Track 2-09: Soil Quality, Biology and Plant-Soil Interactions
Description
The Upper South East of South Australia has been identified as being at risk of extensive soil degradation, with large areas already affected by dryland salinity and waterlogging. To mitigate this, an extensive network of drains has been installed. In 2009, 19 soil surveys were conducted on land adjacent to a number of deep drains (> 1.0 m) in order to determine soil salinity and pH. The surveys indicated low levels of topsoil salinity (0-10 cm) in the southern part of the region, while 66% of soil sampling sites in the northern zone had salinity levels (ECe) below 4 dS/m. These results suggest that important changes in soil salinity have occurred, which are likely to impact on pasture species adaptation. To identify suitable pasture options for these drained areas, four pasture evaluation trials were established in 2009. These trials were established on four different soil types, with each sown to 32 species including annual and perennial legumes, annual and perennial grasses and perennial herbs. Results show that an array of productive pasture species could potentially be suited to these environments, with species performance often site specific. This contrasts to the limited range of previously sown saltland species, principally puccinellia (Puccinellia ciliata) and tall wheat grass (Thinopyrum ponticum). The results demonstrate that pasture productivity can be substantially improved by the resowing of new pasture species in these areas.
Included in
Increasing Pasture Production on Drained Saltland
The Upper South East of South Australia has been identified as being at risk of extensive soil degradation, with large areas already affected by dryland salinity and waterlogging. To mitigate this, an extensive network of drains has been installed. In 2009, 19 soil surveys were conducted on land adjacent to a number of deep drains (> 1.0 m) in order to determine soil salinity and pH. The surveys indicated low levels of topsoil salinity (0-10 cm) in the southern part of the region, while 66% of soil sampling sites in the northern zone had salinity levels (ECe) below 4 dS/m. These results suggest that important changes in soil salinity have occurred, which are likely to impact on pasture species adaptation. To identify suitable pasture options for these drained areas, four pasture evaluation trials were established in 2009. These trials were established on four different soil types, with each sown to 32 species including annual and perennial legumes, annual and perennial grasses and perennial herbs. Results show that an array of productive pasture species could potentially be suited to these environments, with species performance often site specific. This contrasts to the limited range of previously sown saltland species, principally puccinellia (Puccinellia ciliata) and tall wheat grass (Thinopyrum ponticum). The results demonstrate that pasture productivity can be substantially improved by the resowing of new pasture species in these areas.
