Evaluating Conversion of Exotic Grass Pastures to Native Warm-Season Grass: Profitability Analysis and Response of Wildlife and Imported Fire Ants

Project Overview

Project Type: Graduate Student
Funds awarded in 2012: $10,467.00
Projected End Date: 12/31/2014
Grant Recipient: Mississippi State University
Region: Southern
State: Mississippi
Graduate Student:
Major Professor:
Dr. Sam Riffell
Department of Wildlife, Fisheries & Aquaculture

Annual Reports


  • Animals: bovine


  • Animal Production: feed/forage, grazing management, range improvement
  • Farm Business Management: budgets/cost and returns, new enterprise development
  • Natural Resources/Environment: biodiversity, wildlife

    Proposal abstract:

    Native warm-season grass (NWSG) pastures may be a viable alternative to bermudagrass (Cynodon dactylon) for cattlemen in the Southern United States due to lower nitrogen fertilizer requirements and greater forage availability. NWSG may also provide nesting structure for breeding birds such as Dickcissels (Spiza americana) and decrease imported fire ant (Solenopsis spp.) density, an important agricultural pest. However, conversion to NWSG can be costly and require removing pastures from production for several years. My objectives are to estimate the establishment and opportunity cost of converting bermudagrass to NWSG by creating enterprise budgets with data from an operational, experimental grazing system. I will also perform sensitivity analyses on all parameters to identify effective routes for targeted subsidies or cost-share. I will quantify Dickcissel probability of nest survival and number of fledglings produced in bermudagrass and NWSG pastures to test whether NWSG conversion benefits wildlife. Finally, I will quantify imported fire ant mound abundance and activity in response to NWSG conversion, and evaluate costs of fire ant damage and pesticide treatment in a livestock operation.

    Project objectives from proposal:

    (1) Conduct a profitability analysis by creating enterprise budgets for establishment of NWSG and maintenance of grazing in bermudagrass and NWSG pastures;

    (2) Characterize response of Dickcissels (Spiza americana) to NWSG conversion by measuring daily nest survival rates and number of fledglings produced per nest in both systems. I will focus on Dickcissels because they are common in Mississippi, their populations are declining, and they are a suitable model organism for grassland avifauna in general because they are obligate grassland nesters;

    (3) Quantify imported fire ant response to NWSG conversion;

    (4) Create budgets based on mound densities measured in objective 3 to evaluate infestation and eradication costs of imported fire ants; and

    (5) Use sensitivity analyses on costs and cattle weight gain parameters to identify the most effective target for cost-share or subsidies to make NWSG conversion viable.

    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.