Table 3 shows the ash content, ash softening temperature,
and calorific value of the wood for the tree species and clones
under study. The calorific value in terms of energy content
per mass unit was not significantly different between tree
species. However, due to the high wood density of R. pseudoacacia,
the calorific value expressed in terms of MJ per
cubic meter of wood chips (Table 3) is significantly higher
for R. pseudoacacia than for poplars and willow. This will be
economically relevante if storage or transport capacity is a
limiting factor. Based on the annual productivity of the second
3-year-rotation period and, taking into consideration the
survival rate the annual energy productivity of R. pseudoacacia
is at least more than three times higher than any other
tree species under study. A further advantage refers to the
very low ash content of R. pseudoacacia of about 1.5%, which
makes the wood highly suitable for combustion processes.
However, the melting behaviour reflected by the ash soft-Fig. 5 – (a) Yield of M. sativa on the Lusatian study site as a
function of the distance to the R. pseudoacacia hedgerow.
Significant differences between yields from different
distances to the tree hedgerow are marked by an asterisk.
(b) Yield of M. sativa on the Helmstedt study site as a
function of soil amendments.This will be
economically relevante if storage or transport capacity is a
limiting factor. Based on the annual productivity of the second
3-year-rotation period and, taking into consideration the
survival rate the annual energy productivity of R. pseudoacacia
is at least more than three times higher than any other
tree species under study.