PRODUCTION OF ASSOCIATIONS OF GRASSES AND FORAGE LEGUMES TREATED WITH BACTERIAL INOCULANTS (Azotobacter spp. and Pseudomonas fluorescens)

Abstract

 Livestock production in Ecuador faces the challenge of sustainably improving pasture productivity to maintain sectoral economic viability in the face of fluctuating prices of meat and inputs such as fertilizers. The objective of this study was to evaluate the biomass production, bromatological concentration, and microbiological population of associations of fescue grass (Festuca arundinacea) and ryegrass (Lolium multiflorum) associated with red clover (Trifolium pratense) and alfalfa (Medicago sativa),and inoculated with plant growth-promoting rhizobacteria. The following bacterial inoculants were evaluated: Azotobacter chroococum, Azotobacter vinelandii, Azotobacter beijerinck, Pseudomonas fluorescens, and a control. The associations of grasses and legumes (2:2 ratio) were distributed in a block design with a subdivided plot arrangement and three replications. Harvest ages of 30 and 60 days after sowing (DDS) were allocated, and the following variables were evaluated: root length, root weight, protein concentration, ash, ether extract, fiber, and dry matter. It was found that the grass L. multiflorum associated with M. sativa and inoculated with + A. beijerinck had the highest dry biomass (2454.75 kg ha^-1) and the legume M. sativa associated with F. arundinacea and inoculated with A. vinelandii showed the highest dry biomass (1464.40 kg ha^-1) at 60 DDS. The highest concentrations of proteins with the inoculant A. beijerinki in the forages of F. arundinacea + T. pratense and L. multiflorum + T. pratense were 28.12% and 26.87%, respectively. It was evidenced that bacterial inoculants represent an environmentally friendly strategy to improve the morpho-productivity and nutritional quality of forage species.