TREND Primary Production scientists are working with South Australian farmers to prepare for future climate uncertainty. Working with landholders, we are assessing the vulnerabilities of current crops and farming techniques to test their sustainability, as well as developing new options to enable our agricultural regions to remain productive. Our first step is to validate the techniques used to predict on-farm conditions under future climate scenarios. To do this, we look at areas which are experiencing the conditions predicted to affect other growing regions in the future (using a “spatial analogue”). We also examine historical records to see what has happened in the past when a farm experienced a run of unusually extreme conditions (like a drought) that are similar to those projected in the future (using a “temporal analogue”).
Using sophisticated simulation software to study the yields of wheat crops, TREND scientists found both of these methods useful but with different advantages and disadvantages. 
Benefits of the temporal approach include the consistency of on-farm conditions such as soil and farming system, however it is very dependent on the particular run of seasons. The spatial approach allows comparison of farming systems but must be used carefully as other factors (such as soil type) can be important. A limitation of both approaches is that no current or past scenario exists that includes the elevated levels of carbon dioxide in the atmosphere projected in the future. However, our simulations do suggest the increase in carbon dioxide, which plants use to photosynthesise, may partially offset growth rates slowed by a drier climate.
This research was presented at the 15th Australian Society of Agronomy Conference, held in Lincoln, New Zealand, in 2010. The scientific paper underpinning this article can be downloaded here: