Leaching Potential of Sea Water in Saline Souls

Limited fresh water resources, inefficient irrigation and soil salinity reduce agricultural production in arid and semi-arid countries. This paper describes one of the uses of sea water to reduce salinity of an excessively saline soil in Oman. The objective of the study was to determine the efficiency of sea water to leach salt from a simulated profile of a coastal soil. The sandy soil under study contained a salt crust at the surface and was less saline in the subsurface layers. Soil was repacked in columns, 10 cm in diameter and 43 cm long, and three depths of sea water applied, Lo. 43, 64.5 and 86 cm. An additional column was leached with tap water for comparison. A leaching trial was undertaken in the field, using soil from inside cylindrical rings (D 31.5 cm) inserted into the surface. Leaching with sea water reduced soil salinity by between 90.4 and 17.8%, depending on the depth of sampling. Salinity in the surface soil layer was reduced more than in underlying layers. Most efficient leaching occurred with the application of sea water equal in amount to the depth of soil to be leached. It was concluded that sea water is an effective leaching agent, but leached soils still contained more salt than when leached with the same amount of tap water.