Past History 

The Rainwater Basin Wetland Management District has been seeding farmed uplands back to native warm season grasses for almost 30 years. Historically, seeding was done using a grass drill in the months of January, February, and March.  If possible, it was sown on the surface of a light snow covering. A high degree of success has been achieved with establishing these grasses and nearly all uplands seeded had a dominant stand within 3 to 5 years. During the first 2 to 3 years, an abundance of annual plants such as foxtail, marestail, and sunflowers dominate newly seeded fields--providing excellent habitat for pheasant, white-tailed deer, rabbits, and bird species that prefer weedy annual plants. During this establishment phase, thenative grasses and forbs develop deep root systems, but low amounts of foliage. By the end of the fifth year, the weedy annuals decrease while the planted species become dominant.

The major species seeded included big bluestem, Indian grass, little bluestem, switchgrass, and sideoats grama. Other native species included western wheatgrass, green needlegrass, and slender wheatgrass. Seeds were purchased from seed companies and were primarily improved varieties.

A few fields were seeded to mixtures designed to be more attractive to nesting waterfowl. These were comprised of non-native cool season grasses and legumes such as intermediate wheatgrass, smooth bromegrass, alfalfa, red clover, and yellow/white sweetclover. With time, these species either declined or increased in dominance--resulting in a poorly competitive plant community that allowed noxious weeds to become established.

During the past 20 years, some upland seedings included small amounts of native forbs; such as round head lespedeza, compass plant, leadplant or purple prairie clover. High seed costs and the species' slow rate of establishment discouraged extensive seeding.

Newly acquired wetlands were not seeded, but allowed to re-vegetate from the existing seed bank contained in the soil.  In 2000, we began to experiment with seeding certain wetland species, particularly sedges and wetland grasses. Certain species, especially some of the sedges, do not appear to return on their own and may have been eliminated from the available seed bank.

A few areas acquired by the Service had never been cultivated, but probably experience overgrazing and applications of herbicides.  Most of these sites currently contain an abundance of non-native species, such as Kentucky bluegrass and to a lesser extent smooth bromegrass. Dominant prairie forbs and grasses, such as leadplant, purple prairie clover, or porcupine grass and native wetland plants, such as western wheatgrass, marsh vetchling, or fog fruit can be found.

Current Management: High Diversity Seeding

The term high diversity seeding includes harvesting, processing and sowing large numbers of native species in an attempt to return the plant community as close as possible to its pre-cultivation condition. The term restoration has often been used to describe this same process, but restoring a grassland is not as simple as planting a few native plants.

Our objective is to manage uplands for warm season, grass-dominated (big bluestem in the eastern portion, and little bluestem in the western portion) plant communities with a diverse mix of other cool- and warm-season grasses,sedges, rushes, and broadleaf forbs.  Reference materials (see below) and examination of remnant native prairie tracts and wetlands were used to formulate a "watchlist" of plants.

During 1997, 1998, and 1999 Prairie-Plains Resource Institute conducted a large scale high diversity seeding on Springer WPA. The success of that seeding caused our office to expand high diversity seeding throughout the District.

It was determined that the wet meadow plant community was lacking and many wetlands would benefit from seeding of sedges, rushes, and wetland grasses. Disking of wetland areas was reduced, while burning and grazing was increased to encourage the establishment of native wetland species.  We expect the plant communities to recover from the seed bank in the soil when the hydrology and proper management is restored. A few select species, such as bur reed, may have been eliminated from the seed bank by the heavy waterfowl grazing pressure the wetlands receive.

Harvest

Harvesting begins in July with the gathering of sedges and rushes with the seed stripper.  The seed stripper is also used on western wheatgrass, sideoats grama, coreopsis, Indiangrass, big bluestem, little bluestem, deer vetch, and Illinois bundle flower. The staff and volunteers continue to hand strip seed throughout the season as species mature.  The harvest sites varies from year to year, depending on the weather. Our focus is to harvest the most seeds with the least amount of effort. The majority of the harvesting is done with the seed stripper head attached to the combine.

Seed Processing

Processing is required to some extent for all seeds. After harvest, the seeds must be dried. The seeds are usually spread out on cement floors and air dried for a few days. Drying is sped up by using two forced-air seed dryers. The hammer mill is used to break apart species that have large amounts of stems or seedheads needing to be broken apart.  No grass species are run through the mill.

The bulk of the mixing is completed in mid-November. It is done by placing the high volume grass seeds in piles surrounding the center of the floor and placing the smaller lots around the mixing area. The seed piles are then all mixed together once the right amount of each species is in the mix. Species with extremely small seeds are sprinkled into the mix. Seeds from various species are shared and traded with the Nature Conservancy and Prairie Plains Institute. A list of species in various mixes was developed.

Seeding

A Vicon spreader is used to broadcast seed during the winter months.  The spreader uses a PTO driven oscillating arm to spread and distribute the seed. The tractor can be operated at a higher speed, and it is nearly impossible to plug up the spreader. Almost no maintenance is needed. It is estimated that seeding requires about 12-14 bulk pounds per acre or about 5 to 7 PLS (pounds of live seed)/acre. The two main drawbacks with the Vicon spreader are not being able to see where seeded as well as the impact of the wind. Seeding over the snow improves visibility.  Seeding in two directions reduces the chance of leaving a bare patch.

Reference Material

Ecological Restoration of High-diversity Prairie PPRI’s Basic Guide by Bill Whitney Published in Prairie Plains Journal #13 pp. 39-56. 

The Tallgrass Restoration Handbook for Prairies Savannahs, and Woodlands by Steven Packard and Cornelia Mutel

The Prairie by J.E. Weaver and T.J. Fitzpatrick, Ecological Monographs, Volume 4, pages 109-295 (1934). Reprinted in 1980 by Prairie Plains Resource Institute. Aurora, NE.

North American Priarie by J.E. Weaver. Johnsen Publishing Company. Lincoln, NE.

Native Vegetation of Nebraska by J. E. Weaver. University of Nebraska Press. 1965

Flora of the Great Plains, ed. T. M. Barkley et. Al. (Great Plains Flora Association). University Press of Kansas, 1986.

Atlas of the Flora of the Great Plains, ed. William Barker et. al. (Great Plains Flora Association). Iowa State University Press. 1977.

A Garden of Wildflowers. Kansas Wildflower Society. 1992