THERE should be a book written about dryland farming in WA.
As I say to many farmers, every year presents a new jigsaw puzzle.
You’ve got the puzzle pieces but there’s no box top that you can refer to when you start out to put the pieces together.
That could be an analogy for Mullewa farmers Rod and Andrew Messina, who in 2011 embarked on a farm project without a box top.
Armed with a theory that mouldboard ploughing could be another tool in the toolbox – to overcome non-wetting sands, mainly herbicide-resistant ryegrass and elevate subsoil pH with the introduction of lime at depth – 900 hectares of their 12,500ha (30,875ac) property was mouldboarded.
Roll on seven years and Rod and Andrew are still living the proverbial dream.
Commenting on their start into the unknown, Rod said: “We had no references back then.
“It was a concept borne mainly out of frustration of droughting crops from limited rain between 200 millimetres and 300mm.
“But it also was about adopting a more holistic approach to improving the farm’s productivity, especially on our less productive soils, and building soil structure to improve sustainability.
“So seven years on, yeah, we’re pretty happy how it’s all going.”
Mouldboarding their Eradu sandplain blocks was completed in 2015, the year they introduced so-called heliripping, using a Gregoire Besson Heliripper.
It’s a two-row three-point linkage hydraulically-operated bar with a six metre (20ft) working width with 13 tines spaced at 46 centimetres (18 inches).
The leading row of tines work at 50cm (20in), making it easier for the rear row of tines to work at 80cm (32in).
In combination, hardpans are broken and soil is fractured across the working width.
A rotary prickle chain was used in the first year but left the top soil too soft to seed into, so now they tow a tyre roller to consolidate the topsoil, allowing a better seed bed.
Having solved the non-wetting issue with mouldboarding and to a large extent herbicide resistance, the spotlight has focused more intently on subsoil acidity by introducing lime at depth.
“Hopefully we’ve fixed the 200-300mm (8-12in) of topsoil with an average six tonnes a hectare of lime between 2012 and 2016, elevating soil pH to 5-5-5.8,” Andrew said.
“Now we’ve got zones between 0-400mm (0-16in) where soil pH is 4.7 at 400mm and up to 6.5 at surface.
“So if we can get that pH up in that sub zone, hopefully the roots will keep going down.
“Historically roots haven’t been getting to that deep depth because of compaction and low pH although having said that you still get wheat roots at 1.2-1.5 metres (4-5ft) but there are not a lot of them.”
That’s where the Messinas see benefits in using the Heliripper on mouldboarded country.
“By digging deeper more lime can move through the profile to that depth because it’s not needed in the top soil, so hopefully it can start to elevate soil pH,” Andrew said.
His only disappointment was not putting on enough lime from the start.
“We started with rates of 1.3t/ha, then 1.5t/ha and finally 2t/ha,” he said.
“If I got to do it again I would put on 2t/ha the year before mouldboarding then apply 2t/ha in that first mouldboard pass, so you’d end up with 4t/ha of lime at depth for the next two years.”
So far the Messinas have heliripped 5200ha (12,844ac), applying 2t/ha of lime and by the end of this year the plan is that heliripping will be completed on the Eradu sandplain country.
This year they are also ripping some of the loams on the Tenindewa property to see what responses occur on that country.
It could be viewed as a whole-of-farm experiment in amelioration of sandplain and probably would get an entry into the Guinness Book of Records as the world’s biggest soil amelioration program.
“The big thing is to get organic matter back into the soil,” Rod said.
“We spread 50 per cent more straw these days to promote that break down in the soil which leads to a better structure and better moisture infiltration.”
Overarching the whole project is patience.
“You’ve got to be patient,” Rod said.
“Nothing happens overnight but we are seeing positive signs, particularly with our weaker country.
“In those drier years when that country would struggle we’re now seeing much better productivity.
“So we’re moving closer to drought-proofing the farm and in time the hope is that a more balanced and structured soil profile will not only provide bigger crop yields in good rainfall years, but also will provide a buffering effect in low rainfall years.
“I don’t think we would have got the same results from conventionally sowing.”
Weed burdens also are markedly reduced, impacting on chemical costs.
“We haven’t blanket-sprayed a lupin crop for radish since we started mouldboarding,” Andrew said.
“But while we’re basically on top of weed problems you’ve got to be vigilant and we would still be spraying between 10 and 20 per cent for radish in our lupin program.
“We still use our normal pre-emergent program along with a crop rotation that spreads the chemical groups but there are times when you’ve got to change because of weed levels or how good a job we’ve done with the plough.
“You never get things 100 per cent and the proof of decreasing weed seed burdens has to be over time.
“We’ve switched from burning windrows to chaff carts to reduce weed seed burdens and spreading the residue to mulch-in to build organic matter.
“It’ll be a long process because organic matter on these sands is very low.
“I’d say we’re in control but the pressure (on weeds) has to be maintained and while it costs us a bit, crop establishment is stronger and more even and we’re getting about a 500kg/ha response from mouldboarding.”
The brothers have no regrets about embracing the soil amelioration project, despite the high capital costs and high working costs ($80/ha an upwards).
Amortised over the residual life of paddocks, it’s a fairly cheap way to improve farm productivity.
“We don’t know when we’ll have to do the whole thing again but it has given us encouragement that we’re on the right track,” Rod said.
Interestingly, the mouldboarding has seen the emergence of mallees and blue gums which are dutifully pulled out by hand.
Next Thursday, March 23, Rod and Andrew will host a deep tillage day to share information and watch demos of various “deep rip” models including the Agrowplow, Ausplow Easitil, Bednar, Helios and Paxton Plow.
Contact Rod on 0428 611 630 for more information.