Catch more, store more, grow more
GroundCover™ Issue: 114 | Author: Rebecca Jennings
At a glance
What: the five-year, $17.6 million GRDC Water Use Efficiency Initiative
Who: the GRDC, CSIRO (as scientific coordinator), 16 grower groups
Where: projects across Western Australia, New South Wales, Victoria, South Australia and Tasmania
Why: lift crop and system productivity and water use efficiency by at least 10 per cent
How: crop sequences, summer fallow management, early sowing, managing constrained soils
The Water Use Efficiency Initiative – a nationwide RD&E effort to maximise a crop’s use of every millimetre of rainfall – goes to the heart of farming the world’s driest inhabited continent. The outcome has been nothing short of an agronomy revolution
It was never going to be an easy task. Seventeen separate projects, 16 grower groups, about 1000 on-farm trials spread from Western Australia to Tasmania and $17.6 million funding over five years; but the GRDC Water Use Efficiency (WUE) Initiative was never just about the numbers.
It was about building knowledge and resilient production systems.
It began as a brainstorming session about factors that prevent crops from reaching water-limited yield potential, and went on to deliver some of the most significant productivity gains to Australian grain growers yet achieved by a single program.
The initiative was one of the biggest research projects undertaken in Australian agronomy, but because of its breadth and the incremental delivery of outcomes, the full scale and story has perhaps not been fully appreciated. The WUE Initiative brought together growers, advisers, researchers and farming systems groups across all rainfall zones. It ensured that catching, storing and using rainfall effectively is now front of mind for everyone, and challenged growers to identify profit drivers and prioritise operations accordingly.
Importantly, the suite of research projects revealed that by combining pre-crop and in-crop management practices, growers can increase water productivity (crop yield per unit of water used) by more than 40 per cent, a huge jump up from the initiative’s initial target of 10 per cent.
What this means is Australian grain growers have become the most advanced in the world for sustaining crop production in the face of declining rainfall.
This on-ground impact was recognised by the science community with a prestigious Eureka Award in 2014 (the Department of Agriculture Landcare Eureka Prize for Sustainable Agriculture), which placed agronomy on par with the more ‘popular’ fields of science.
However, GRDC executive manager Stuart Kearns, who led the WUE program from 2008–13, says that while the Eureka Prize was certainly an honour, the real notch on the belt came from seeing research collaboration unfold on farms across the country.
“I think the fact that the projects were participatory in nature was the key,” Mr Kearns says. “We built on people’s strengths rather than plugging weaknesses. It was always about empowering farming systems groups to have the conversation with researchers about the things that were most important to them, to their farm businesses.
“Back in 2008, when the program was initiated, the grains industry hadn’t experienced that level of participatory research collaboration before. I think using WUE as the metric to benchmark performance lent itself to this approach because it cut across all farm systems, in all regions.”
The WUE Initiative’s ‘catch-cry’ focused on three core aspects of water use in cropping systems:
- Catch more: how can growers increase the capture of rainfall?
- Store more: how can growers increase the amount of moisture retained in the soil?
- Grow more: how can growers improve the conversion of stored soil moisture into grain?
The 16 diverse research projects targeted different innovations, organised into four themes related to the type of innovation pursued: integrating break crops, managing summer fallows, managing in-season water use, and managing variable and constrained soils. It was a simple approach that allowed participating grower groups to base local research projects on the theme – or themes – which they believed could achieve the greatest impact in their region, and then matching them with the scientific expertise to rigorously test the ideas.
For example, high-rainfall-zone growers set out to improve soil to avoid waterlogged crops, while in other areas such as central-west NSW, growers looked at strategies to capture and store summer rainfall more effectively.
It was a successful formula, if the numbers are anything to go by.
At the end of the five-year WUE Initiative:
- participating growers have increased returns by, on average, $250 per hectare;
- on some farms, weed control and maintaining ground cover over summer increased yield by 60 per cent and earlier sowing of slow-maturing grain added another 22 per cent;
- sowing a legume break crop was shown to be able to increase yield by up to 83 per cent; and
- implementing WUE management practices contributed to a 25 per cent increase in average winter yield across all regions.
The WUE program also had a social impact.
“Farming is an isolated industry, but we had growers across the country working on the same issue, and they could discuss their experiences and learn from one another at the initiative’s annual forum,” Mr Kearns says. “There were also professional development benefits for the farming systems groups, who developed relationships with their counterparts in other regions and who have built lasting networks they can draw on for future research projects.”
Dr John Kirkegaard, senior principal research scientist with CSIRO Plant Industry, who along with CSIRO Agriculture Flagship research team leader Dr James Hunt led the science, agrees capacity building was important.
“One challenge we faced was benchmarking because each farming systems group had a different set of data for growers in their region,” Dr Kirkegaard says. “Our goal was to develop a consistent benchmarking system and, as a result, growers now have the tools and ability to collect data for long-term benchmarking. I believe the key legacy of this initiative is better-informed grower groups.”
Another challenge was changing commonly held perceptions about farm management practices.
The initiative tested and proved an early hypothesis presented by Dr Kirkegaard and Dr Hunt, which viewed weed control as a bigger influence on WUE than stubble.
“Stubble retention is important, but we believed if growers really want to improve their WUE then they should control the weeds that steal water and nitrogen that would otherwise be stored at depth in the soil, out of reach of evaporation,” Dr Hunt says.
He saw once-sceptical growers reduce crop residue to threshold levels, where it can protect the soil from erosion but still allow machinery to pass through, and turn their attention to more timely summer weed control.
It emphasised that improved pre-crop management is often more important than in-crop management to lift WUE and yield in wheat-cropping systems – although both are clearly required.
Dr Hunt says the WUE Initiative was unique in that it did not try to introduce new management practices, but rather looked at how different activities, in combination, could impact on productivity using a systems approach, rather than a paddock-by-paddock or crop-by-crop basis.
“Weed control, nitrogen application, variable management – these are on-farm activities the industry has known about for many years, but for the first time we were able to put numbers around the impact of each practice in a local context,” he said. “Growers could then see how using each of the four themes in combination – rather than isolation – delivered the greatest impact.”
Importantly, rather than requiring significant investment or practice change, it showed how growers can achieve significant results by identifying profit drivers and prioritising operations accordingly – such as focusing on timely summer weed control.
So, how is the WUE research changing the grains industry? Feedback from grower groups reveals there has been substantial on-farm practice change to influence WUE.
The area of non-cereal break crops has increased dramatically. Growers in the southern Mallee of Victoria increased break crops from 11 per cent of cropped area in 2008 to 38 per cent in 2012.
More early-sown, slow-maturing varieties are also being planted, with much of the landscape of southern NSW sown early in 2014.
At an industry level, Dr Kirkegaard says plant breeders are incorporating the research as they develop new varieties, while internationally, the initiative has inspired a similar approach to participatory research in dry environments such as North Africa.
The initiative has even influenced how GRDC grower practice surveys are worded, and the GRDC is drawing on the lessons learned to roll out future programs, such as the Frost Initiative.Check out the results of the GRDC WUE Initiative in the Ground Cover Supplement Water Use Efficiency, available at: www.grdc.com.au/GCS82
The GRDC WUE Initiative developed a benchmarking system, available at: www.csiro.au
GRDC Project Code CSP00146
Region South, West, North