The South Australia No-Till Farming Association (SANTFA) plans to utilize ultra high-pressure (UHP) water jets to create the ultimate no-till farming system.
Ultra high-pressure jets are already used in many industrial applications as a cutter.
Greg Butler, SANTFA research and development manager, said research had showed interesting results in using the jets in farming systems as openings, similar to knife points or discs.
He said SANTFA had lodged a patent on a liquid coulter, while the UHP jets could also be used as a sowing system in their own right
“A liquid coulter, which could be supplied by manufacturers as an option on new seeding systems — or be retrofitted to existing seeding bars — comprises a UHP water jet integrated into a seeding system,” he said.
The cutting jet would most likely be positioned close to the soil ahead of seeding discs, although it could also possibly work in a tined system.
But going even one step further is an all-liquid system.
The concept of ‘aqua-till’ goes further than the liquid coulter by replacing the trailing disc or discs in a zero-till seeder with an air-gun to shoot seed into the furrow created by the UHP water-jet.
This has the potential to further reduce drought impacts and soil disturbance.
Butler said the vision for the ‘aqua-till’ seeder is to use a liquid coulter to slice through surface material and cut a narrow furrow into the soil, simultaneously depositing liquid nutrient along the seeding row.
The air-gun is positioned immediately behind the liquid coulter to deliver seeds into the furrow depository created by the liquid fertiliser jet stream.
The furrow is then closed with a seed-firmer or similar device such as a closing wheel.
Ideally, he said, the penetration of the liquid coulter and depth control for seed placement by the air-gun would be controlled by a mechanical or electromagnetic soil-density sensor that could be configured for soil type and crop requirements.