Utility of Plant Growth-Promoting Rhizobacteria for Sustainable Production of Bermudagrass Forage

Kayla N Sullins; S Leanne Dillard; David W Held; Elijah P Carroll

doi:10.3390/microorganisms11040863

Utility of Plant Growth-Promoting Rhizobacteria for Sustainable Production of Bermudagrass Forage

Microorganisms. 2023 Mar 28;11(4):863. doi: 10.3390/microorganisms11040863.

Authors

Kayla N Sullins¹, S Leanne Dillard², David W Held¹, Elijah P Carroll¹

Affiliations

¹ Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA.
² Department of Animal Sciences, Auburn University, 210 Upchurch Hall, Auburn, AL 36849, USA.

Abstract

A two-year study was conducted in bermudagrass hay fields in central Alabama to estimate the potential of plant growth-promoting rhizobacteria (PGPR) as a tool for sustainable agriculture in forage management. This study compared the effects of two treatments of PGPR, applied with and without lowered rates of nitrogen, to a full rate of nitrogen fertilizer in a hay production system. The PGPR treatments included a single-strain treatment of Paenibacillus riograndensis (DH44), and a blend including two Bacillus pumilus strains (AP7 and AP18) and a strain of Bacillus sphaericus (AP282). Data collection included estimates of forage biomass, forage quality, insect populations, soil mesofauna populations, and soil microbial respiration. Applications of PGPR with a half rate of fertilizer yielded similar forage biomass and quality results as that of a full rate of nitrogen. All PGPR treatments increased soil microbial respiration over time. Additionally, treatments containing Paenibacillus riograndensis positively influenced soil mesofauna populations. The results of this study indicated promising potential for PGPR applied with lowered nitrogen rates to reduce chemical inputs while maintaining yield and quality of forage.

Keywords: bermudagrass; biofertilization; biostimulant; forage biomass; forage quality; mesofauna; plant growth-promoting rhizobacteria (PGPR); soil health; sustainable agriculture.

Grants and funding

This project was provided by a Southern Sustainable Agriculture Research and Education Grant LS19-307 to SLD and DWH at Auburn University, and Agricultural Research Service, U.S. Department of Agriculture, under Agreement No. 58-6010-1-005. Additional support was provided by the Alabama Agricultural Experiment Station through Hatch funding from the National Institute of Food and Agriculture, U.S. Department of Agriculture.