Un-inoculated single species hardwood Biochar. Mixed grade. A popular soil input used for its soil conditioning, water retention, and nutrient storage properties; due to its massively expanded surface area biochar provides great habitat for microbial colonization. Discovered in the Amazon many years ago biochar was a key ingredient of the 'Terra Preta' or Amazon dark soils. It was used to help create nutrient rich soils where naturally it was not. Our Birch Biochar is made from a single species of hardwood. This is so that we can ensure consistency in use rather than mixed species of hardwood, softwood, and green waste being sold currently. We believe this to be the only biochar available in the UK to offer guaranteed source material.