Salinity in Australia
From Wikipedia, the free encyclopedia
Soil salinity is a major environmental issue in Australia. It is a problem in most states, but especially in the south-west of Western Australia.
Some of the salts originate from marine sediments, but most have been deposited in rainfall over thousands of years. Where topographic and climatic conditions are right, the salts have accumulated to high levels. Prior to English settlement in 1788, groundwater levels were in equilibrium. After clearing of the native vegetation for European-style agriculture, excess water leached down into the saline layers of soil, and allowed them to move, sometime into waterways or to the soil surface.
Over time this process caused the thin top-soil layers to become irreversibly salty, and no longer suited for agriculture. The area of salt-affected soils in 2002 was around 20,000 square kilometres. Where the land is not yet affected by salinity, it is sometimes possible for farmers to reduce the speed at which land becomes saline by re-establishing perennial plants, including perennial pastures, shrubs and trees. Where the land is already affected by salt, a number of salt-tolerant species such as Atriplex amnicola, are used to support livestock. Alternatively, many farmers in Western Australia and parts of South Australia are attempting to return salt-affect land to traditional agricultural production by digging deep-open drains.
A number of organisations are seeking ways to reduce the impact of salinity on Australian agriculture, including the Cooperative Research Centre for Plant-Based Management of Dryland Salinity.
