Investment

Soil acidification currently affects more than 2M ha in SA and, unless liming applications are expanded and rates increased, this could increase to 4-5 Mha over the next few decades, especially given increased cropping intensity and reliance on fertiliser nitrogen in most areas. Acid soils in Victoria were estimated at around 3M ha in 2015. Subsoil acidity is more difficult to correct with lime applications because of its low solubility and movement, and this is becoming more common in the southern region, especially in Victoria. Adoption of lime applications have increased in both states, but not to levels to correct past and ongoing acidification. Furthermore, recent evidence indicates that current recommended rates of lime are insufficient to neutralise increased rates of acidification under modern crop rotations, especially subsoil acidity. This three year investment will provide the necessary resources to collect much needed long-term data from existing lime experiments across SA and southern Victoria.

The knowledge generated will:

About 16 existing lime field trials established by current investments will be monitored for an additional three seasons starting in 2022 with aim of collating at least four years of soil and crop response data following the lime treatments. New data from the field trials will be used to update extension aids and calculators developed in SA (available from acidsoilssa website) and Victoria (Federation Uni website), especially lime recommendations considering the persistence of lime benefits, the need to reapply ensuring no serious yield decline, and the impact on risk. Trial data from previous investments may also be available for integration into the data set.