འོད་བསྒྲུབས་གི་གི་མེ་ཏོག་ནས་བིའོ་སྐྱར་བྱེད། — ཀར་བོན་གི་སྲོག་གི་འབྲེལ་བ་ཚུགས་གུབ་ཆོག

Biochar is charcoal produced specifically for soil amendment rather than fuel. When agricultural waste (wood chips, corn stalks, nut shells, prunings) is heated in the absence of oxygen (pyrolysis), the volatile organic compounds burn off as gas, leaving behind a porous carbon skeleton that is extraordinarily stable — biochar persists in soil for hundreds to thousands of years, effectively locking atmospheric carbon into a solid form.

The concept is ancient. The terra preta (dark earth) soils of the Amazon basin, created by indigenous peoples over 2,500 years ago, still contain abundant charcoal that continues to improve soil fertility today. Modern biochar research rediscovered this practice and demonstrated that biochar improves soil water retention, nutrient holding capacity, microbial habitat, and crop yields — while simultaneously sequestering carbon.

Unlike industrial carbon capture, biochar can be made by anyone with agricultural waste and a simple kiln. The process converts a disposal problem (crop residues that would otherwise decompose and release CO₂) into a permanent soil improvement. Each kilogram of biochar sequesters approximately 2.5-3 kg of CO₂ equivalent.