Evaluating the agronomic benefits of biochar amended soils in an organic system : results from a field study at the UBC Farm, Vancouver Dennis, Jessica; Kou, Kelvin C.S.
Biochar is charcoal made from waste organic materials via pyrolysis that has the potential to improve crop productivity and sequester carbon when applied as a soil amendment. Increased crop yield is frequently reported from biochar-amended fields primarily in tropical and subtropical regions. The UBC research project investigated the effects of biochar as a soil amendment in an organic system located in a temperate climate. A field trial was undertaken at the UBC Farm in Vancouver, British Columbia to assess the impact of incorporating wood-derived biochar at a rate of 10t/ha into an arable loamy sand on beet yield. Beets were grown in 1m² x 19m² (3.5’ x 63') plots that were arranged randomly in blocks with three replicates for each type of the following four treatments: 1) biochar only, 2) compost only, 3) compost and biochar, 4) control (not amended). Total fresh biomass, root mass, shoot mass and number of plants were recorded and analyzed. Pre-and post-trial soil sampling and mid-season foliar sampling were carried out and assessed. The field study also explored the practical side of handling biochar on farm and experience with mechanical spreading is included alongside trial results. Biochar added at 10t/ha to organically managed loamy sand soil in a temperate climate did not impact beet yield, plant nutrient, or soil nutrient levels positively or negatively over one growing season. A slight increase in soil carbon in the biochar containing plots and a slight decrease in the plots without biochar was observed. A higher density of beets was found in the amended plots and it is hypothesized that biochar may have contributed to soil water retention resulting in higher germination or survival of beet seedlings. A second year of research will be carried out to consider the long term impacts of biochar. The initial findings from this trial suggest that the addition of biochar to already productive soils may not have the measureable impacts on yield that have been demonstrated in other regions and soils. Despite no clear yield benefits, no negative impacts were found in this trial, which indicates that biochar applications can still be a valuable soil carbon sequestration strategy in these soils. The potential for long-term benefits of biochar remain to be explored through continued research at UBC Farm.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada