Forced aeration composing of coniferous bark

A forced aeration system of composting was used to accelerate the decomposition of 14m3 piles of Sitka spruce bark (Picea sitchensis) for 1 month. The aeration system was similar to the Rutgers system except that greater aeration was used in the first 3 days of composting. Bioassays with tomato plants (Solanum lycopersicum) growing on such composted bark suggested that the phytotoxicity of raw bark was reduced by this process. The optimal conditions for decomposition were composting temperatures below 60°C, urea supplementation and milled bark.