Inoculation of marjoram with 15% and 30% aqueous
extracts of compost and/or biofertilizers have beneficial
effects on plant growth, essential oil content and dry matter
yield due to hormonal stimulation of root development and
by supplying combined nitrogen. The increase was more
pronounced mainly at 15% aqueous extracts of compost +
nitrogen fixers + B. circulans, whereas the effect was less
marked with nitrogen fixer strains, B. circulans or at high
levelof aqueous extractsof compost applied singly compared
with mineral fertilizers. At low level of aqueous extracts of
compost in the soil, simultaneous utilization of biologically
fixed nitrogen may be possible but at higher levels, the
potential for the nitrogen fixation may be decreased.