Biochar is the product of controlled combustion (pyrolysis) of select feedstock materials. Feedstock can include woody plants and grasses, agricultural byproducts such as corn or sugar cane stover, or even human and animal manures. Often used as a soil amendment, the high carbon end product (biochar) is extremely stable as it is slow to decompose and can have long lasting benefits for a soil’s health.
With a light weight and extremely high surface area for its volume, the porous nature of biochar provides many benefits as a soil amendment. While improvements to fertility seem to be limited in temperate environments, biochar’s soil health benefits generally include:
- Increased nutrient holding capacity and availability for plant uptake
- Less nutrient loss through leaching
- Improved soil biome diversity and functionality
- Increased water holding capacity while maintaining good drainage
- Liming effects in low pH soils
Biochar should not be viewed as a fertilizer as it typically does not have a high nutrient content. But as noted above, biochar will improve nutrient availability and retention as less nutrients will be lost with water leaching from the root zone and therefore available to plants.
While backyard charcoal production is possible, proceed carefully as charred materials can have detrimental byproducts, including the gasses and smoke released. The properties of the biochar products are strongly influenced by the types of feedstock, the temperature of pyrolysis, and the amount of oxygen present during the burn. Not all biochars are beneficial to the soil, or to those working with the soil.
Before applying biochar, visit the New York Soil Health website and click on their FAQs to learn more about biochar and how to use it. They also have a resource library with information about the biochar producers and quality of the products available in your area that will help you find a beneficial, effective solution for your soil.
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