Andy Gordon, University of Guelph, agordon@uoguelph.ca (Presenter)
Naresh Thevathasan, University of Guelph, nthevath@uoguelph.ca


Willow was grown as a short-rotation woody crop (SRWC) in both a monocropped and intercropped setting, in southern Ontario, Canada. Willow clones tested included Salix dasyclados SV1, Salix miyabeana SX67 and Salix purpurea 9882-41. Willows were planted in 2006, and coppiced after 1 season; yield data were obtained annually over the next 3-years (the normal rotation). Although all 3 clones demonstrated higher yields in the intercropped plots, these differences were only statistically significant for SX-67. Biomass yield of this clone was ~ 6 odt/ha/y in the intercropped situation, but only slightly over 2 odt/ha/y in the monocropped situation. It is hypothesized that a modified microclimate in the intercropped situation may have led to these increased yields. Modelling with CENTURY indicated that, even in the monoculture situation, willow SRWC's could sustain soil organic matter levels on marginal sites over 68 years, the lifespan of three SRWC rotations. Intercropping systems are capable of contributing to sustainable landscapes, as a result of unique nutrient-cycling and carbon sequestration processes. Short-rotation willow appears to be another unique crop nicely adapted to the biophysical conditions present in the allies. The results are discussed in terms of economic, life-cycle, and biophysical research currently being undertaken on the feedstock-to-furnace bioenergy value chain being developed in southern Ontario, Canada.