B. Biro et al., SYMBIONT EFFECT OF RHIZOBIUM-BACTERIA AND VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI ON PISUM-SATIVUM IN RECULTIVATED MINE SPOILS, Geomicrobiology journal, 11(3-4), 1993, pp. 275-284
The frequency (F%) of spontaneous endomycorrhizal fungal infection (AM
F) and the root nodulation of Pisum sativum L, was studied after 8 and
15 years of recultivation in 4 soils (andesitic tuff yellow sand, yel
low clay, and grey clay) disturbed by mining activities. The effects o
f Rhizobium inoculation and the interaction of both microsymbionts wit
h plant production were also examined along with humus content and the
humus stability coefficient, in the following variations: control, NP
K fertilizer, NPK + lignite, NPK + straw and sewage sludge. Dump spoil
s originating from deep geological layers were poor in organic materia
ls. After 12 years of recultivation, the humus content increased signi
ficantly. No such increase was noted in grey clay and the natural, bro
wn forest soil used as an undisturbed (control) sample. The degradatio
n of soils by mining brings about a decrease in the rhizobial and myco
rrhizal population, so the number of spontaneous Rhizobium nodules is
relatively low and does not influence the yield of peas. Inoculation w
ith a selected, effective strain of Rhizobium leguminosarum bv. viceae
, however, enhanced dry matter production in these microbiologically d
egraded soils. Although the frequency of AMF infection was also higher
after rhizobial inoculation, no positive correlation was found betwee
n dry matter production of pens and the F% of AMF. Spoils treated with
lignite, straw, and sewage sludge had an especially high level of spo
ntaneous mycorrhizal populations, indicating that organic materials ha
d a favorable effect on the recultivation processes and fertility of m
ine spoils.