Hi Phil,

I don't use charcoal briquettes as they are not, in most cases pure charcoal. I did some research on this before starting my experiments with Terra Preta.

The composition of the briquettes vary from company to company, however most have a chemical ignition accelerator to ensure what the makers term as being a clean burn.

See earlier postings on this aspect by other contributors to the site, my own opinion is that if not making your own low temperature burn charcoal yourself then it is best to use lump charcoal.

Lump charcoal can be inoculated with any organic nutrient mixture of your choice. This is then mixed on a 1:2 basis with good home made organic compost.

It should be noted that the use of non-organic fertilisers either kill or denature the micro-organisms in the soil

I hope that this explanation helps

The mind is like a parachute its totally useless unless its open