Abstract:
Metal leachates from abandoned mine sites endanger plants, animals, and humans as
these enter the food chain. A technique to reduce availability of heavy metals to the
ecosystem was proposed. This made use of Flamingia sp., a forage legume, to facilitate
the removal of heavy metals from mine soil samples obtained from Paracale, Camarines
Nolle, Bicol Province Growth promotion and heavy metal-tolerance in plants were
assessed using varied combinations of soil supplements (consisting of lime, compost, and
mycorrhizal fungi). Experiments conducted were. (1) an experiment which determined
the combination of lime and compost concentrations that would raise acidic mine soil pH
from 4.5 to 6.5; (2) an experiment which determined the effects of commercialized and
indigenous mycorrhizal fungi inoculations on the growth of Flanungia sp. seedlings in
garden and mine soils; and (3) an experiment which determined the effects of lime,
compost, commercialized and indigenous mycorrhizal fungi inoculations, and their
combinations on the growth and heavy metal uptake of Flamingia sp. seedlings grown in
mine soils. A 0.01 gram of lime combined with 10 grams of compost raised acidic mine
soil pH from 4.5 to 6.5. Plants inoculated with commercialized mycorrhizal fungi
generally showed better growth than uninoculated plants in garden soil. Validated using
Duncaifs New Multiple Range Test (DMRT) at 0.1% level of significance and Least
Significant Difference (LSD) at p<0.05, results showed that plants under compost
treatments were taller (12.54cm) and had greater diy weights (1.48g/plant) when
compared with plants under noncompost treatments (8.16cm height and 0.76g/plant dry
weights). However, higher nodulation (22 nodules) and mycorrhizal infection (44.05%)
were observed among plants without compost treatments over those plants with compost
treatments (that is, at 8 nodules and 11.9%, respectively). Copper and cadmium
concentrations in leaves of Flamingia sp. were shown to be greatest in plants inoculated
with indigenous mycorrhizal fungi and lime but without compost treatment. Lead
concentration and copper, cadmium, and lead uptakes in leaves were also significant
among uninoculated plants with lime-compost treatment. Addition of lime and compost
significantly improved the height of Flamingia sp.
