There have been substantial increments in the productivity of short rotation willow plantations in Sweden, especially on those well tended and with good management. Find the details in this new publication:
MOLA-YUDEGO B, 2010. Trends and productivity improvements from commercial willow plantations in Sweden during the period 1986–2000. Biomass and Bioenergy. doi:10.1016/j.biombioe.2010.09.004
Abstract
The production trends of commercial willow plantations for bioenergy in Southern and Central Sweden were studied for the period 1986–2000 based on harvest records of the first cutting cycle after the establishment of 1512 plantations. The trends were modelled by using a mixed model in order to include the variability of management options by the growers, which were grouped into four classes according to their performance. The spatial variability of the productivity is included using an agro-climatic index based on the official estimates of oat yields. Results of the study show average yield increments of 2.06 odt ha−1 yr−1 per decade. Areas with high productivity have significantly increased the yields of willow during the period studied, from 1.3 to 5.4 odt ha−1 yr−1. Regarding management, the best growers group shows a national average increment of 2.75 odt ha−1 yr−1 per decade, and the latest plantings reach an average of 6 odt ha−1 yr−1. This group is formed by farmers with previous experience growing willow, who tend to have significantly higher yields. In addition, experienced farmers increased their yields an average of 0.34 odt ha−1 yr−1 regardless of the group they were classified in. It is expected that future improvements of the willow varieties will result in a significant increase in the mean yields in the near future.
Keywords: Salix; Growth and yield; Bioenergy; Mixed models; Management
The production trends of commercial willow plantations for bioenergy in Southern and Central Sweden were studied for the period 1986–2000 based on harvest records of the first cutting cycle after the establishment of 1512 plantations. The trends were modelled by using a mixed model in order to include the variability of management options by the growers, which were grouped into four classes according to their performance. The spatial variability of the productivity is included using an agro-climatic index based on the official estimates of oat yields. Results of the study show average yield increments of 2.06 odt ha−1 yr−1 per decade. Areas with high productivity have significantly increased the yields of willow during the period studied, from 1.3 to 5.4 odt ha−1 yr−1. Regarding management, the best growers group shows a national average increment of 2.75 odt ha−1 yr−1 per decade, and the latest plantings reach an average of 6 odt ha−1 yr−1. This group is formed by farmers with previous experience growing willow, who tend to have significantly higher yields. In addition, experienced farmers increased their yields an average of 0.34 odt ha−1 yr−1 regardless of the group they were classified in. It is expected that future improvements of the willow varieties will result in a significant increase in the mean yields in the near future.
Keywords: Salix; Growth and yield; Bioenergy; Mixed models; Management
In the case of the best areas (using oat productivity as a proxy variable) the productivity of willow has increased significantly (see figure 6), especially if the management and tending of the plantations have been good (including proper weeding, site location and fertilization). This has been mostly due to better varieties as well as improved practices, and it seems that this trend will keep on going, although possibly not linearly.
For citing the figure: MOLA-YUDEGO B, 2010. Trends and productivity improvements from commercial willow plantations in Sweden during the period 1986–2000. Biomass and Bioenergy. doi:10.1016/j.biombioe.2010.09.004.
[Open access to pre-print]
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