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How to make fertilizer from biochar

Biochar has a porous structure and functions as a water and nutrient storage. A very easy way to enhance your soil, save water and boost your harvest. In our tests in Ghana, we showed an increase in crop yield of over 400%.

Done in 14 days
Skill level basic

Published under CC:BY-NC-SA by


Author · Walter Danner

What you need

You decide the amount. You have to take as much manure as biochar.

How you make it

Charge your biochar with nutrients

At first it is necessary to charge the biochar before applying it to the soil. Add nutrients e.g. chicken droppings. Examples are fresh or matured manure (from any livestock) and compost. You can also mix them. Pile up your biochar and add water until it leaks out. Mix in your solid nutrient source in a ratio around 1:1.

Let it sit for 14 days and keep it moist to help the nutrients move.

Store the charged biochar or use it right away.

Charged biochar can be stored. Keep it moist and in contact with air so the microbes stay alive.

How you use it

Root zone application

Root zone application needs the least biochar per area. The roots have immediate access. Because the biochar is not distributed evenly, it has to be reapplied the next year for the same results.

  1. Dig your planting holes
  2. Fill the bottom with some biochar
  3. Cover it lightly with soil
  4. Plant on top of it

Root zone application is great for all plants. Especially for deep rooting ones like tomatoes or squash.

Full Field Application

Incorporate (by tilling or plowing) the biochar into the topsoil as deep as the roots will be (-20 cm). This application is great if all of your soil needs structural improvements (sandy soil or clay soil).

  • Light: 0,1 kg / sqm = 0,25 l / sqm
  • Medium: 0,5 kg / sqm = 1,25 l / sqm
  • Strong: 1 kg / sqm = 2,5 l / sqm

For potted plants and nursery trays you can mix biochar and soil 1:10. You can always reapply to get a stronger result.

Trench Application

If you missed adding biochar during the planting, you can use this method to apply biochar to perennial plants.

  • Dig a trench around your plant at the drip line (arrow)
  • Fill it with charged biochar
  • Cover it with soil

For bushes and vines (e.g. grapes or tea) you can also dig straight trenches between your plants. The roots will grow towards the biochar.

Top Dressing

Apply the biochar at the base of your plants or over the whole area. Combine the biochar with mulch or compost to prevent it from running off with rain water or being blown away. This type of application might not show results right away. Biochar is most effective at the roots of plants. It will take time for worms and microbes to fully incorporate the biocar. This is a great solution for no till systems.

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