Reactions of urea phosphate in calcareous and alkaline soils: II. effects on soil sodium and salinity

Abstract

Abstract Large areas of agricultural land, containing alkalinity and salinity problems, are potentially suitable for crop production with little alteration of their chemical properties. This study was conducted to determine and compare the effectiveness of urea phosphate (UP) in reducing soil salinity and alkalinity with sulfur foam (SF), phosphoric solution (PHP), and a mixture of SF and UP (Mix) on leaching soil sodium (Na) and salinity on two saline sodic soils (Pima L and Crot CL) in columns. Each of these amendments was applied at rates of one and two equivalent amounts of the exchangeable sodium (Naex). Urea phosphate was as effective as PHP or Mix treatments in reducing soil salinity and alkalinity in Pima and Crot soils. No difference was found between rates of application (1 and 2 equivalent amount of Naex) except for soil pH. The decrease in soil salinity was similar to the decrease in pH levels; both decreases followed this order: PHP, UP, Mix, SF, and control treatments. No significant differe...