Annual and Perennial Crops for Bioenergy: Soil and Environmental Issues

Perennial and annual crops for bioenergy production are increasing. Much of
the biomass and oil used for energetic purpose come from cultivations where
bioenergy crops are grown with relatively high inputs. Large amounts of
nutrients are removed from the soil with the harvest; and inorganic fertilizers
lead to risks of soil water pollution. This chapter reviews the effect of bioenergy
crops cultivation on soil chemical, physical, and biological properties. Variation
is considerable, soil organic C decreased in most soils under conventional row
crops, also, soil N2O emissions are common as a result of the use of N fertilizers.
There is some evidence for high leaching losses of fertilizer nutrients and loss
of biodiversity. Soil erosion is a problem on newly planted land in many parts
of the world. It is concluded that annual and perennial bioenergy crops can
both substantially contribute to the supply of renewable energy, but an improved
crop management is needed to sustain and improve the resource base on which
production depends.