The effect of leaching with different condition on effluent quality removed from calcareous saline soil columns

Soil salinity is one of the most important factor which causing a considerable decrease in crop productivity of pistachio orchards in Kerman. In this research, the effects of applying different amendments on reclamation of a saline calcareous soil was investigated by using experimental soil columns. Treatments included: a) irrigation water, b) irrigation water gypsum mixed with soil surface, and c) dissolved gypsum as well as d) sulfuric acid application. Leaching was done intermittently and 2 pore volumes (PVs) were allowed to pass through the soil columns. Based on the results, no significant difference was observed in the concentration of cations as well as EC among different treatments. Application of 1.5 PVs of irrigation water, removed 60% of the total sodium, 70% of magnesium and 70% of soluble salts from the soil column. The cumulative leached Ca2 caused by 2 PVs was very small, accounted for about 4 percentage of total content of Ca2. Application of chemical amendments was not significant on infiltration rate as compared to irrigation water. In terms of water requirement for salt removal from 1 to 1.5 pore volumes, it is recommended that 1 pore volume of irrigation water which efficiently reduced soil sodium and magnesium concentration, soil EC and costs, is the suitable strategy for practical reclamation of the studied soil.