Salt absorption in gypsum amended acid soils

摘要: Simultaneous retention of cation and anion in equivalent amounts with no net release ions into solution, a process referred to as “Salt Absorption”, has been reported for kaolin group minerals. The objective this study was examine the extent salt absorption gypsum-amended acid soils from Southeastern United States. Surface application large quantities gypsum (5–10 Mg ha−1) shown alleviate subsoil acidity. Soil samples (0.6–0.8 m depth) representative cultivated virgin (woodland) sites kaolinitic-Cecil Wedowee (Typic Hapludults) smectitic-Bladen Albaqult) series were incubated varying additions reagent-grade CaSO4.2H2O (gypsum) or phosphogypsum (PG) solutions (2g PG L−1), which resulted Ca2+ SO 4 2− ranging 0.48–1.50 0.51–1.59 cmolc kg−1 soil respectively. composition displaced following h equilibration, showed evidence precipitation CaSO4. More than 94 89% applied, respectively, sorbed all soils. simultaneous sorption cations anions solution these amended demonstrates absorption.