What is Biochar?

Biochar is a highly adsorbent, specially-produced charcoal originally used as a soil amendment. Researchers theorize that biochar was first used in the Amazon Basin thousands of years ago where expansive regions of dark, highly fertile soil known as terra preta were discovered, revealing high concentrations of biochar and organic matter.

Similar to charcoal, biochar is produced using the ancient practice of heating wood or other plant material (biomass) with little to no oxygen. However, unlike charcoal, which is often used for cooking, biochar is made under specific conditions with the intent to be applied to soil as a means to increase soil fertility and agricultural yields, and sequester carbon to reverse global warming. Other market uses of biochar are being discovered regularly as universities conduct extensive research into this versatile material and its cation exchange properties.

Biochar is thought to be the key component in a carbon-negative strategy to resolve several critical current ecological and energy challenges.

Biochar in Agriculture

Increases in soil fertility are attributable to biochar’s unique properties of adsorption and stability. Compared to other organic soil amendments, biochar is much more effective at retaining nutrients and making them available to plants. Biochar maintains a porous structure, which attracts beneficial microbes, holds onto nutrients, retains moisture – qualities that increase fertilizer efficiency and enhance crop yield, while reducing the need to irrigate. And history confirms biochar is much more stable in the environment than any other form of organic matter. By storing organic carbon, biochar provides for an exceptionally long life – thousands of years in fact.

Research shows biochar has several effects in soil including:

  • Increased water infiltration and water holding capacity
  • Improved soil structure, tilth and stability
  • Increased cation exchange capacity (CEC)
  • Increased adsorption of ammonium, nitrate, phosphate, and calcium ions
  • Increased nutrient retention over ordinary organic matter
  • Improved soil pH buffering and stability
  • Increased soil biology and diversity
  • Enhanced, denser root development
  • Reduced fertilizer runoff, especially nitrogen and phosphorus
  • Reduced total fertilizer requirements
  • Decreased plant uptake of soil toxins
  • Decreased emissions of nitrous oxide

Biochar for Soil Reclamation

Biochar offers an extremely cost-effective solution to bind toxins and prevent their leaching into surface and ground water. And, as a bonus, the once sterile soil can now support plant growth.

By sequestering the heavy metals and acids in the soil surrounding abandoned mines, biochar prevents these contaminants from leaching into local water supplies–and immobilizes them long enough so they degrade naturally. Secondarily, biochar quickly facilitates the reestablishment of vegetation on this typically sterile ground with improved soil fertility, increased infiltration, and reduced erosion. Moreover, biochar can accomplish mine reclamation quickly and at a mere fraction of the cost of removing tailings to hazardous waste sites.

Important Properties

  1. The long pores provide significant surface area.
  2. Biochar has a cation exchange capacity that electrostatically attracts certain types of molecules including Nitrogen and Phosphorus nutrients in the soil, air and/or water. The molecules are lightly bonded to the biochar walls where roots can access them throughout the growing season. The biochar becomes a nutrient-rich, time-release capsule for plants and is a major reason why biochar is so effective enhancing plant growth. 
  3. Biochar has been tested for water sequestration and found to hold 5.6 times its weight in water. And, because the pores are very long compared with their openings, there is very little evaporation. When roots do not consume the sequestered water, it is held for long periods of time.
  4. To soil microbes, cleaned out biochar pores look like a concrete condominium complex so they move in to set up family and community. Once embedded, they are protected from precipitation that would otherwise disperse them. With biochar, microbes flourish and help create living soil.

How is Biochar Made?

PYROLYSIS

Pyrolysis is the process by which biochar is produced. Fast or slow pyrolysis, in tandem with choice of feedstock, has the greatest impact on the resulting biochar.

Fast pyrolysis quickly increases temperatures into the moderate to high ranges in order to accomplish rapid conversion of feedstock to biochar.

Slow pyrolysis gradually and evenly heats the feedstock and does well to account for differences in moisture and feedstock size inconsistency.

Advances in Biochar

Interested in Learning More?

To learn more about the advances in Biochar products, systems, and processes download the PDF power-point presentation below.

Download Biochar PDF