Effects of inoculation with rhizobia isolation and its interaction with basalt on Medicago polymorpha L. growth

Abstract

The aim of this study was to evaluate the effect of the inoculation of three rhizobia isolation of the strain collection from the chair of Agricultural Microbiology-UNNE, with and without the addition of basalt, on the growth of Medicago polymorpha. The 3x2 factorial experimental design was employed, with 6 treatments and 5 replicates, in a greenhouse: T1: A52 without basalt; T2: A52 with basalt; T3: A194 without basalt; T4: A194 with basalt; T5: A140 without basalt; T6: A140 with basalt. The data colleted was analyzed using ANOVA, with Fisher’s test (p<0,05) to check  means. It was possible to observe that  T6 and T4 treatments were superior than T2 by 37 % and 22% respectively, for the variable number of leaves per plant. T4 presented the highest number of branches per plant followed by T6, differing from T2 by 53% and 42% respectively. These differences are possibly due to the ability of these microorganisms to promote plant growth through the solubilization mechanism of rock dust that generates greater availability of nutrients. A52 developed in the opposite way, obtaining better results than the variables mentioned in the treatment without basalt (T1). There were no statistically significant differences among treatments for the variables root volume, root and shoot dry weight and biomass production per plant. Nodules were observed in one plant of T6 only. The rest of the treatments did not present nodules, possibly due to the high specificity of M. polymorpha or the type of soil used in the trial.