Cursed By Too Much Water In A Dry Place: Implications Of Dryland Salinity For Farm Management, Policy And Reseach In Australia
Dryland salinity is one of the most prominent and intractable problems facing farm managers in the extensive non-irrigated farming systems of southern Australia. The issue was ignored by policy makers until late in the twentieth century, but is now the sole or partial subject of government programs with budgets totaling several billion Australian dollars. Salt occurs naturally at high levels in the subsoils of most Australian agricultural land. As a result of clearing native vegetation, groundwater tables have risen, mobilising the salt and causing adverse impacts to farmland, infrastructure, water resources, and biodiversity. The main action required to prevent groundwater tables from rising is establishment of perennial plants, either herbaceous (pastures or
crops) or woody (trees and shrubs). Recent technical and economic research has emphasised how difficult it will be to establish sufficient perennials to get control of groundwater tables. Where watertables are already shallow, the options for farmers are salttolerant plants (e.g. saltbush for grazing) or engineering (e.g. deep open drains). The existing options for farm-level salinity management are reviewed. There are also a number of good prospects for development of new and better options for plantbased management of salinity, and these are described. Past and current policy programs are described, and a number of changes to future policy programs are proposed to better meet the needs of farmers suffering the impacts of dryland salinity.