Crop simulation modelling has revealed that dry seeding up to half of a 3000 hectare wheat program in a low rainfall area of Western Australia can deliver consistent yield benefits and significant increases in profits over time.
But researchers have warned that, despite the findings, growers need to be aware of the risks of dry seeding including crop failure, inadequate weed control and wind erosion.
The research was funded by the Department of Agriculture, Fisheries and Forestry (DAFF) and Grains Research and Development Corporation (GRDC) under the project ‘Developing climate change resilient cropping and mixed cropping/grazing businesses in Australia’.
CSIRO researcher Michael Robertson will present the results at this month’s 2011 Agribusiness Crop Updates, coordinated by the Grains Industry Association of Western Australia (GIWA) on behalf of the WA Department of Agriculture and Food (DAFWA) and the GRDC.
Dr Robertson said the research found that dry seeding up to 50 per cent of a 3000ha wheat program at Mullewa produced average farm wheat yields 0.1 to 0.3 tonnes per hectare better than those achieved from waiting to seed in wet conditions, in 80 per cent of seasons.
Yield results were achieved by applying the Agricultural Production Systems Simulator (APSIM) to actual rainfall data for Mullewa from 1971 to 2010.
“These results illustrate that earlier sowing dates through dry seeding of cereals generally results in higher yields, in the absence of frost,” Dr Robertson said.
“When applied to actual farms, the results would vary according to factors including seeding capacity and soil erosion risk, but I am confident the principles of the results would remain the same.”
Dr Robertson said the crop simulation modelling work had not yet been applied to other rainfall zones in WA, but he expected similar results.
“So far we have only looked at low rainfall situations because that is where growers are dry seeding a lot, but we plan to extend the research into the medium and high rainfall zones.”
Dr Robertson said the research had been conducted to help quantify the yield effects of dry seeding cereals, which was increasing in WA.
More growers were dry seeding cereals because opening rains were occurring later and with more variability.
“While it has long been common practice to dry sow lupins and canola before the seasonal break, dry seeding of cereals has only recently gained prominence in the Wheatbelt,” Dr Robertson said.
“Growers are not completely confident if they are doing the right thing.”
Dr Robertson said growers considering dry seeding should:
- Have a robust integrated weed management plan in place to ensure they were seeding into clean paddocks.
- Carefully select paddocks and crop types carefully – choose those you would still choose to seed into even in a very late break.
- Keep input costs low, particularly for fertiliser, to reduce break-even yields.
The dry seeding research was conducted in WA by CSIRO, the Department of Agriculture and Food Western Australia (DAFWA) and Planfarm.
DIAGRAM: This diagram illustrates how opening rains at Mullewa have become more variable in recent years. The blue bars show the period of time over which the first 10 days of wet seeding (representing the ‘break of the season’) occurred from 1957 to 2010. In the last 10 to 15 years the break of the season has happened later, and there have been some years where it has taken a long time to accumulate 10 days of wet seeding.
GRDC Project Code: LIE00007
GRDC Project Code
West, National, North, South