The Environmental Significance of Biochar
Biochar is a charcoal-based carbon rich by-product produced by the downdraft gasification of biomass feedstock. This material presents with a fine-grained, highly porous structure that has a very high BTU content and exceptionally high carbon content levels. The physical properties and characteristics of Biochar see it becoming an increasingly sought after material as a soil amendment/additive for agriculture, horticulture and land rehabilitation. According to the International Biochar Initiative, Biochar is found in soils around the world as a result of vegetation fires and historic soil management practices. Intensive studies of rich dark soils in the Amazon called “terra preta” has led to a great appreciation of the properties of this unique material as a soil conditioner. In Australia there is also clear evidence of it's importance and heritage use by the Aboriginal's use of fire management where carbon was deliberately returned to the land through fire.
- Some of the agronomic benefits of using biochar as a soil conditioner are:
- Increases water retention, thus reducing irrigation volumes and allowing for crop growth in arid areas where water is a premium.
- Increases beneficial microbial activity and so increases crop yields whilst reducing fertiliser use, costs and the resultant excess nutrient run-off which causes damage to sensitive natural areas such as reefs and coastal wetlands.
- Moderates soil acidity
- Reduces leaching of nitrogen into ground water
- Improves cation-exchange capacity
- Additionally, Biochar has a range of other uses such as:
- Fuel for kiln type operations or where a solid fuel type is required
- Filtering media in a number of industries and varied applications from liquids, gases and odours
- Growth foundation for in marine applications such as reef regeneration
