Non-Peer ReviewedNatural Resources Canada, along with a number of Canadian provinces, considers bioenergy to be a legitimate and sustainable source of energy that will constitute a significant portion of future energy production. Shrub willow (Salix spp.) is a proven viable purpose-grown bioenergy feedstock. The objective of this four-year study was to examine the cycling of nitrogen, phosphorus, potassium, and sulphur within several high density willow stands during the first rotation, in order to forecast the long-term sustainability of these woody crop plantations grown on numerous soil types in Saskatchewan. Soil and plant samples were collected throughout the rotation and analyzed for their nutrient content. The results of this study indicate that sites with relatively fertile soils are more capable of sustaining willow productivity for multiple rotations compared to sites with marginal soils, where supplemental fertility will be required to sustain long-term production levels. Ensuring optimal soil fertility will help promote the sustainability of these purpose-grown biomass energy plantations
