Economic feasibility of biochar and agriculture coproduction from Canadian black spruce forest

Abstract

This study calculates the economic feasibility of converting biomass from black spruce forests into biochar and using it as soil amendment to grow potatoes (Solanum tuberosum L.) and beets (Beta vulgaris L.) to improve food availability in one of Canada's most consistently food insecure provinces. The trees were clear cut for the construction of the controversial Muskrat Falls hydroelectric dam and have been left to decay due to a lack of economically feasible processing options. A stochastic analysis conducted on a biochar production budget of a slow pyrolysis mobile biochar unit reveals fixed and variable cost estimates of $505.14 Mg−1 and $499.13 Mg−1, respectively. Applying the biochar as a soil amendment for local beet or potato production makes the biochar venture profitable. Beet field trial data from the study region using 10 t C biochar application rates increases beet yield from 2.9 Mg/ha to 11.4 Mg/ha with a midline increase of 5.59 Mg/ha. A stochastic analysis with variable prices and yields shows a 0.99 probability of biochar production being profitable when applied to beets at the midline production rate, with an average annualized net return over variable costs of $4,953 ha−1, and maximum annualized net return of $11,288 ha−1, over variable costs. Potato production yields average annualized net returns of $965.48 ha−1 over variable costs, but with much more downside risk, considering the minimum annualized net return of −$318.82 ha−1 over variable costs. Biochar application covers average total costs for beets but not potatoes. Using biochar from forest biomass as a soil amendment presents an opportunity to create a local market for biochar in a remote area of Canada, where biochar may be used as an experimental soil amendment to improve food security.