Soil salinity (due to ingress of excess amounts of dissolved salts in soil pores) and soil sodicity (due to excess amounts of sodium ions attached to the clay surface) are significant forms of land degradation in many parts of the world in particular in arid and semi arid regions. In Australia, soil salinity has long been identified as the major form of land degradation and the greatest environmental threat. Saline soils cover almost 6% of Australia’s land mass and impose severe threats on agricultural productivity and built infrastructure with an estimated annual loss of $250 million. In recent years, ‘soil sodicity’ is recognised as a far more significant form of land degradation and a severe environmental problem both in terms of affected land area and impact on the environment than is salinity as a problem in Australia. One third of Australian land mass is occupied by sodic soils costing an estimated $2 billion each year in lost production alone, with further significant impacts on the economy due to extensive damage to infrastructure facilities and the environment. [...] / Doctor of Philosophy

Soil salinity (due to ingress of excess amounts of dissolved salts in soil pores) and soil sodicity (due to excess amounts of sodium ions attached to the clay surface) are significant forms of land degradation in many parts of the world in particular in arid and semi arid regions. In Australia, soil salinity has long been identified as the major form of land degradation and the greatest environmental threat. Saline soils cover almost 6% of Australia’s land mass and impose severe threats on agricultural productivity and built infrastructure with an estimated annual loss of $250 million. In recent years, ‘soil sodicity’ is recognised as a far more significant form of land degradation and a severe environmental problem both in terms of affected land area and impact on the environment than is salinity as a problem in Australia. One third of Australian land mass is occupied by sodic soils costing an estimated $2 billion each year in lost production alone, with further significant impacts on the economy due to extensive damage to infrastructure facilities and the environment. [...] / Doctor of Philosophy