Salts contained in the soils are dissolved in the percolating groundwater. In areas where the watertable is close to the surface, capillary action can draw salty water to the soil surface. The ground becomes waterlogged. Also, evaporation of water from the surface concentrates salts. Many crops are intolerant of these conditions.
Saline soils occur naturally in parts of coastal, south-west and northern Queensland.
However, salinity may also be induced by land management practices. The large quantities of water transpired by trees effectively maintain a lower watertable. Tree clearing may result in a rise in groundwater levels, with salts being concentrated at the soil surface by evaporation. Irrigation may lead to salinity if water with high salt levels is used or if the excessive use of water results in a rise in the watertable. The riparian zone is the zone directly adjoining a waterway.