Effects of Gypsum Particle Size on Reclaiming Saline-Sodic Soils in Egypt

In Egypt, improving salt-affected soils is important for ensuring secure agricultural productivity. Gypsum is commonly used for the reclamation of saline-sodic and sodic soils. Soil column experiments were conducted to investigate the effect of gypsum, ground to varying degrees of fineness, on the reclamation of clayey saline-sodic soils. The soil used was obtained from Gelbana Village in the Sahl El-Tina Plain, Sinai Governorate, Egypt. Three different degrees of gypsum fineness (<0.5, 0.5–1, and 1.0–2.0 mm) were tested, and the following treatments were included: control (leaching with no gypsum addition), fine particles (<0.5 mm), medium particles (0.5–1.0 mm), and coarse particles (1.0–2.0 mm). The gypsum requirement (GR) to reduce the initial ESP from 29.8 to 10 percent was calculated for the 30-cm soil matrix. The application of gypsum and the subsequent leaching enhanced the reclamation and decreased the salinity as well as the sodicity. With greater fineness of the gypsum particles, a greater decrease in salinity as well as sodicity was obtained. This study suggests that, for greater reclamation efficiency, the gypsum used in the reclamation of saline-sodic soils should be of fine particle size.