Effect of some methods of saline- sodic soil reclamation on depth distribution of soluble cations

Soil salinity and sodicity are escalating problems worldwide، especially in arid and semi-arid regions. This study investigates the effect of some mineral and organic amendments on reclaiming a saline- sodic soil based on distribution of soluble cations. The soil amendments consist of control، cattle manure، pistachio residue، gypsum، manure + gypsum and pistachio residue + gypsum; water treatments with and without sulfuric acid with three replicates were performed. At the end of experiments soluble cations were measured at different depths. The results indicated that monovalent cations and also the EC and SAR showed the lowest values near the soil surface، while bivalent cations had no significant variation with depth. This finding shows that monovalent cations would be more mobile than the bivalents. Also، it was found that in comparison with gypsum، sulfuric acid had more efficiency in the SAR decreasing. However، in calcareous soils، this aim would be achieved by only irrigation. Pistachio residue and cattle manure had the highest and the lost efficiencies in decreasing of the EC and SAR. The findings of this research reveal the relative importance and efficiency of pistachio residue in reclaiming of the sodium affected soil.