How to Make Biochar
Organically Improve your Vegetable Garden Soil
Biochar is a method of effectively and organically rebuilding the soil in your vegetable garden or farm. It is actually an ancient practice that was used by Natives in the Amazon’s Rainforests thousands of years ago, called Terra Preta. With long term soil improvement capabilities, biochar can increase vegetable and crop yeilds. And since it has the potential to reduce carbon gasses, biochar has recently gained momentum and media attention.
In very simple terms, using biochar is the practice of incorporating burned organic matter in the soil of your vegetable garden. Biochar is a fine-grained charcoal produced from organic matter (plants, garden wastes, brush, even bones.). For an organic nutrient source for your vegetable garden, use only organic materials for the base of your biochar effort.
Note: You may want to try this method as a way conquer weedy sections of your garden. It not only improves the soil there, but it will eliminate those pesky weed seeds and provide a “clean” fresh start.
Benefits of using biochar:
- Immediately lowers your soil acidity
- Improves your soil quality, adding very badly needed nutrients for your garden, and acts as a long-term fertilizer (often with significant results in plant growth and yield)
- Helps the soil retain nutrients (like nitrogen, calcium, phosphorus), compost, and beneficial microorganisms much more effectively than unimproved soil.
- Helps your plants utilize and absorb more nutrients from the garden soil, particularly when used in conjunction with compost or well-rotted manure (thus packing your vegetables with a higher nutrient content).
- Reduces groundwater pollution.
- Reduces the need for irrigation.
How to make biochar:
Wait for a calm (No Wind!) damp day (when both the soil and the groundcover is damp). Clear the area of your burn from any loose burnable matter (leaves, twigs etc.). Dig a trench in your vegetable garden, and loosen the soil at the bottom of the trench. Add your brush, or other organic matter to the ditch (keeping the majority of the material as dry, ignitable matter).
Note: Keep the trench and pile small enough that you can easily monitor and control it (so that the fire doesn’t get out of hand).
Light the pile (avoid the temptation to use gasoline or other chemicals to start your fire… that’ll add harmful chemicals to your soil!). The goal is for the fire to burn fast and hot, at first. When the smoke finally turns a grayish color, cover the pile with dirt to cut off the oxygen. Let it smolder until the larger pieces are about the size of chunks of charcoal. Then douse the embers with water to put the fire out. Monitor your fire until it’s completely out. Even embers or small coals can start out-of-control fires.
Note: Having an open fire such as this, requires your full attention. Check with your town authorities to see if you need a permit before you burn (you don’t want the firemen showing up at your door, hose in hand!).
Biochar is used by mixing it in with your gardening soil, as you would compost or other organic matter. Or, you can include when making compost with your other organic matter scraps. You may find that including (fine granuled) biochar with your compost actually helps speed up the composting process. Keep the percentage of biochar to less than 50% of the matter in your composter or compost pile, to keep your earthworms operating at their fullest capacity.
Note: Be sure to mix biochar into soils that have been (or are being) enriched with compost or well-rotted organic material, or else it may cause the opposite effect and stall your plant growth.
For a more scientific approach on how to make biochar, benefits, and a variety of studies, visit these sources:
Note: the advice and information contained herein is based upon our experience and study. As with any advice, please apply at your own discretion.