Deparbnent of Botany, Institute of Biological Sciences, Federel University of Minas Gerais, Brazil.
The growth of Leucaena leucocephala (Lam) de Wit Inoculated with Rhizobium strain TAL 1145 and Mycorrhizal fungi was compared in, Atlantic forest soli (pH = 5.2) and eucalyptus forest soil (pH = 3.5) in a pOt experiment was conducted in a greenhouse. There were significant differences in plant biomass production between soils. Leucaena growth and nodulation were inhibited in soil under eucalyptus plantations. Double inoculation of rhizobia and mycorrhizal fungi was the best treatment compared with the single ones. The lime treatment of eucalyptus soil Increased the pH to 5.1 but did not Increase the dry mass or number of formed nodules. However, Rhizobium strain in culture media displayed tolerance to pH 5.1 and to high AI levels (50 μM). Low P in the presence of high AI was a severe stress to the growth of rhizobia. Nevertheless, lime treatment, phosphorus fertilization and mycorrhizal Inoculation did not Improve nodule formation in plants grown In eucalyptus soil.
