Abstract:

A two-pronged approach is vital to reclamation success: (1) growing soil; and (2) eliminating the "weak link" factor. A focus upon "growing soil" as a strategy for establishing sustainable native plant growth on drastically disturbed (sterile) soils is proving to be both successful and consistent in its results. The strategy recognizes that the key to establishing native plant growth is to re-build sterile soils into vibrant organic matter, rich in living organisms. The objective is to fire up the natural cycling processes of the soil's "biological engine". Rather than merely growing plants per se, this strategy amounts to setting the stage for the natural re-establishment of mycorrhizal fungi, soil bacteria and other beneficial soil organisms necessary to grow early seral stage plants -- pioneer species that act as soil builders. This is accomplished through the incorporation of certain organic complexes of enzymes and bacteria, and protein-rich organic fiber nutrients into the seed bed. We are growing soil organisms first and foremost, in order to sustain vegetative cover on site through the stages of plant succession in our efforts to ultimately re-establish climax native plant species.

The rationale for pursuing the re-establishment of soil microbes is predicated upon the recognition that grass, forb and shrub species indigenous to the semiarid West are dependent upon mycorrhizal fungi associations to exist. The host plants supply the mycorrhizal fungi with simple carbohydrates (sugars) from photosynthesis. In return, the fungi, using energy derived from the host plant, extend hyphal strands (feeding tubes) far into the soil, increasing the surface area of roots to improve water and nutrient absorption for its host. This mutual symbiosis between the root systems of native plants and site specific fungi is behind what makes established native plants so "hardy" (so tolerant to low nutrient levels, drought, high soil temperatures, heavy metals, soil salinity, soil toxins, fungal and bacterial root pathogens, and parasitic nematodes), and yet so difficult to grow and keep growing.

Despite the existence of winning techniques and formulated materials to implement such "growing soil" efforts in harsh environments, true native plant establishment on sterile soils continues to be elusive owing to Nature's intolerance of, and the reclamation industry's tolerance of the "weak link" factor. The "weak link" factor is simply that one's level of plant establishment success will correspond to the weakest link in the process of design, supply, and field implementation. For a variety of reasons, the sabotaging influence of the weak link factor pervades the industry and is largely responsible for the industry's high level (80% +) of total seeding efforts that are ultimately judged "disappointing".