With the rapid advancement of non-chemical crop protectants and crop health technologies like inter row-cultivation and boosted plant immunity, modern organic farming methods are beginning to look very different from the ways of the past.
One organic farming family at Nadda, south-east of Loxton in South Australia's Murray-Mallee region, is embracing ag-tech and the opportunities it can bring to their cropping program.
In particular, Josh and Peri McIntosh are collaborating with a nearby organic farming family in trialling camera-guided inter-row cultivation as means to help control weeds.
Mr McIntosh said while summer weeds were a mixed blessing, as they helped provide soil cover over the hot months, in-crop weeds, especially ryegrass, were a major problem.
Without the option of cheap herbicide and unwilling to use excessive cultivation like long fallow due to its detrimental impact on soil structure, the McIntosh family are instead conducting trials with a customer designed inter-row cultivator.
"We leased a European inter-row cultivator in 2015 and found the guidance worked very well but the mechanical components didn't suit our conditions, so we built a hydraulic side-shifting headstock and fitted an off-the-shelf camera guidance system and hydraulic control unit from the UK," Mr McIntosh said.
"We then designed cultivator wheels to lightly work the interrow ridge while preserving the typical no-till ridge and furrow profile on 14 inch row spacings.
"At present it is only five metres wide, which makes it hard to get over a lot of country, but if it continues to prove itself in trials we'd look to scale it up," he said.
The accuracy of the camera guidance enabled accurate cultivation between disk seeder rows at just 170mm spacing in 2015.
It cleans up weeds with a system of rigid finger wheels which lightly work up the inter-row area, killing any emerging weeds.
"The prototype is based on European in-crop weed control systems used in row crops like corn, but we have the crop on the furrow instead of the ridge," Mr McIntosh said.
"You use it early on after germination, the earlier the better so you can stop weeds from establishing."
"The sensor uses a colour camera which means you don't go too close to the crop itself."
Mr McIntosh said it was slightly daunting taking a cultivating machine out into a paddock of emerging crop, but said the camera performed well.
"It's hard to trick the camera and if you can just see the green rows with your eyes then the camera guidance can see it too."
Along with the cultivator, there is another pass in-crop to apply a foliar spray to boost nutrient levels.
"We're not focusing on nitrogen because it is not a yield limiter, instead we're looking at trace elements, like calcium and zinc, it does contain a little bit of N, but it is more about the trace elements and bio-stimulants, which we are focusing on."
Bio-stimulants are mostly by-products of microbesthat have been found in trials to boost crop growth and provide greater resistance to crop disease.
"We put some nutrient on via a seed dressing and in-furrow liquid then we apply the foliar spray.
"The fish, kelp and mineral-based foliar sprays are made on-farm, we buy the ingredients and then use a bio-reactor to activate and multiply the beneficial bugs."
Mr McIntosh said making the bio-stimulant mix was similar to brewing, with the ingredients placed into the tank and kept at a controlled temperature to induce the growth of the microbes.