2017 ASHS Annual Conference

Biochar application to agricultural soils is an emerging technology with potential for long-term carbon storage and enhancement of soil fertility. The effect of a biochar compost mixture, as compared to standard fertilizer, was assessed to determine the effects on the yield of cabbage (Brassica oleracea L. var. capitata L.), cv. Adaptor, over three years at two sites. Field trials were establish near Bradford (44°02'N 79°35'W) and Simcoe (42°51'N 80°16'W), in Ontario, Canada. A blend of 1:1 composted duck manure and biochar was applied at 6 (low) and 24 (high) tonnes ha^-1. This was compared to compost at the rate of 12 tonnes ha^-1, the rate applied with the high rate of biochar, to recommended NPK fertilizer, and to NPK fertilizer that delivered the same nutrients as the high rate of biochar (one site). None of the biochar alone, or compost treatments, increased yield compared to the non-amended check at either site. Treatments receiving the recommended rate of commercial fertilizer had the highest yields. In 2013, the biochar 24 tonne + NPK fertilizer resulted in higher total yield than the standard fertilizer at the Bradford site. Also in 2013, at the Simcoe site, the high rate of biochar resulted in higher total yield and weight per head, than fertilizer that delivered the same level of NPK nutrients. Application of biochar plus compost to these vegetable field sites in Ontario, Canada, did not result in a consistent increase in yield. Biochar may provide more benefits when applied to degraded soils.