cool, minerals are important. that biochar will just help to keep it there and keep it fertile. if you haven't added any yet, consider starting to add char powder to your worm bin with feedings(or compost pile). this way as you top dress the castings you will be little by little incorporating biological rich char to your topsoil. you can start out with regular old hardwood lump charcoal from the store if you cant go the homemade route. only thing is that stuff is kind of a pain to smash up. i prefer to use rice hull char or homemade char from chipped wood.
