Nutrition of Hybrid Willows for Bio-fuel Production
Seven different clones of willow grown as a potential bio-fuel crop were evaluated in their response to irrigation and N, P, K and S fertilization. After three growing seasons, prior to harvesting the plots for biomass measurements, seven stems per plot were be sampled and analyzed for N, P, Ca, Mg, Al, Fe, Mn, Cu, Zn, B, and Na concentrations. As well residual nutrient concentrations in the soil down to 60 cm (24 in) were assessed.
IPNI-2010-CAN-SK42
23 Feb 2011
2010 Annual Interpretive Summary
Willow Biomass Quality for Bioenergy and Bioproduct Applications, 2010
Growing willow as a renewable dedicated bioenergy and bioproduct feedstock is advantageous for a number of reasons, such as its naturally fast growth rate, along with important environmental benefits like providing a much cleaner energy source relative to fossil fuels. The majority of research to date has focused on the quality of willow biomass for bioenergy conversion and increasing plantation productivity through cultural practices. However, no one has investigated the effects of different agronomic practices on the wood quality of willow biomass for its different potential end uses. The potential exists, therefore, to not only increase plantation productivity through irrigation and fertilization, but also to accentuate favourable biomass quality characteristics through optimizing soil moisture and nutrient availability under an intensive management regime.
The study is being carried out in the existing Canadian Forest Service 2-year-old hybrid willow plantation, located in Saskatoon, Saskatchewan. The plantation is a clonal trial with seven different clones of willow. Three different rates of both irrigation and fertilizer treatments were imposed on each bed. The three irrigation treatments consist of either no additional water added above rainfall or drip irrigation used to maintain soil moisture at 75% (half water) or 100% (full water) field capacity, measured using soil moisture probes installed within each plot. The three fertilization treatments include no fertilizer or fertilizer applied once annually over the 3-year rotation, either at the recommended rate (Fert Treatment #1) or 2x the recommended rate (Fert Treatment #2). The recommended rate consists of a balanced fertilizer blend of 100:30:80:50 (N:P:K:S), which is intended to not only match hybrid willow growth requirements, but also replenish nutrients exported when harvesting willow with annual biomass production of 15 to 22 t/ha. The 2x recommended rate is intended to test the upper limit of willow growth response to added fertilizer. Analytical laboratory work is on-going and results will be completed in early 2011, with a final report being prepared in later 2011. SK-42