I have 2 questions. One article by a Russian scientist discusses the
effects of fertilization on microbial ecology. It suggests that high levels
of fertilization promote the growth of"toxigenic" microorganisms. At a
certain threshold which is very high for Mollisolls but much lower for
Spodisolls fertilization causes crop yield reduction due to the
phytotoxicity of microbial products. The organisms mentioned are mainly
fungi in the Penicillum and Asperigillus genera.
Is any familiar with this phenomena ?
A second article discusses N fixation in the gut of earthworms and
presents that the vermicomposting systems studied produced 40%+ N in
excess of the N
content of the organic materials fed to the earthworms. The worm species
was E. eugeniae and the substrate was Paspalum dilitatum grass. Is it
generally recognized that earthworms host substantial amounts
of N -fixation ?
U of MD, Agronomy