That may
prove that composted pig slurry has a positive influence
on multiplication of plant growth-promoting rhizobacteria
(PGPR), among which one of the most important
groups is constituted by actinomycetes [1]. The value of
a rhizosphere effect for actinomycetes amounted to 4.8
when geranium was grown on the medium with compost
and to 2.7 when geranium cuttings were grown on the
medium alone (Fig. 3). This indicated a strong synergic
effect of compost and a rooted plant on the development
of actinomycetes within its rhizosphere