While most people would think of water jet technology as something for cutting steel or granite, a farming systems group has adapted the technology as an innovative way to seed through high stubble loads.
Speaking at the Grains Research Development Corporation (GRDC) Grain Research Update held in Goondiwindi, Qld, South Australian No-Till Farmers Association (SANTFA), research and development manager, Greg Butler said the innovative technology, known as Aqua-Till, developed from a need to improve sowing while maintaining a low soil disturbance, stubble retention farming system.
"Residues are king in our system, people recognise that stubble is money," he said.
A survey of 500 SANTFA members kicked off the project, identifying significant issues in seeding under heavy stubble loads, including tyne blockages, clumping on rows, soil throw and hair-pinning.
"Following the survey we considered making a slightly better tyne or a slightly better disc, but we didn't want to do that," Mr Butler said.
"We looked at liquid cutting technologies and formed a relationship with Flow International, the leading high pressure water company in the world."
Created by putting water, at about 55,000 psi of pressure or 3800 bar, through a nozzle eight one-thousandths of an inch in diameter, the AquaTill liquid coulter travels at about three times the speed of sound, allowing it to cut through living or dead plant residue.
Mr Butler said the technology had been tested on a variety of crops and residue levels, showing impressive results even on ones with tough, ropey residue such as linseed.
"It has high cutting capability on wheat straw and is a great fit for residue handling in no-till planting applications," he said.
"The potential value of this technology, is reinforced by new data showing it is particularly effective in wet stubble and soft soil environments."
Mr Butler said results from research on the technology conducted bu the Agricultural Machinery Research and Design Centre at the University of South Australia, funded by the GRDC, showed 150 litres per hectare of water could sustain straw stem cutting capacities up to 12.5t/ha at 300 millimetre row spacing or at 35t/ha at 1000mm.
"Waterjet cutting technology is well suited to wider row spacing's, where a given cutting capacity can be achieved with relatively less water per hectare," he said.
Mr Butler said the technology had been trialled applying fertilisers such as UAN as a nitrogen source at planting as well as other combinations.
"Looking at the side profile as the system cuts into the ground it could deliver some nutrients there," he said.
"This could mean lower seedbed toxicity which is of interest to us to sow small seeded crops, such as canola, with high fertiliser rates into marginal moisture.
"A water jet can cut two metres of stainless steel, so if we want to put phosphorus or lime down to 60 centimetres we should be able to do that."
Mr Butler said the Aqua-Till liquid coulter was in the early stages of commercialisation, with planting manufacturer, NDF hoping to deliver two products to market.
"Flow International own the international patent on the technology, however the licencing of that we made sure any manufacturer that is interested in making the engagement tool can have their own IP and can do so," he said.
"Any manufacturer looking at taking this on it isn't an exclusive deal or if someone wants to add AquaTill to their own seeder they can do so."