Biochar trials look promising

Kathryn Dryden
June 7, 2016

Biochar trials look promising

Michael Rocca and his Biochar

Nitrogen loss through runoff and leaching is a major issue for farmers in the Wet Tropics, and one Mareeba farmer is manufacturing and trialing his own solution.

Michael Rocca has been trialling biochar on his cane, peanuts and maize crops for the last five years and has had great results.

Biochar is biomass (plant material) burned in a low oxygen environment resulting in permanent storage of carbon in the soil. “I have been involved for some time in trialing the biochar in partnership with Terrain NRM, Northern Gulf Resource Management Group and James Cook University,” he said.

“It has proven to be a highly effective addition to my soil for both increasing yields and stabilising nitrogen. Its wider use has been limited by both supply and cost, so I thought I’d make my own.”

Michael said, “The loss of carbon in the soil is a big issue for me, which was part of my motivation to get involved. Biochar permanently lifts soil carbon and stays in the soil. It doesn’t break down so I can take advantage of its benefits over the long term.”

The product is like a sponge and has many benefits including its ability to hold moisture, regulate pH and increase carbon in the soil.

When coupled with a fertiliser, it retains the nutrients and makes them available to the plant at its root zone. Whilst enhancing plant health and yield, it also benefits water quality as less nitrogen is leached into the environment and to the Reef.

Michael has seen an improvement in soil health, yield, leaf size and root development over a range of trials on different crops as a result of using the biochar. “I have seen an increase in yield to the tune of around 10-15%,” he said.

Having built two self-funded prototypes for biochar manufacture, Michael gained some funding through Terrain NRM from the Australian Government’s Reef Programme to further the project. He is working toward producing the biochar so it’s affordable for growers to trial commercially.

He said, “I’m in the process of building a third prototype which will allow me to produce 700kg per hour of the product. Previous prototypes would only make around 45kg per hour. With the new machine, what was taking one day to make will now take three times that in one hour!”

The aim of the Michael’s biochar project is to undertake trials and get the application right. Terrain’s Gavin Kay said, “The use of biochar goes back to the tera-preta soils in the Amazon thousands of years ago, but its application in our region is very new. Terrain is excited to be supporting Michael and his innovation as one potential solution for improved farm management and water quality outcomes across the region.”