Environmental Engineering Reference
In-Depth Information
reducing their growth or supplanting them entirely. This not only leads to a re-
duced biomass yield in most cases, it also produces lower quality or undesired
properties of the harvested biomass. Diseases and pests living on the photosynthe-
sis products and reserve substances generated by the plants have the same effect.
It depends on the harvesting process and technology which proportion and
which quality of biomass is available for energetic use. The right harvest time and
appropriate technique are particularly important factors for harvesting without
incurring major losses.
2.5.2 Supply characteristics
Spatial supply characteristics. The area-related supply characteristics of biomass
are defined by the combination of soil quality, precipitation level and distribution
plus the annual temperature curve. While precipitation and temperature only vary
to a limited extent across larger areas, the soil quality differs in very small spatial
dimensions. Therefore the biomass yields are characterised by tremendous varia-
tions throughout the world.
Very low
Low
Average
High
Very high
Fig. 2.51 Yield of winter wheat (left) and winter rape (right) exemplarily for Germany
Areas with a high level of biomass productivity are mostly characterised by
high-quality soils and sufficient precipitation amounts. In this respect it has to be
considered that different crops have varying requirements towards soil, tempera-
ture and precipitation conditions.
As an example Fig. 2.51 shows the yield level of winter wheat and rape exem-
plarily in the municipal and regional districts of Germany. If sandy soils coincide
Search WWH ::




Custom Search