Response of Alfalfa (Medicago sativa L.) to microbial inoculations with Rhizobium meliloti, Pseudomonas fluorescens and Glomus intraradices

Galina Petkova, Kostadinka Nedyalkova, Jonita Perfanova, Vesela Petrova

Abstract: The paper is aimed at establishing the effect of inoculation of alfalfa (Medicago sativa, L.) with N-fixing bacteria Rhizobium meliloti, mycorrhizal fungus Glomus intraradices and phosphate solubilizing bacterium Ps. fluorescens on the yield and N and P content of aboveground biomass. The plants were grown on Chromic Luvisol in a two-year field experiment under irrigation regime. Two cuts were harvested in the first year and four - in the second year. Positive effect of single and double microbial inoculations with Rh. meliloti, Ps. fluorescens and Gl. intraradices was established in both years. The largest increase in plant biomass yield and N uptake by the shoots was obtained with the single inoculation with Rh. meliloti 225 and mixed inoculation with Rh. meliloti 116 + Ps. fluorescens. The increases of alfalfa yield for these treatments were 29 and 34% for the first year and 32 and 27% for the second year respectively. The P uptake of aboveground biomass was the highest in the treatments with mixed inoculations of Rh. meliloti 116 with Ps. fluorescens or Gl. intraradices. The results obtained demonstrate the positive effect of microbial inoculations on the yield and nutrient uptake of alfalfa and could be of practical benefit for sustainable agricultural practices.

Keywords: alfalfa, symbiotic N-fixing bacteria; AM (Arbuscular mycorrhizal) fungus; nitrogen (N) and phosphorus (P) uptake; phosphate solubilizing bacteria; yield

Date published: 2021-06-30