Risk management in driver's seat
GroundCover™ Issue: 34
The wind was demonstrating just what it could do with light soils while the temperature, in the 40s, had brought wheat harvesting to a standstill when Ground Cover visited the Eyre Peninsula before Christmas.
Our mission: to get better acquainted with the Eyre Peninsula Farming Systems program. The inhospitable weather on that first day provided a good start for considering the farming challenges on this low-rainfall, marginal country where the main crop is export wheat.
On the far west coast of the Peninsula only two years in five are likely to yield an average to above-average economic outcome, according to farming systems coordinator Samantha Doudle. The trend varies across the Peninsula with central and eastern districts less volatile.
Now, at 100 mostly on-farm trial sites across lower-rainfall parts of the Peninsula, farmers are working to turn the odds in their favour. The trials are a joint effort with scientists and field officers from the South Australian Research and Development Institute (SARDI) and from other science organisations. The base is the Minnipa Agricultural Centre, which has served area farmers since 1915.
These days the theme is about risk management and farming strategically within the limits of the local environment. That sometimes means changing traditional views.
Direct drill seeding, for instance, which promises erosion control and soil benefits, is still viewed with caution by many. Says Samantha Doudle, "no-till constitutes a big change. It requires much more sophisticated management, every aspect has to be right".
Rotational long-term trials may help to allay concerns, with data showing there are yield advantages in most instances and other benefits associated with direct drill (see box this page). The advantage of collaborative research within a farming systems framework is even clearer: "a demonstration on your farm is the ultimate proof," says Ms Doudle.
The farming systems program gets those demonstrations underway by providing gear or doing the agronomic work — farmers, with the best of intentions, often don't have the manpower to spare for setting up research.
Integrating some of the many programs vying for attention is another advantage. Landcare is a good example.
"This is big country. The paddocks are huge and so is the machinery. In the past, planting windbreaks has proven a drop in the bucket," says Ms Doudle. "It's so much easier to talk about Landcare issues through the farming systems program — mostly the subject is erosion and weeds."
Peter Kuhlmann, a member of Eyre Peninsula Farming Systems management committee, and a member of the local soil board, puts it this way: "you can steer a lot of different projects from local levels and get a quick response".
Soils dictate terms
Topping the list of environmental challenges are tricky soils and inhospitable subsoils, salinity of various forms and wind erosion. Add to that, summer dry spells that dictate early crop establishment and good water-use efficiency, and you have a situation all too familiar for Australian dryland cropping.
Soils on the Peninsula are related to the marine environment and deposits. In the western district they feature grey calcareous sandy soils — a product of limestone with 20-90 per cent calcium carbonate. These soils can be associated with severe dryness-induced boron toxicity and 'magnesia patch' salinity.
Around Minnipa the soils are moderately calcareous, red sandy soils associated with moderate boron toxicity, water repellence, sodicity, wind erosion, and watertable-related salinity.
Other soils in the farming systems catchment are red-brown sandy loams and duplex soils in the east.
Looking for productive solutions
Productive solutions being trialed include the promising new fluid fertiliser approach to phosphorus nutrition, boron-tolerant barley varieties, best-bet rotations with pastures and pulses, summer cropping to increase water-use efficiency (VVTJE) and farming to soil type experiments. See separate stories next page.
Region North, South, West