The Evolving Understanding of Grassland Restoration Seeding Protocols

Grasslands provide many ecological services including reduction in soil erosion, improvement in soil and water quality, and increased wildlife habitat for certain specialized grassland species. Permanent grassland acreage has been declining in the United States since the late 1940’s. According to a study by the US Department of Agriculture (USDA)’s Economic Research Service, 60% of the land acreage in the contiguous US was grassland in 1948. By 2002, that figure had dropped to 44% (Wedin and Fales 2009) due to urban and suburban development, agriculture, and encroachment of woody vegetation. With this recognized loss of grassland and associated habitat, native grassland establishment has been promoted and cost-shared by the federal government in the last 25–30 years to recapture many of these ecological services associated with permanent grasslands.

Grassland restoration in the United States was accelerated through the passage of the 1985 Farm Bill which authorized the establishment of the Conservation Reserve Program (CRP). CRP is a voluntary program available to agricultural producers to help them use environmentally sensitive land to plant long-term, resource conserving covers such as native grasses to provide for improved wildlife habitat, control soil erosion, and to improve water quality. The 25-year legacy of CRP has resulted in over 32 million acres planted in permanent cover. Through successive Farm Bill authorizations, other USDA programs have been added to the portfolio such as the Wildlife Habitat Incentives Program (WHIP), Wetlands Reserve Program (WRP), Environmental Quality Incentives Program (EQIP), and the Conservation Security Program (CSP). These programs have encouraged landowners to establish native grasses by providing cost-share assistance for establishment. Additionally, a US Fish and Wildlife Service Program, “Partners for Wildlife,” complements many of the USDA programs on private working lands.

At the inception of the CRP, a huge demand was created for native grass seed. The USDA’s Natural Resources Conservation Service (NRCS) Plant Materials Program has been the primary conduit for getting native grass seed into the commercial market place for the USDA Conservation Programs. The major volume of native grass seed being produced commercially at the time in large quantities was in older established grass varieties. These were mostly developed from the 1940’s through the late 1970’s for livestock forage and erosion control. Some commonly available cultivars included Blackwell, Cave-in-Rock, and Kanlow switchgrass (Panicum virgatum) as well as Cheyenne, Tomahawk, and Nebraska 54 Indiangrass (Sorghastrum nutans). Available cultivars of bluestem varieties included Kaw and Niagara big bluestem (Andropogon gerardii) and Aldous and Camper little bluestem (Schizachyrium scoparium). Most of these cultivars were developed by the USDA-NRCS Plant Materials Program in cooperation with a land grant university and/or the USDA-Agricultural Research Service. A majority of these varieties are Midwestern in origin but have been shown to have a wide geographic and climatic adaptation.

Originally, seedings of native warm season grasses in the Northeastern and Middle Atlantic region of the country were originally looked upon with much skepticism by most landowners since they were accustomed to seeding introduced cool season turf and pasture grasses. In the early to mid 1990’s, native grass seed mixtures were extremely “heavy” on use of native warm season grasses and “light” on forbs (wildflowers and legumes) (Dickerson et al. 1997). Competitive, introduced legumes such as white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus) were included in some of the earlier seed mixtures for diversity. These species were readily available and inexpensive and were thought to compete well with the native grasses. However, these legumes proved to be too competitive resulting in poor and/or slower establishing grass stands. Also, a predominance of smooth seeded grasses such as switchgrass, deertongue (Dichanthelium clandestinum), coastal panicgrass (Panicum amarum var. amarulum) and the lovegrasses (Eragrostis spp.) were preferred since they could be seeded with conventional seeding equipment. However, as time went on, native grass drills, which handled long-awned or bearded seeds, such as the bluestems and Indiangrass, have become more commonplace and available for rent through local Conservation Districts or State and Federal wildlife management agencies or farm equipment rental companies (Figure 1). This has...