A former worker at a plant farm in East Texas who was from the mountains of Mexico showed me a process that he believed made for the best area for a garden. His suggestion:
Dig a hole about 4 foot down then fill with wood, burn it, enjoy the time, then when you go to put it out, put wood on the coals, cover with the dirt again, go to bed. Go back and dig out the dirt, then the charcoal. If it is all carbon then just add good, clean, ph balanced water to it and see if an oily sheen is on the top of the water surface, and how quickly it drains out. IF No sheen of rainbow and the water takes a good while to drain, then it is good to return the charcoal to the soaked area, add “ready made compost rich” (living) soil on top, (or breathable fabric bag full of living soil.) Then add your young plant or group of plants to the hole.
This method has proven to be a great success for non-row farming in raised bed type gardening.
There are several ways to add carbon to the soil, as well as many other things that could be added in this process, and it is interesting to note that Native Americans have been doing something similar for a very long time.