Agriculture and Environment: Wood Pulp

Better Management Practices: Improve Harvesting Methods

High-technology harvesting equipment can increase the efficiency and productivity of harvest while leaving undergrowth and slash (harvesting residue) on the ground to protect the soil.

Using machines with tires rather than metal tracks tends to reduce soil compaction as well.

Leaving bark and trimmings in the field is much better for the environment. The bark and trimmings create a mulch that reduces soil erosion and builds soil organic matter. However, stripping the bark in the field costs more; it represents a 5.66% increase in the cost of forestry production compared to wood whose bark is removed at the factory.

In the case of Riocell S.A. in Brazil, bark removal results in an annual additional cost of about U.S. $1.5 million, or an increase of 1.23% in total production cost (WRI et al.1998). To evaluate the financial impact of debarking on the plantation, one would need to know whether leaving the bark in the plantation fields reduces the cost of nutrients or increases overall growth sufficiently to make up for the added cost. This is a relatively straightforward calculation for pulpwood plantations, but so far such calculations have not been done.

Calculating the costs and benefits of bark removal is further complicated by the fact that some processing plants use the removed bark as fuel. Vertically integrated companies must determine if the savings from the mulch that is left behind exceed the savings from using the material in the processing mill to reduce overall energy purchases.

Some vertically integrated companies produce up to 80% of their total energy needs by burning bark and other by-products. Other companies convert bark and other processing waste into marketable by-products. More than 99% of the solid wastes from processing in one mill in Brazil is used to make fertilizer or soil amendments, or added to cement (WRI et al. 1998).