High rainfall cropping

Dr Penny Riffkin, Senior Research Agronomist

Drier years and new technology has seen major expansion of cropping in higher rainfall areas of Victoria, but research suggests results could be 25 to 50% better.

Department of Primary Industries scientists are combining history and the latest breeding material from around the world to unlock the secrets to growing crops in high rainfall areas.

Cropping in the high rainfall zone is increasing due to drier climates and climate change. However, the yields that we're achieving in the high rainfall zone are still well below what we believe is the potential.

The Department of Primary Industries is investing in cropping research in this area so that returns to growers may be improved and also the future food demands can be met.

The high rainfall area is quite different from traditional cropping areas in the rest of Australia.

We have a much longer growing season and this provides a lot more options for growers. They are able to sow in autumn or in spring — they have the option of grazing crops, so this provides a lot more complexity for making management decisions.

Also, because this is a relatively new area we don't have the germ plasm or the type of cultivars which are well adapted to this area.

So we believe we can get quite significant gains by identifying what germ plasm might be better suited to this area.

We're not starting from the ground when we're looking at improving crops in the high rainfall zone.

Although this is a new cropping area, there is a lot known from research in other regions, hundreds of years of breeding and management, and we believe we can use this and we can apply this knowledge to increasing the yields in the high rainfall zone.

We've developed a crop design tool, which is designed to identify the environment in the high rainfall zone, what sort of resources we have in the high rainfall zone, how much rain, how much radiation that the crop can be used to produce grain and then looking at how to distribute that dry matter that's produced by the crops to make the most efficient crop that we can, as well as avoiding all the other risks that might be in the high rainfall zone, such as frost.

We are using crop models and historical climate data, along with site-specific information, particularly specific to the high rainfall zone that we can look at the probability of growers achieving certain yields under different management practices.

We're also looking at taking technology from overseas. We're looking at some new canola varieties that are grown specifically in Europe — they're not commercially available in Australia.

We've done some testing of those in the high rainfall zone already and we're finding that these are having around about a 20% yield increase. So we're looking at further testing those over a wider area, looking at more cultivars to see if we can get significant gains through the importation of new varieties, but also by trying to identify what characteristics it is in those varieties that may actually make a better adapted cultivar for this environment.