Johnson-Su Bioreactor Compost — FarmPal

Developed at New Mexico State University. Creates fungal-dominant compost ideal for inoculating soil biology. Static, aerated system that favors beneficial fungi the missing link in most soils.

Time to Finish
12-18 months (but set-and-forget)
Space Needed
4-foot diameter wire cylinder, 5 feet tall

🟢 Greens (Nitrogen)

  • • Green plant material
  • • Kitchen scraps
  • • Manure (diverse sources ideal)

🟤 Browns (Carbon)

  • • Wood chips
  • • Straw
  • • Dried leaves
  • • Cardboard

Steps

  1. 1Build wire mesh cylinder (welded wire, 4' diameter, 5' tall)
  2. 2Insert 4-6 PVC perforated pipes vertically for passive aeration
  3. 3Fill with mixed materials standard 25:1 C:N ratio
  4. 4Moisten to 60-70% moisture
  5. 5Cover top loosely to retain moisture but allow gas exchange
  6. 6DO NOT TURN the whole point is maintaining fungal networks
  7. 7Keep moist water weekly if needed through PVC pipes
  8. 8Mature in 12-18 months dark, earthy, visible fungal threads

Troubleshooting

⚠ Not decomposing
✓ Check moisture the most common issue. Should be moist throughout.
⚠ Smells bad
✓ Too wet or too compacted. Open aeration pipes, add dry material on top.

Tips

  • 💡Dr. David Johnson's research showed this compost dramatically increases soil carbon sequestration
  • 💡Fungal-dominant compost is what most degraded soils desperately need
  • 💡Use as inoculant a little goes a long way (seed coating, transplant dip, soil drench)
  • 💡Recent 2025 studies confirm fungal-dominant soils have 5-8x greater water-holding capacity
  • 💡The key insight: NOT turning preserves the fungal hyphae that most composting methods destroy