Plant growth-promoting rhizobacteria (PGPR) research has been ongoing at Auburn University for more than 40 years. However, the recent shift to a forage focus is a direct reflection of Alabama Cooperative Extension System professionals who want to make forage production more efficient and more cost effective for Alabama producers.

Leanne Dillard, an Alabama Extension forages specialist, said her work with PGPR is important to her because she is passionate about helping forage producers find a way to increase their profit margin. To help continue this work, the United States Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) recently awarded Dillard and a group of researchers a $750,000 grant to study PGPR.

“We are studying many aspects of forage production,” Dillard said. “Forage production really is environmentally sound, but production methods can always be improved.”

The group includes Dillard and three other Alabama Extension professionals—Kim Mullenix, a beef systems specialist, Adam Rabinowitz, an economist, and Ken Kelley, a farm and agribusiness regional agent. Additional Auburn University researchers include David Held, Zachary Noel, Alvaro Sanz and Brandon Smith. The team also includes partners from other institutions, including USDA-Agricultural Research Service and the University of Tennessee.

NIFA Grant

The project goal is to determine the efficacy of PGPR as a biostimulant for tall fescue and bermudagrass forage systems in the Southeast. Dillard said this approach is different than past research because it includes practical application studies, as well as a deep dive into forage production economics.

“We want to really revolutionize the way producers look at forage production,” Dillard said. “By conducting research that encompasses the entire process, we hope to be able to give farmers a stronghold in these continued times of market and fertilizer uncertainty.”

The team will sequence the genome of one PGPR strain and use this information for mass production of PGPR application material. Also, they will assess the effects of PGPR on tall fescue and bermudagrass drought tolerance under the greenhouse. In addition, the team will use a multistate field study to determine the usefulness of PGPR as a biostimulant for improving forage production and quality. Further analysis will help determine the economic impact of PGPR use on forage production in the Southeast.

Studying from all Angles

Mullenix said while the idea of PGPR research is not new, the full-circle approach to research is different than previous research undertakings.

“The way we think about farming is changing,” Mullenix said. “There may be a day when fertilizer is not as readily available as it is now. We are working to answer the question: how do we set up beef and forage producers for success in that kind of strenuous situation?”

Dillard and Mullenix agree that plant growth-promoting rhizobacteria technology is not a replacement for nitrogen applications, but the use of this technology may be a tool to remove producers’ input dependency.

“This research is so important because our job as Extension professionals is to share valuable information with our producers,” Mullenix said. “We are not working from scratch with this project, we are hoping to begin building something better from what already exists—exactly like producers would have to do.”

Financial Feasibility

Dillard said the one PGPR aspect that has not been previously studied is the financial feasibility side. Kelly and Rabinowitz will be collaborating with Dillard and Mullenix to answer the question all producers will inevitably have: “Can we afford it?”

Rabinowitz said one of the first steps to determining the answer is engaging with farmers to identify perceived barriers to technology implication on the farm.

“We are going to look at efficiency versus costs,” Rabinowitz said. “We are also going to look at producers’ practices and what could be done differently. Ultimately, we hope to provide an answer to show producers how this research-based information can help them move the productivity and profitability needle on their operation.”