biochar is the best, stable carbon in the soil. it works very well and enhances compost. compost by itself can degrade and decompose, releasing carbon in atmosphere. biochar slows down decomposition and improves the carbon for carbon cycle. it improves fertility and as time goes by, it keeps getting better.

charcoal has amazing capacity to absorb, including pollutants. this property allows charcoal to hold good bit of moisture.

Indigenous Mound Builders in Uruguay