Biochar Use in Soils

Biochar enhances soils. By converting agricultural waste into a powerful soil enhancer that holds carbon and makes soils more fertile, we can boost food security, discourage deforestation and preserve cropland diversity. Research is now confirming benefits that include:

• Reduced leaching of nitrogen into ground water
• Possible reduced emissions of nitrous oxide
• Increased cation-exchange capacity resulting in improved soil fertility
• Moderating of soil acidity
• Increased water retention
• Increased number of beneficial soil microbes

Biochar can improve almost any soil. Areas with low rainfall or nutrient-poor soils will most likely see the largest impact from addition of biochar.

IBI has created two sets of guidelines regarding biochar and soils: 

• Guidelines for setting up field trials
• Guidelines for biochar application to soils

There are a number of publications on biochar and its effect on specific soil types in specific conditions. For more information on these topics, you can search the IBI Biochar Bibliography.

Biochar and Terra Preta Soils

Biochar production is modeled after a process begun thousands of years ago in the Amazon Basin, where islands of rich, fertile soils called terra preta ("dark earth") were created by indigenous people. Anthropologists speculate that cooking fires and kitchen middens along with deliberate placing of charcoal in soil resulted in soils with high fertility and carbon content, often containing shards of broken pottery. These soils continue to "hold" carbon today and remain so nutrient rich that they have been dug up and sold as potting soil in Brazilian markets.

Rural and Developing Country Applications of Biochar Systems

Biochar systems can reverse soil degradation and create sustainable food and fuel production in areas with severely depleted soils, scarce organic resources, and inadequate water and chemical fertilizer supplies. By making croplands more fertile for longer periods of time, biochar discourages deforestation. Low-cost, small-scale biochar production units can produce biochar to build garden, agricultural and forest productivity, and provide thermal energy for cooking and drying grain. With the addition of an engine or turbine, these systems can produce kinetic energy for grinding grain or making electricity. Click here for more information specific to biochar projects in developing and emerging economies.

(Upper photos courtesy of Julie Major and Bruno Glaser; lower photo courtesy of Julie Major.)