1. Don’t apply bulk biochar to your soil in one large load.
2. Don’t use raw, uncharged biochar
3. Don’t add sterile, uninoculated biochar with only a tad of microbial life.
4. Don’t combine biochar with synthetic salt fertilizers, tillage and other antibiotic practices.
Biochar is all about the microbes. Do everything to keep the microbial population expanding and diversifying. Biochar aids in these practices, and then soil productivity increases. It increases not because of the biochar itself, but because the biochar improves the quantity and quality of microbes.
For backyard composting, biochar should be added to the compost bins where it can absorb and sponsor microbial activities, and then be transferred to the soil.
Biochar has additional properties regarding toxicity and water holding capacity, but must be managed in different ways to expand on those benefits.