Burning and grazing cool-season grasslands to promote native grass recruitment for agronomic, ecological, and social benefits

Project Overview

GNC07-076
Project Type: Graduate Student
Funds awarded in 2007: $9,972.00
Projected End Date: 12/31/2008
Grant Recipient: University of Wisconsin-Madison
Region: North Central
State: Wisconsin
Graduate Student:
Faculty Advisor:
Randall Jackson
University of Wisconsin-Madison

Annual Reports

Commodities

  • Agronomic: general hay and forage crops, grass (misc. perennial), hay

Practices

  • Animal Production: feed/forage, grazing management, grazing - rotational
  • Natural Resources/Environment: biodiversity
  • Production Systems: holistic management

    Abstract:

    We combined burning and rotational grazing to blend restoration and livestock production by promoting and maintaining native and non-native grass coexistence. Native grass tiller density increased under the burn and graze treatments, but not the burn-graze treatment. However, native grass tillers in 2007 were higher in the burn only than the graze only treatment. We found no loss to native grass tiller density when rotational grazing was applied after 2 years of grazing exclusion with burning. Our results suggest that the use of burning and grazing as a management tool for native grass persistence may be possible with deferred grazing during establishment phase.

    Introduction:

    The effects of burning on the tallgrass prairie has been widely studied but very little is known about burning and grazing cool-season pasture to promote reintroduced tallgrass prairie species. Prior to European settlement, prairie ecosystems dominated much of the upper Midwest, providing a foundation for efforts to restore patches of the tallgrass prairie in the Midwest (Brye et al. 2002a, Brye et al. 2002b).

    In Wisconsin about 850,000 ha of prairie existed at the time of European settlement (Curtis 1959) with about 8000 ha (<1%) remaining. While restoration and conservation efforts grow (Hobbs and Norton 1996, Hobbs and Harris 2001, Baer et al. 2003, Camill et al. 2004, Martin and Wilsey 2006), it is infeasible to convert most pastures to fully restored native flora because of their profitability for livestock feed when dominated by introduced, cool-season forage grasses and legumes. Ecological restoration in many ways means “starting over”, however, Williams et al. (2007) argue that it may be beneficial to keep the established vegetation and focus on enhancing species composition. We offer a compromise between complete restoration and complete eradication of native prairie by reintroducing native grasses within a cool-season forage matrix. The coexistence of cool-season and warm-season grass species has been shown to improve the distribution of forage production in pasture systems, especially during the hot, summer months when cool-season grass production is low (Anderson 2000). Belesky and Fedders (1995) found that when management was controlled there was no difference in productivity between warm-season and cool-season grasses. Warm-season grasses possess the C4 photosynthetic pathway, affording them greater water use efficiency (Lambers et al. 1998, Anderson 2000) and therefore less water stress during dry periods. In addition, warm-season grasses may improve supporting, regulating, and cultural ecosystem services. Examples include carbon sequestration, nutrient retention, and wildlife habitat. Fire management is considered a necessary tool in the establishment and restoration of the tallgrass prairie (Collins and Gibson 1990, Packard and Mutel 1997, Jackson 1999, Brye et al. 2002b, MacDonald et al. 2007). Fire influences both aboveground and belowground net primary productivity via reduced N mineralization and increased root production (Johnson and Matchett 2001) and can also promote plant community heterogeneity (Vermeire et al. 2004). While burning unequivocally favors warm-season grasses (MacDonald et al. 2007), cattle may be useful as a management tool in restoration because of their selective nature (Helzer and Steuter 2005). The establishment of warm-season grasses into cool-season pastures is difficult, especially when combining grazing and burning (Jackson 1999). Past research has shown that burning alone promoted greater warm-season grass establishment and root production than rotational grazing (Woodis 2008). We addressed the following question: Will warm-season grasses that have recruited into cool-season pastures increase or decrease under burn, burn-graze, or graze treatments? We hypothesized that native grass density would be greater under the burn treatment then the graze treatment, with the burn-graze treatment as an intermediate between burn and graze treatments. Our goal was to successfully combine conservation tools (burning) with agricultural management tools (rotational grazing) in order to promote native plant communities and increase forage production (i.e. aboveground and belowground).

    Project objectives:

    Results from this experiment will help determine whether burning and grazing can be combined for improved forage and root production (agronomic and ecological benefits). In addition, these practices will highlight farmers as land stewards, which promotes rural prosperity (social benefit).

    The expected short-term outcomes of this project are:
    1. Management techniques to promote the re-introduction and recruitment of warm season, native grasses into cool season, non-native grass pastures under grazing and burning practices.

    2. Quantification of root production and forage production under grazing, burning, and a combination of grazing and burning.

    The intermediate-term outcomes are:
    1. Increase farm participation in the conservation effort by promoting the re-establishment of native plant species.

    2. Burning for agricultural benefit should promote sustainable farming.

    The long-term outcomes of this project will help many stakeholders (researchers, farmers, policy makers, general public, conservationists) envision the integration of conservation efforts with farm management. This model should encourage adoption of new techniques and practices that improve production while enhancing the environment. These outcomes strongly fit the mission of NCR-SARE, which strengthens farmer profitability while improving the environment by supporting sustainable research.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.