The natural geological features of cropping land in Western Australia pose many and varied challenges to growers – among them the management of lateritic reefs.
Often presenting as caps on higher country, lateritic reefs reduce productive area in paddocks, shed water, harbour weeds and pests and impede and wear machinery, creating driver fatigue during operations.
Growers are adopting innovative mechanical means to deal with these obstructions using reefinators. Among these growers is Scott Young, who farms at Cuballing.
“Our country is criss-crossed with laterite reefs and rocky outcrops,” Scott says.
The rock is a conglomerate of ironstone pebbles and clay and can be smashed with a hammer or crumbled by hand.
“Where previously we would have navigated around these non-arable areas, we now have machinery that can bring them into cultivation,” he says.
“This creates many advantages – not only increasing production, but also I can better-manage weeds and pests, and machinery wear and driver fatigue are significantly reduced.
“Reefinating these regions removes obstacles and also reduces overlap of both seeding and spraying operations.”
A reefinator is connected to a drawbar. It is usually about three metres in width, with hydraulic tynes that can bite into laterite rock and a ribbed roller bar behind, which when fully ballasted with water can weigh about 18 tonnes.
The unit is pulled at about eight kilometres per hour and the ensuing momentum also helps to smash the rocks. It can take six to seven passes over a patch of affected ground to pulverise the laterite into a suitable seed bed.
Scott farms 3000 hectares and estimates that 15 to 20 per cent of the property has laterite reefs.
“I started reefinating four years ago with an aim to treat 75 hectares, at a rate of 15ha a year. I am about halfway to this goal.”
Reefination is slow work and can cost up to $600 per hour, so Scott sets an annual budget.
“The price of land is at a value that it is more profitable to bring this land into cropping than purchase more land,” he says.
Measuring and monitoring is an important part of Scott’s cropping operations and every 12 months he soil samples 16 sites across his property. This means every paddock will be checked every four to five years to monitor nutrient levels.
Yield maps are also a very important part of his monitoring as they provide a visual appraisal of crop performance every year, creating a valuable temporal and spatial record.
Scott is a member of the Cuballing Top Crop group serviced by ConsultAg, which also provides agronomic advice to him. It was through these connections and the provision of his crop monitoring history that Scott volunteered to provide his reefinating records for a GRDC project taking a deeper dive into the crop and financial aspects of reefinating.
The study has shown that it could take three years to break even with reefination amelioration.
Moreover, Scott says the indirect benefits of reefination to his business operations are considerable.