ABSTRACT
This chapter outlines the conceptual basis for using acids and acidulants on sodic or alkali soils and water and provides some guidelines for their usage. Application of acids, acidic gases, or aciduiants is a way to minimize soil structural degradation and associated reductions in water infiltration. It reviews and examines these unique characteristics of acids and aciduiants as amendments for reclaiming sodic soils. In some cases, acids or aciduiants may be applied for a dual purpose of lowering exchangeable sodium percentage and improving nutrient availability in Na-affected calcareous soils. The quantities of acids or aciduiants required to improve availability of certain micronutrients and phosphorus are usually determined empirically. In most calcareous soils, large quantities of acids or aciduiants are required if one attempts to dissolve CaCO3 from the entire root zone.
