copper smelters in the Southwest, was studied to determine a possible role in reclamation and revegetation of calcareous and sodic range soils. The rate of water penetration into dry calcareous soils was measured in columns as well as boxes after concentrated (93%) sulfuric acid was applied to the soil surfaces. The rate of penetration increased with increasing acid application rates, but then decreased, with optimum application rates ranging from 5 to 15 metric tons/ha. Acid was especially effective in increasing the rate of penetration into sodium‐affected calcareous soils. When acid was applied as a band on the soil surface, the wetting front advanced in an elongated semicircular form with depth. Surface applied acid was more effective than surface applied gypsum in increasing water penetration into sodiumsaturated soils. Sulfuric acid may be useful for increasing water penetration into and subsequently aiding in revegetation of sodium‐affected soils of semi‐arid regions.