A critical analysis of plant materials needed for soil bioengineering

The Natural Resources Conservation Service has added soil bioengineering techniques to the resource conservation practices we utilize. The NRCS Plant Materials Program has been evaluating plant materials for their utility in soil bioengineered systems. Two sources of materials currently are available: those harvested from local, presumably native stands, and those purposefully grown for meeting the need. Soil bioengineering techniques are valuable because they maximize root and stem mass on site in the shortest time possible. Engineers want to utilize systems that employ tested materials with known performance parameters so that risk of failure can be estimated. Plant-based systems inherently involve greater risk than do those using structural materials, due to weather, insect, and disease influences. Plant selection and nursery production provide opportunities for improving performance and generating risk assessment procedures. Plant materials harvested from untested local sources are useful in conservation work. These provide opportunity to increase species diversity, which is another way to reduce risk. However, selected and tested cultivars have performed very well, and have provided superior growth. This ability is retained even when dormant materials are held in storage for extended periods, then used on site after local materials have broken dormancy. This has served to lengthen the planting season. A plant materials database is being assembled for use by practitioners of soil bioengineering and biotechnical slope stabilization. Data from outside the NRCS is sought to expand the listing.