Salinity affects plant growth and water quality, resulting in lower crop yields and reduced agricultural production.
As soil salinity increases, most plants find it increasingly difficult to extract water from the soil. Increased levels of salt can disturb the balance of plant nutrients in the soil and some salts are toxic to certain plants. Although there is a wide range of salt tolerance in plants, most normal crop and pasture plants are not highly salt-tolerant and will eventually die out under saline conditions.
The implications of river salinity may also be costly for high value enterprises such as irrigated and horticultural crops. The yields of some particularly sensitive plants, such as carrots, beans, avocados and strawberries are affected by saline water at levels as low as 700 EC.
Salinity may also affect the physical and chemical properties of soil, resulting in surface soil compaction and erosion. High levels of salt can dehydrate soil bacteria and fungi and reduce soil health, which is depended on good microbial activity for the formation of organic matter and nutrient recycling. The breakdown in soil structure, together with the associated loss of plant cover, results in a greater exposure of the soil to erosion. Sheet, rill, gully and wind erosion is commonly caused by salinity.
Salinity affects production in saline discharge areas, where the direct impacts of salinity are experienced. There can also be an impact on the farm business if salinity management needs to be undertaken around a recharge site. In extreme cases, badly affected land may need to be removed from agricultural production if management options to improve salinity have been unsuccessful or are not economic.
In addition to reduced agricultural production, there are also costs associated with protecting land from further degradation, remediating salt scalds, groundwater monitoring, fencing, revegetation and repairing damage to farm infrastructure such as pipes, roads, buildings and dams.
The booklet Productive use of saline land and water contains information about the management and productive use of land and water affected by salinity.
Page last updated: 26 February 2011