Soil scientists are tapping into the power of an ancient soil amendment.  Harold Johnson learned about biochar when he talked with John Bonitz about how his charcoal grill can help my plants. Listen on Tuesdays at 2 PM on WCOM 103.5 FM,  Saturdays at 8:00 AM on WDFC 101.7 FM (Greensboro), or anytime online at http://gettingdirtyradioshow.org/