Determination of salt leaching and gypsum requirements with field tests of saline-sodic soils in central Turkey

This study was conducted to determine the best method for leaching salt from saline-sodic soils in central Anatolia in Turkey. The field experiment was set up in a randomized block with three replications. As reclamation material, mined gypsum was applied to the treatment plots in 0, 20, 40 and 60 t ha⁻¹ dosages and 3.60 m leaching waters were applied to the plots. The infiltration capacities of the soil increased in proportion to the amount of gypsum applied. Leaching of 70% of the soluble salt from the soil profile required a depth of leaching water of approximately six times the soil depth to be reclaimed. Relationships between theoretically calculated and required actual gypsum could be described by exponential equations. Gypsum application showed a good response. It was concluded that gypsum or other reclamation materials have to be applied to reclaim sodic soils in the Ereğli plain.