Native warm season grasses are well-suited for adapting grazing systems in Tennessee to increasing floods and droughts caused by climate change. These deep-rooted, drought-resistant grasses can extend the grazing season and reduce reliance on stored forages. Including native grasses in 30% of pasture acres along with cool-season grasses spreads risk and improves livestock performance, land sustainability, and water quality. Research shows that native grasses yield well through summer, support strong cattle weight gains, and reduce nitrogen and phosphorus runoff into waterways. Outreach efforts aim to demonstrate these benefits to farmers and transition research findings to on-farm applications.

1. Native Warm Season Grasses
For Adapting to Climate
Change, Improving the
Sustainability of Grazing
Systems and Improving Water
Quality in Tennessee
Forbes Walker and Pat Keyser
University of Tennessee

2. Climate Change in
Tennessee
• More floods and more
droughts!
– Summer dry periods or
droughts: 2007, 2008, 2011,
2012, 2016
– Floods: 2010, 2017
2007
2011
2008
2012
2016

3. Pasture Animals in Tennessee
• All Cattle 1,830,000
• Horses 210,000
• Meat Goats 114,000
• Sheep 33,000
• Milk goats 8,600

4. Future Weather and Livestock?
• More floods
– Impact on hay production?
– Manure management? Manure storage?
– More hoof problems?
– More water quality impacts
• More summer dry periods or droughts
– Impact on pasture management?
– Impact on hay production and management?
– Summer feeding? More warm-season grasses?
– Manure management
– Watering cattle?

5. Pastures in Tennessee
• Dominated by cool season grasses
– Tall fescue
– Orchard grass
• The center of the Southeastern “fescue-belt”
• Decline in fescue quality
• Decline in number beef operations
– Recent droughts, herds culled
– Aging farmers
– 10% loss in acres in 5 years

6. Grazing in Tennessee

7. Extending the Grazing Season?
• More diverse forages = spread the risk!
• Less labor: grazing vs feeding
• Lower expenses; optimize profits?
• Better quality forage = better performance
• Better for the environment – manure
spread across field
• Weather is less of a concern
– What do you do in floods or droughts?

8. Diversifying the Forage Base
• Plant cool season and warm season
grasses in different fields
– 70% Cool season grasses: Tall Fescue,
Orchard grass
– 30% Warm season grasses: bermudagrass,
crabgrass, Native Warm Season Grasses
(Switchgrass, Big Bluestem, Little Bluestem,
Indiangrass, Eastern Gammagrass)

9. Center for Native Grassland
Management
• University of
Tennessee
• Started 2006
• Small plots
• Field scale feeding
trials
• On-farm
demonstrations

11. Complementing Cool-season System
with Warm-season Grasses
Orange Co., NC, June 10, 2014

12. Deeper Roots, Drought Resiliency and
Green Grass!
Aug 17, 2016
Sept 2, 2016

13. High Yielding
Data courtesy University of Kentucky
Extension

14. Forage May June July Aug
Switchgrass
2.83 1.92 1.48 0.75
Big blue/Indian 2.83 2.57 1.76 0.87
Strong Rates of Gain
(Sustained 90+ Days)
-Excellent tool for backgrounding/stockering steers,
heifer development, and grass-finished operations

15. • Summer forage is extremely important!
• Native grasses are a good option:
– very drought-tolerant
– low input perennials/profitable
– strong gains (>2.0 lb/day) + high yields
– relief from fescue toxicosis…
Native Warm Season Grasses

16. Next Steps
• Move from the research station to farmers
fields
– “Sticker shock”
• $200 per acre establishment
• No grazing first year
– Different management
– Survey of over 1,000 beef cattle farms
• Modeling of water quality and flooding
– SWAT modeling combined with climate changes
– Infiltration rates

17. Landuse in the South Fork of the
Obion River Watershed
Landuse Code “Actual” % Model %
Forest-Deciduous FRSD 40 46
Soybean SOYB 17 18
Pasture/Hayland PAST 15 16
Corn CORN 15 16
Wetlands-Forested WETF 6 4

18. South Fork Obion River Total Nitrogen
Loads With and Without Cover Crops
No Cover Crop Winter Wheat Cover Crop
TotalNitrogenRiverLoading,lbs/day
100
101
102
103
104
105
106
59%

19. South Fork Obion River Total
Phosphorus Loads With and Without
Cover Crops
No Cover Crop Winter Wheat Cover Crop
TotalPhosphorusLoading,kg/day
100
101
102
103
104
105
106
12%

20. Acknowledgements
This project was supported by Agriculture and Food Research Initiative
Competitive Award No. #2015-68007-23212 from the USDA National
Institute of Food and Agriculture.
• USDA NIFA: Water for Agriculture grant,
2014 to 2019
• Integrated Research, Extension and
Education
• University of Tennessee – Knoxville
• University of Memphis
• Tennessee Tech. University
• Middle Tennessee State University
• University of Tennessee - Martin