Characteristics and Function of Charcoal
From: Makoto Ogawa, Effects of Soil Microbial Fertility by Charcoal in Soil
1.Porous substance with high water and air holding capacity; Suitable habitat for some microbes and plant growth, good material for soil amendment, absorption of chemicals and humidity control
2.High alkalinity; Neutralization of acidic soil and improvement of chemical components of soil and selection of microorganisms
3.Non organic matter ; Exclusion of saprophytes and propagation of autotrophic and symbiotic microorganisms, free living nitrogen fixing bacteria, root nodule bacteria, Frankia and some mycorrhizal fungi
4.Low mineral content ; “Charcoal has no role as a fertilizer”
Composition of bark charcoal %
Carbon:77.58,
Volatile matter:12.92,
Ash: 9.50
Mineral content of ash %
SiO2:36.5
Al2O3:10.9
CaO:19.2
K2O:1.1
Na2O3:5.35
Fe2O3:7.5
MgO:10.3
P2O5:1.7
# Air supply by charcoal induces the activation of soil microbes and CO2 emission temporally. Small amounts of chemical fertilizers or organic matter should be mixed with charcoal in agricultural use.
soil application of charcoal to provide a microhabitat for AM fungi to colonize and survive.
See: The Benefits of Charcoal in the Soil (Research Links) EPRIDA
Nutrient adsorption by fresh charcoal
As I understand it, adding fresh charcoal to the soil would have an initial effect of removing nutrients from the soil. After the sites are fillded up, the typical 'Terra Preta' effect would add on.
Adding nutrients to the char previous to the addition to soil would reduce/reverse this initial effect.
For example, adding urine.
Does anybody have any idea of the specific adsorption capacity for charcoal on nutrients?
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Folke Günther
Lund, Sweden
www.holon.se/folke