Increasing salinity is one of the most significant environmental problems facing the world. The issue of rising salinity has resulted in 5.7 million hectares of Australia's most productive land making it useless for agricultural purposes. The effects of rising salinity levels have the potential to ruins crops, pollute fresh water systems and kill off vegetation on a global scale. Salt is built up in Australia as a result of natural rock weathering, or the simple act of sea salt dropping via rain or wind and flowing into the water. Vast amounts of it has built up over thousands of years in the water table. The native Australian vegetation plays a critical role in maintaining the water balance in soils. Prior to European colonization the deep routed Australian plants and trees were able to reduce discharged water by intercepting rainwater. Salt-affected soils occur when there are dramatic changes in the natural water systems whenever the land. The extensive removal of deep-rooted native vegetation by Europeans and its replacement with crops and pasture has upset the water balance over large areas as the shallow roots of crops are unable to absorb the same amount of water as native trees . Rising water tables brings dissolved salts towards the surface, causing the salinization of soils. The seepage of groundwater into rivers has increased their salinity, polluting the major source of water for domestic and irrigation uses.
There are Two Types of Salinity - Dryland and Waterlogged Salinity.
Dryland salinity occurs when the land is cleared of its natural vegetation, groundwater is gradually drawn towards the surface by evaporation. This brings dissolved salts to the surface, killing trees and crops. Waterlogged salinity occurs when the water table is raised by excessive irrigation or rainfall. In addition to tree and crop loss, it can result in increased salinity in waterways. The seepage of groundwater into rivers has increased their salinity, polluting the major source of water for domestic and irrigation uses.