Task: Nitrogen fertilization may be needed to prevent stalling when charcoal is used fresh. This could easily persuade gardeners to overcompensate with excessive fertilization. The following approach demonstrates that only a few grams of fertilizer per kg charcoal should be sufficient.

Target: 10-50 kg N ha-1 at 50 Mg C ha-1

Rationale: This is on the order of what is needed to prevent stalling when a new crop is seeded into land where grain stubble was incorporated, from a range of light to heavy stubble.

Sources of soluble N for soaking charcoal:

Product: N content (dry wt basis)

Urea: 32%

Ammonium Sulfate: 24%

MiracleGro(TM): 15%

Example calculation:

50 kg N : 50 Mg C = 1 g : kg

1/32% = 3.125 g Urea needed per kg charcoal

1/15% = 6.667 g MiracleGro(TM) needed per kg charcoal