SA FARMERS are set to benefit from a centuries-old process used to help retain nutrients, improve soil structure and increase its water-holding capacity.
At the unveiling of Clean Carbon's Green Flame biochar machine at the SANTFA annual conference on Friday, executive director Greg Butler said the product could be used to achieve targeted agronomic benefits.
Biochar trials have been run across SA for the past six years, and Mr Butler said they had seen "some excellent" cost benefits.
"Trials have been subcontracted to independent researchers such as Leighton Wilksch on the Yorke Peninsula and SARDI in the Mallee, and have shown some excellent results," he said.
"We now understand biochar much better than we did a few years ago."
Results from trials conducted at Minlaton in 2012 and Paskeville in 2013 showed that using a mix of 35-kilograms-a-hectare of biochar and 50kg/ha of DAP produced crop yields significantly better than 50kg/ha of DAP alone and equivalent to applying 100kg/ha of DAP in statistically replicated trials.
"This is a significant benefit and opportunity to reduce input cost and risk," Mr Butler said.
Designed and built in conjunction with SJ Cheesman's Stephen Richter, Port Pirie, the Green Flame demonstration machine has a feed-in rate of 150kg an hour, is simple to operate and priced at "well under" $100,000.
Mr Butler said the continuous-flow machine produced high-quality char, and could also generate heat energy if required.
"It's a way to value-add to a product," he said.
"We have 12 demonstrations lined up over the next few weeks."
Despite being a relatively new concept in Australia - biochar was first used in farming systems in South America 6000 years ago - Mr Butler said there were many ways producers could use the product.
"Some are higher-risk strategies that keep fertiliser rates high, and add char to it and hope that at an extra cost you get a higher yield," he said.
"The other, my preferred option, is a lower-risk strategy - to reduce your up-front fertiliser costs and supplement that with biochar and still achieve the same yield - if you believe your biggest yield constraint is rainfall.
"If you're going to be limited by rainfall and you have soils that lock-up fertiliser, to add less and get the same yield seems like a lower-risk proposition to me."
Clean Carbon began in 2008 and Mr Butler said the company developed Green Flame as a cost-effective alternative to high-spec pyrolysis machines.
"There is a lot of capacity to make biomass into energy," he said.
"Without getting too technical about it, basically the lower the temperature the higher the quality of the biochar for agronomic purposes, but the higher the temperature you use, the better it is for energy purposes.
"We decided to focus on a biochar machine for producing char for the best agronomic performance."
* Full report in Stock Journal, February 27, 2014 issue.