Research: Land management research to increase soil carbon sequestration - biochar
The secrets of soils are being unlocked by researchers at Industry & Investment NSW - Primary Industries, in their attempts to discover which types of land management practices best increase soil carbon sequestration. Farmers may in future be able to take part in an emissions trading scheme, provided soil carbon can easily be measured. This could mean an additional revenue stream when traditional revenue sources become less predictable.
Biochar is made by heating biomass under oxygen-limited conditions (pyrolsis).
Biochar is being investigated as one potential land management option. Biochar is the charcoal remains of burned organic (previously living) matter. This could be wood, plant material, animal manures or even vegetable scraps. This material is heated to 550°C in the absence of oxygen to create biological charcoal or biochar. (It is often also called 'agrichar' because of its use in the agricultural industry.) The biochar can then be crushed and added to soils to improve soil quality.
International and Australian research groups have confirmed the soil health benefits of the addition of biochar to soil:
- water holding capacity
- soil pH
- cation exchange capacity (CEC)
- tensile strength
- nutrient cycling/retention
- soil carbon
- soil biology.
Biochar has also demonstrated a reduction in soil nitrous oxide emissions.
When added to soils, biochar acts like a sponge for nutrients and water, which is great for soil fertility, and increasing farm productivity. If farmers add fertiliser to their soils, instead of some of the fertiliser being washed away with rainfall, more nutrients in the fertiliser stick to the charcoal components in the soil, and this enhances crop, pasture or tree growth. In some cases fertilisers may no longer be required, thereby further reducing nitrous oxide emissions associated with fertiliser production and application.
Studies have shown that biochar applied at a rate of 20 tonnes per hectare can result in 150% increases in corn yield.1
Biochar is also very stable, meaning that the carbon contained in the charcoal, which came about by burning carbon-containing organic products, is locked up for a long period of time, up to hundreds of years.
Locking the carbon in the charcoal can also result in an emission saving. If organic waste products were not transformed to charcoal, those products would have decomposed naturally by micro-organisms, releasing methane and carbon dioxide to the atmosphere.
The heat energy produced in the production process of biochar, called pyrolysis, is also a further option for energy production instead of burning fossil fuels. This is currently being investigated by BEST Energies Australia, a company with whom Industry & Investment NSW conducts collaborative research.
Industry & Investment NSW, in collaboration with BEST Energies Australia and the Ballina Council, is investigating options for establishing a slow-pyrolysis plant on the north coast of NSW, to supply biochar to NSW farmers.
Further information
Read further comprehensive information about biochar and the research.
Video
Watch this YouTube video about biochar:
This video is also available from the YouTube website at http://www.youtube.com/watch?gl=AU&hl=en-GB&v=nzmpWR6JUZQ .
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