Jonathan Omar Cole Kubesch1,2, Lauryn Jansen1, Dillon P. Golding1,3,4, Makayla Bryant1, Frank Reith1,2, and Derek Hilfiker1,2
- Virginia Tech School of Plant and Environmental Sciences; Blacksburg, VA
- Country Home Farms; Pembroke, VA
- Virginia Tech Urban Horticulture Center; Blacksburg, VA
- Hoot Owl Hollow Farm, Woodlawn, VA
Today, most Upper South pastureland consists of tall fescue (Festuca arundinacea). Tall fescue grasslands suit cattle production needs for much of the year with few inputs and tolerate mismanagement more effectively than many other forage species (Kubesch et al., 2022a). However, tall fescue (TF) is limited in that the warm summer months are suboptimal for the cool-season grass, and the toxic endophyte in most tall fescue can lead to undesirable cattle effects. Cattle might have reduced performance in terms or gain, milk production, or reproduction, as well as elevated heat stress.
Native warm-season grasses (NWSGs) are warm-season grasses suited to producing forage during the heat of summer, when TF is not under optimal conditions for growth, which peaks in spring and fall. Examples of these species include big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), and Indiangrass (Sorghastrum nutans). Additionally, NWSGs can improve environmental outcomes over TF through wildlife benefits as well as improved drought resilience (Keyser et al., 2019; Keyser, 2021). Our position on the utilization of NWSGs in the Upper South for grazing is that NWSGs can complement existing TF grazing systems where management and infrastructure are available to transition between spatially separated TF and NWSG stands.
Spatially explicit TF and NWSG stands are requisite in order for the use of these respective species to be sustainable over a production lifecycle. Cool-season grasses outcompete warm-season grasses during the spring and fall, and the inverse occurs in the summer (Keyser, 2021). Portions of acreage for the TF and NWSG components of a grazing system have been used rather than a composition basis.
NWSG grass stands have been suggested to make up between 10-30% of Upper South farm acreage in a recent synthesis (Keyser, 2021). Given recent experimental work where heifers had the ability to select tall fescue or NWSG portions of a paddock over most of a grazing season, the 30% of acreage in NWSG seems more reasonable than the 10% value. However, given that converting from one forage to another forage results in 1+ year of lost forage production (Keyser, 2021), a piecemeal transition strategy like that suggested for organic forage production might be more practical (Kubesch et al., 2022b).
30% of farm acreage might be the long-term goal, however, that goal can be accommodated through converting smaller tracts over time. In a series of farm case studies, producers converted approximately 5-10% of their acreage to NWSG stands as trials for potential expansion (Virginia Cooperative Extension [Case studies]). Seeing as these conversions are already at smaller scales than what may be the long-term target, a piecemeal approach seems to be the most logical process. Conversions of select paddocks within grazing management units might also constrain the conversion process. Any forage establishment carries the risk of failure, and as such, establishing NWSGs during the conversion process can create additional risks (Kubesch et al., 2022b). In addition to the stand failing to result in enough viable plants for forage production, establishing stands can risk soil erosion, weed encroachment, nutrient leaching, water quality decline, and minor habitat loss for insects. The preference for perennial sods is in part to mitigate these environmental constraints, maintain forage production with minimal inputs, and to reduce establishment failure risk (Keyser, 2021; Case Studies; Kubesch et al., 2022b).
NWSGs can be seeded through no till methods, but the duration of the site prep, planting, and early establishment period can still result in negative externalities. In the Virginia case studies, NWSG stands were deemed as failures in 25% of mentioned attempts. Keyser (2021) builds economic budgets assuming a 10% failure rate curiously, but mentions an expected 15% failure rate when discussing establishment. Kubesch et al., (2022) builds a 15% failure rate into economic budgets concerning introduced forage species.
Spreading this establishment risk piecemeal through several conversion attempts might also hedge against the extreme outcomes. Encouragement might be found in that recent work regarding native grass and wildflower mixtures, with similar benefits of NWSG implementation (wildlife benefits, reduced soil erosion), suggests a failure rate of 32%. NWSG are easier to establish than complex native mixtures.
Given that most farms currently lack NWSG stands, the conversion process is a constraint as to their fit into TF grasslands and corresponding grazing systems. Establishing and managing NWSG stands can be difficult for producers trained around tall fescue’s establishment and care regimes (Keyser, 2021). For farms already struggling to match forage supply to cattle demand, reducing acreage for multiple grazing seasons is likely to prevent starting a conversion process. Conversely, understocked farms might not see the benefit of converting acreage to NWSG when forage supply regularly exceeds cattle demand. Similarly, NWSGs will not be suitable where infrastructure in the grazing system does not allow subdivision of the grazing management unit for both NWSG and transitions between NWSG-TF stands. Continued access to both TF and NWSG will result in preferential use of the NWSG stands. Farms that already have a spatially-separated perennial warm-season forage (e.g. bermudagrass) will be less likely to convert that acreage to another perennial warm-season forage.
