WANTING to incorporate multi-species pasture cropping in his kikuyu-thatched paddocks to help fill feed gaps, Koolah Angus Beef producer Derek Walter invested in a unique seeding and aerating machine called a Soilkee Renovator.
Derek recently gave a demonstration of the machine during an Agritech Road trip on the Fleurieu Peninsula.
With wife Sarah and parents Vic and Helen Walter, Derek runs 80 Angus breeders on 150 hectares at Willow Creek, alongside leasing out a secondary dairy farm.
A third of the farms (110ha) is covered in thick kikuyu, sown decades ago on less productive, heavy sands.
"While kikuyu is a good hardy plant for a feed source, it goes dormant in the cold of winter and doesn't grow when there's no moisture in summer, while outcompeting any other plant in its path," he said.
Not wanting to use "a tonne of chemical" to get rid of the kikuyu, Derek found potential in regenerative practices to cope with the hardy grass, and also came across the Soilkee Renovator.
"After the input costs of producing beef kept rising 10-15 years ago, we couldn't afford to keep loading on fertiliser and chemicals as we were so we looked into other options," he said.
"We have been experimenting with alternate fertilisers and soil amendments since then."
Derek said the Soilkee was also ideal as it could "mechanically get new seed into the soil, without the use of herbicides or fertilisers".
[The Soilkee Renovator] provides the best of both worlds - cultivation to get the seed in, but minimum-till to reduce soil and microbial disturbance.
- DEREK WALTER
The Australian-made minimum-till cultivator uses rotary blades to cut through the soil, but leaves at least 80 per cent of the pasture undisturbed.
It was invented by Vic farmer Niels Olsen, who was also looking to fill the summer feed gap in their system.
"Another upside to a machine that can drill into a perennial pasture, was the benefits to the microbial diversity under the soil and the carbon-building potential of it," Derek said.
"The blades don't disturb all the soil, because as soon as you start turning over soils, that's when you start burning off soil carbon.
"It provides the best of both worlds - cultivation to get the seed in, but minimum-till to reduce soil and microbial disturbance."
The machine can also drop a diverse mix of seeds into "a competition-free seedbed for successful germination", while "the undisturbed portion acts as a cover crop protecting the soil from the elements, reducing erosion and keeping around 80pc of soil life habitat intact" - the company said.
Derek said they received the machine in October and got to work, covering 10ha in November using Soilkee's 'premium seed mix', which includes wheat, barley, triticale, oats, peas, vetch, ryegrass, chicory, plantain, brassica, tillage radish, subclovers and red clovers.
"From a regenerative point of view, you want plant diversity and microbial diversity in the soil," he said.
"That's how you get the most activity out of your soils, and keeping up microbial activity in your soils keeps your soil temperatures up, which helps to grow things for longer in winter. Add in soil carbon through multi-species crops and leaving leaves alive, instead of spraying them out and killing them, you also improve water infiltration and retention."
They had the rotating blades at a depth of 100 millimetres, which got through the kikuyu "really well", however being the end of November, there wasn't a lot of soil moisture and germination was poor in some areas while persistence was poor in general.
They went back over the same ground from mid-March on a different angle, and have since covered 40ha of both kikuyu and non-kikuyu country.
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"The more you use the machine, it really cuts down into the kikuyu thatch and if we can break it up mechanically, we can get other plants to compete in the pasture," Derek said.
"The germination we are now seeing through our carpet of kikuyu is the reason we bought this machine.
By owning a Soilkee, the Walters have been approved under the Emissions Reduction Fund, as the machine is recognised as a sufficient management change to build soil carbon, and through soil carbon mapping company Agriprove, they have already measured the baseline levels on the beef farm for potential carbon credits in future.
"The response I have seen from the pastures using this machine, I believe we will be building soil carbon," Derek said.
It has also helped towards ceasing the use of fertilisers.
"We haven't noticed much of a production loss from removing fertilisers, however we did notice a very big change to what was growing," Derek said.
"The weed burden increased massively in the short term, which we believe was due to the pastures we were sowing requiring fertiliser to grow, so then they became less competitive.
"We are now using Down Under Covers pasture mixes, as it is produced in a regenerative manner, so the seeds aren't reliant on soluble fertilisers to thrive."
Moving away from an industrial system to following a regenerative system, has allowed the soil to do what it does well naturally, rather than chemically altered.
- DEREK WALTER
Regenerative grazing has also stopped the family needing to produce hay and silage.
"We haven't supplementary fed since 2017," he said.
"Moving away from an industrial system (trying to control every aspect of what you are doing using chemicals) to following a regenerative system, has allowed the soil to do what it does well naturally, rather than chemically altered, we then monitor it and make management decisions accordingly."
Derek said the machine was a big investment ($80,000 at the time), but it is "a seeder, aerator and remineraliser, all in one, without the need for sprays and fertiliser".
"And with the price of diesel now, we can do this all in one pass," he said.
"It is the best thing we could have done."