Field studies of water and salt movement in an irrigated swelling clay soil. III. Salt movement during ponding

Abstract

The effect of gypsum, incorporated into the plough layer of a saline, sodic, clay profile, on the leaching of salt, was determined from both in situ measurements, and from chloride determinations using samples taken before and after ponding. Observed differences in leaching patterns are attributed to water in the treated profile moving through interpedal macropores as well as through micropores within the peds (or matrix), but only through micropores in the untreated profile. The efficiency of the two mechanisms is discussed.