Biochar Q&A by Walt Benecki | Feb 4, 2016 | Organic Resource Center, Uncategorized | 0 comments Question: How many square feet of bed space will a one cubic foot bag of biochar cover? Answer: 10 to 20 square feet would be about right. Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment Name * Email * Website This site uses Akismet to reduce spam. Learn how your comment data is processed.