Handling a willow bundle. Though materials are typically inexpensive or even free for the taking, soil bioengineering projects can be quite labour intensive.
In central Europe, soil bioengineering is relatively common compared to North America, though labour is roughly as expensive in Europe as it is here. This is because there they have an established tradition using these techniques for civic works projects, like roads, that goes back for hundreds of years. This is detailed in the history section of the reference mentioned previously. Like in the developing world, the savings which come from using locally available materials provides an economic incentive, that has helped to buffer against higher labour costs in Europe. A particular surge in such projects occurred in the 1930's during the Great Depression when labour was cheap.
Soil Bioengineering in North America is uncommon, but after many years of being overlooked, this is slowly begining to change. Instead of traditions serving to promote use of these techniques like in Europe, North American traditions have discouraged use of soil bioengineering. This is because of the North American focus on industrial "progress and development". Techniques using plants have been perceived as less sophisticated than those using concrete and steel.
Other factors that have discouraged the use of bioengineering techniques in North America include timing, logistics, and imagination. The effect on timing is that so called "hard" engineering solutions can typically be constructed more quickly (due to prefabrication) than can soil bioengineering. Also these are not constrained by the time of year, while soil bioengineering is best done in the fall and winter. Logistics comes in both getting approval of and financing for a project. Lack of familiarity of officials can work against receiving either a permit or funding. Additionally, labour costs can drive up the funds needed. And finally, in terms of imagination, most engineers understand cement better than they do plants, a bias which influences not only those approving a project, but the designers as well.
However, attitudes are changing, as more people come to understand the range of options avialble to them. Constraints on such projects, such as labour are not always as severe as one might think. For example, the manpower required can often be reduced by use of the same heavy machinery that makes conventional cement and steel projects possible (photo at right). Soil bioengineering is becoming recognized as another tool managers can work with.
Machine backfilling live soft gabions along a road cut.