[Terrapreta] VM composition

[Tom Miles]

Richard,

>Where there are no particular problems in soil fertility and organic matter
levels will a positive effect be shown by charcoal additions to soil? 

>our forest soil here that are mycorrhizal fungus dominated, highly leached,
and have abundant annual organic matter input from leaf/needle litter and
woody debris. What role might charcoal play in such a place?

These are fundamental questions that get at the agronomic and economic value
of using charcoal. If people can appreciate a value from charcoal at home
they are more likely to help promote it on poor soils where it has clearly
demonstrated benefits.

I'm encouraged by the success on field crops - wheat and soy - recently
reported in Australia. I haven't seen test data yet for work on field crops
in the US or on temperate crops in Europe. 

I also wonder if there is a benefit for plant health and water conservation
in urban gardening and landscaping. A soil mix or applied (hemlock bark)
mulch here costs $240-$300/200 ft3 unit ($42-$53/m3, 5.66 m3/200 ft3). The
organic mulches break down in 2-3 years and we are left again with hard
clay. Would addition of 20% by volume (40 ft3/200 ft3), or 10% by weight,
improve the soil, plant health and conserve water on our soils? Positive
results could give soil amendment companies a new product and new market
which could drive production and use.

It's always difficult to keep water on a newly constructed berm. Could
charcoal be used to improve water and nutrient retention on a berm?

Should VM be part of a charcoal specification for these applications, or
does it matter?     

Many questions

Tom Miles