The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Monday, January 28, 2008 - 4:00 PM
Reestablishing Diverse Native Wyoming Big Sagebrush Communities: a Comparison of Seeding Equipment
Robert D. Cox, Rocky Mountain Research Station, USDA Forest Service, 322 E. Front St., Suite 401, Boise, ID 83702, Nancy L. Shaw, Rocky Mountain Research Station, US Forest Service, 322 E. Front St., Suite 401, Boise, ID 83702, and Mike Pellant, Great Basin Restoration Initiative, USDI Bureau of Land Management, 1837 S. Vinnell Way, Boise , Boise, ID 83709.
Across the Great Basin a cycle of cheatgrass invasion and increasing wildfire frequency is causing wide-scale losses of big sagebrush communities. In many areas active restoration is necessary to reestablish native species and maintain ecological integrity. However, restoring even a fraction of these important communities is technically challenging. Many species have small seeds that should be broadcast and pressed into the soil surface, while other species have large seeds that can be drilled. Seeding a diverse mix of such species, all with different seed sizes and germination requirements, requires the use of specialized equipment. We used a seed mix with four broadcast and six drilled species to study seedling emergence and establishment from a standard rangeland drill and a minimum-till Truax Roughrider drill. For broadcast seed, the rangeland drill’s seed tubes can be pulled from the disc assembly to allow seed to fall on the soil surface. The minimum-till drill is designed to broadcast and drill seeds in alternating rows. Emergence of all species was evaluated the spring following fall seeding. Drilled species showed similar emergence between the two drills. Broadcast species, however, emerged at a much higher density in areas seeded with the minimum-till drill. For example, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) averaged 1.2 seedlings/m2 and rubber rabbitbrush (Chrysothamnus nauseosus) had nearly 0.78 seedlings/m2 in areas seeded with the minimum till drill. These same species had only 0.27 and 0.32 seedlings/m2, respectively, in areas seeded with the rangeland drill. High-diversity seedmixes that include a variety of seed shapes and sizes may be more effectively seeded through the use of newer, minimum-till equipment. If higher emergence rates translate into higher rates of establishment, the use of such equipment may allow seeding at a lower rate, thus allowing more efficient use of restoration and rehabilitation resources by land managers.