Grazing systems that are economically more risk averse might need to rely on a subsidized program in order to use NWSGs, and those operations that might adopt NWSGs might not follow all best management practices necessary for some cost share programs (e.g. NRCS EQUIP). Compensation for planting NWSG stands often relies on stand evaluation that may or may not actually predict the long-term success of the stands. A wholly viable alternate perspective to using NWSGs might simply be that the grazing system already uses cool-season grasses other than tall fescue—such as orchardgrass (Dactylis glomerata) or smooth bromegrass (Bromus inermis) (e.g. Long, 1944)—that do not require toxicosis alleviation.
Forage systems without fescue toxicosis may or may not have reduced cattle performance due to limited forage production in the summer, but do not face the issues of heat stress coming from fescue toxicosis. Furthermore, farms with novel endophyte (E+) tall fescue might already avoid toxicosis and have stocking methods that do not stress these stands as much as traditional tall fescue stands. Farmers are less likely to benefit from NWSG where there are erosion concerns or neighbors hostile to native plantings.
Grazing systems that might be good fits for NWSG use would start with farms where the potential benefits of NWSG stands match producer goals in addition to forage and livestock production (Keyser et al., 2019). Conservation and multifunctional landscape objectives might justify NWSG stands for environmental value beyond forage production value (Case Studies). Farms with enough forage supply to meet cattle demand might seek NWSGs as a more consistent summer forage supply and a way to improve TF stands through rest (Case studies, Keyser, 2021).
Drought resilience is a key benefit of NWSG in this system. Grazing systems with growing livestock classes (e.g. heifer development) or fall calving herds would be especially suited for NWSG components. NWSG would provide heifer development in fall calving herds where weaned heifers could go onto NWSG for early weight gains. Farms where conversion tracts are smaller portions of the grazing system might also be a good fit because piecemeal conversion has only minor effects on system-wide productivity. Farms with areas suitable for conversion (ease of equipment access, low weed pressure, medium soil fertility, fencing) will be able to maintain the existing grazing system while making the conversion more feasible within a site.In the Virginia case studies, weed control was accomplished through subsequent clipping in many cases, though some producers also used herbicides to improve the NWSG stand.
Grazing systems where a two to three year establishment period is possible without critically throttling forage supply would be suitable for NWSGs. Rotationally stocked systems likely have the infrastructure to exclude livestock from NWSGs during establishment and to move cattle on and off NWSG areas for periods of stay will be good candidates for NWSG. Grazing systems with toxic endophyte tall fescue, a reliance on annual forages, sensitive classes of livestock (e.g. heifers and stockers), or economic liberties to test novel forages (e.g. Joel Salatin and ilk) would benefit from NWSG. Reducing fescue toxicosis in cattle classes can be seen as an improvement in animal welfare; similarly, strategies that avoid fescue toxicosis as well as increase summer forage production could improve cattle performance in these grazing systems. Grazing systems that are currently employing the best management practices for livestock and forages, effectively able to use cost sharing resources, and maintain strong marketing opportunities would also benefit from planting NWSG stands.
Acknowledgements
This publication was adapted from Dr. Gabriel Pent’s assigned written preliminary exam to Jonathan Kubesch. These considerations of native grasses were made possible with the support of the proprietors of Country Home Farms as well as Sarah Grace and Joseph Cole Kubesch.
References
Virginia Cooperative Extension case studies of Wilbanks Farm, Tuck Farms, and Swallow Hill Farm
Keyser, 2021. Native grass forages for the Eastern U.S. University of Tennessee.
Keyser et al., 2019. Eastern Grasslands: Conservation Challenges and Opportunities on Private Lands. https://wildlife.onlinelibrary.wiley.com/doi/epdf/10.1002/wsb.1000
Kubesch et al 2020. Simple strategies for profitable forage production. https://extension.tennessee.edu/publications/Documents/SP820.pdf
Kubesch et al., 2022a. Economic outcomes for transitioning to organic forage production. https://acsess.onlinelibrary.wiley.com/doi/full/10.1002/cft2.20178
Kubesch et al., 2022b. Transitional organic forage systems in the southeastern U.S.: Production and nutritive value. https://utbeef.tennessee.edu/wp-content/uploads/sites/127/2022/05/Transitional-Organic-Forage-Systems-in-the-Southeastern-U.S.-Production-and-Nutritive-Value.pdf
Long, 1944. Clinical Report & Operating Plan for Good Enough Farm, J. Omar Cole, Owner. The Modern Soil Conservation Service. W. Lafayette, Indiana.