Richard Haard, Fourth Corner Nurseries, near Bellingham WA is using charcoal as a soil additive, apparently for at least the 2006 growing season. From the way he describes it, this bare-root nursery operation seems like one of the better places to see if and how much of a difference charcoal can make. He has lots of pictures of the process, including some observed positive effects on root growth. He is using charcoal as a carrier for inoculate as a matter of routine and has several future experiments under consideration:
- Rehabilitation of depleted soil: Bare-root production at the nursery is very hard on the soil and impact varies with the species grown, as revealed by differences in subsequent cover crop vigor. Using charcoal treatment plots and comparable control plots would be interesting.
- Improving nodule formation on Alnus rubra roots: Using charcoal to enhance performance of Frankia sp., an Alnus root nodule endophyte.
- Natural inoculation of bromide sterilized soil: Using a combination of charcoal, fertilizer and natural inoculum in an attempt to reverse stunting apparently due to soil sterilization.
Technorati tags: bio-char, terra preta