Making and Using Biochar — FarmPal

Create stable carbon from organic material to improve soil and sequester carbon for centuries.

Time Required
2-4 hours per batch
Season
See notes

Benefits

  • •Sequesters carbon for 1000+ years
  • •Improves soil water retention
  • •Provides habitat for beneficial soil microbes
  • •Increases nutrient availability
  • •Uses agricultural waste productively

Steps

1
Understand the Process

Biochar is created through pyrolysis heating organic material in a low-oxygen environment. This creates stable carbon rather than ash.

  • 💡 Top-lit updraft (TLUD) gasifiers are efficient for home scale
  • 💡 Pit burning is traditional and low-tech
  • 💡 Temperature and oxygen control are key
2
Prepare Materials

Use dry woody material like prunings, corn stalks, or nut shells. Uniform size ensures even charring.

  • 💡 Material should be thoroughly dry
  • 💡 Smaller pieces char more quickly
  • 💡 Hardwoods produce denser biochar
3
Char the Material

Using TLUD, pit burning, or retort method, heat material until it becomes char but before it becomes ash.

  • 💡 TLUD: light from top, char falls as it burns
  • 💡 Pit: cover with soil to stop oxygen
  • 💡 Char should be light but not powdery
4
Quench and Crush

Stop the burning process with water or by smothering. Crush char to increase surface area.

  • 💡 Quench thoroughly char can reignite
  • 💡 Crush to roughly pea-sized pieces
  • 💡 Wear dust mask when crushing
5
Charge and Apply

Biochar must be "charged" with nutrients before adding to soil. Mix with compost, urine, or fertilizer.

  • 💡 Uncharged biochar can temporarily tie up nutrients
  • 💡 Add to compost pile to charge naturally
  • 💡 Apply 1-2 lbs per 10 square feet

Tools Needed

Drum or barrel for TLUD
Shovel for pit method
Water for quenching
Crushing tool (roller, stomping)
Buckets for storage
Compost for charging

⚠️ Safety

  • •Fire safety clear area, have water available
  • •Smoke exposure work outdoors with good ventilation
  • •Dust from crushing wear mask
  • •Check local regulations on outdoor burning
Seasonal Notes
Make biochar during dry seasons when fire risk is managed. Apply to beds in fall or spring.