Back

Alternative Container Design for Large Acreage Revegetation

Background
Revegetation of arid lands disturbed by fire, or by cropping, mining, and other activities, represent a continuous and substantial expenditure by the responsible entities. Federal legislation such as the Surface Mining Control and Reclamation Act, the Conservation Reserve Program, and Comprehensive Environmental Response, Compensation, and Liability Act require the planting of native seed/seedlings and the expenditure of millions of dollars annually on sites that are highly disturbed or contaminated from activities such as mining, agriculture, industrial activities, and forest fires.

With regards to arid land shrubs, mechanical seeding and transplanting of nursery-grown plant materials compete directly for revegetation dollars but are not equal in their efficacy. Mechanical seeding is an inexpensive, but highly ineffective means of restoring arid land shrubs to disturbed sites. Mechanical seeding of arid land shrubs has proven largely ineffective for several reasons, including low seed efficiency, low seed availability, inability to effectively produce large quantities of seed from appropriate genotypes, and the increased hazard of noxious weeds introduction either naturally or from wildland seed collections. Transplanting of nursery propagated arid land shrubs, in contrast, negates many of these concerns and is highly successful but can be prohibitively expensive. If the cost of effective arid land planting stock can be substantially reduced, however, transplanting will likely become the revegetation method of choice on millions of acres of lands damaged by fire, mining, agricultural activities, and other disturbances.

The primary cause for this failure to produce cost-effective arid land planting stock is the lack of a container system designed specifically for arid land plant species. Current container systems have been designed for horticultural and forestry applications. In general, plant species grown for these applications are ecologically, morphologically, and physiologically different than arid land plant species grown for restoration projects. When these factors are taken into account, it is possible to design a short duration, high-density plant container system that will minimize nursery inputs without sacrificing infield survival. The benefit to be realized by clients is an inexpensive, highly adaptable source of arid lands planting stock that provides successful field establishment. A substantial potential market exists for a container plant system that produces low cost seedlings for arid lands restoration projects.

Bitterroot Restoration, Inc. in collaboration with U.S. Department of Agriculture, Agricultural Research Services received a Phase I U.S. Department of Agriculture Small Business Initiative Research grant to develop a low cost alternative container design for use in large-scale transplanting projects in arid lands. This project is being conducted at a number of locations across the western United States including the Idaho National Environmental Research Park at the INEEL.

Objectives
The technical objective addressed with fieldwork at the INEEL was to determine the percentage survival of sagebrush established in Booth Tubes versus other currently used forestry containers.

Accomplishments through 2002
Nine field study sites were established throughout the Western United States. The various sites represented different potential client types (i.e., mine industry, federal agency), different initial site conditions, and a broad geographic area. All sites experienced the continuing Western drought.

Each study site consisted of a completely randomized block of 200 replicates per treatment. Treatments were (1) 8 x 1 Booth Tube, (2) 164 cm3 (10 in3) Ray Leach Cone-tainer, (3) 65 cm3 (4 in3) Ray Leach Cone-tainer, (4) Ecopot-PS-315, (5) PaperPot-FS-315, and (6) Zipset Plant Band 1.25 x 6 in. Plant materials in all container types were produced under greenhouse conditions. Shipping and packing times for each container type were recorded. Field planting with hand planting tools occurred from mid-March through early May. Field planting times for each container type were recorded at each site. Field data (survival and height) collection occurred in August and September with one exception. The La Plata, New Mexico, site was dropped from the study because of complete mortality resulting from severe drought as reported by the project cooperator.

Analysis for the study consisted of calculating means for survival data at individual study sites. Planting rate and shipping rate data were compiled, averaged, and times normalized on a per thousand plant basis. Based upon this, estimated shipping and planting labor cost rates were applied to estimate cost efficiencies associated with each container type.

Results
Plant survival varied widely between sites and was highly dependent upon site moisture conditions. In general, the Bingham Canyon, Utah site was a dramatic success, while all other sites were judged as failures. Bingham Canyon received the highest precipitation amount (60 cm [19.7 in]) while La Plata Mine received the lowest precipitation (6.4 cm [2.5 in]). The Bingham Canyon Mine site experienced the most favorable moisture conditions resulting in excellent survival of Booth Tube containers (76 percent). At this site, the Booth Tube was equal to the Zipset for highest survival and exceeded all other containers. The high elevation of Bingham Canyon resulted in cooler temperatures, lower evapotranspiration, and higher rainfall than other sites. Areas with poor growing season precipitation and minimal subsoil moisture reserves fared much more poorly than Bingham Canyon Mine. Booth Tubes were marginally successful
(<10 percent survival) on sites receiving less than 30-cm (12-in.) of precipitation. North Antelope Coal Mine (10 percent) and INEEL (9 percent) had the next highest Booth Tube survival while all other sites experienced two percent or less Booth Tube survival. In contrast, the commercially available containers with more mature plant material experienced generally high survival on all sites with the exception of Hanford Reach National Wildlife Refuge and the Bureau of Land Management (BLM) Worland site. Both of these sites experienced less than 13-cm (5-in.) of precipitation during the October 2001 to September 2002 period.

Late frosts impacted Booth Tube seedlings at some sites. During the planting of the Caballo, North Antelope, and Worland-BLM sites, snow and freezing temperatures occurred for several days during and after planting. Black spots were noted on the dicots of Booth Tube seedlings, an indication of frost damage. In contrast, all of the commercial container material was dormant and immune to the effects of frost damage. Potential frost damage is a concern for the Booth Tube planting system. Previous research has indicated that winterfat (Ceratoides lanata), another dryland shrub, is highly tolerant of freezing temperatures during the dicot stage but damaged easily during the true leaf stage. An assumption for this study is that the same would be true of sagebrush. Further research to investigate frost tolerance of arid lands shrubs is proposed in Phase II.

Soil type may have also played a role in low survival of Booth Tube seedlings. Booth Tube containers removed from the INEEL site and the Natural Resource Conservation Service sites #1 and #2 were observed to have been plugged with fine soils. During hand-planting operations, planters tended to push Booth Tubes into the soils, thus creating a very dense plug of fine material at the lower end of the tube. This plug prevented root egress and likely contributed to the death of the seedling. In contrast, the Bingham Canyon site consisted of loose, highly drained gravels and consequently avoided the plugging problem. The plugging problem could easily be resolved by shortening the tube configuration to a 15-cm (6-in.) length that would allow for easier planting.

Despite overall poor survival, conditions at all sites were severely drought impacted and some success was achieved. The Bingham Canyon site represents what may be possible under more moderate growing conditions typical of the areas in which the seedlings were planted. The investigators do concede, however, that this container type may not be suitable for areas in which the mean average precipitation is less than 25-cm (10-in.) annually and sub-soil moisture is absent.

Plans for Continuation
Data on survivorship and growth rates will be collected again in the fall of 2003.

Investigators and Affiliations
Tim Meikle, Director of Research and Development, Bitterroot Restoration, Inc., Corvallis, MT

Funding Source
U.S. Department of Agriculture Small Business Initiative Research Grant

Back
 


Home | Background | Surveillance |  Land Management | Education | Research | Risk Assessment | Publications |  Links | Feedback | Opportunities