Abstract:
Restoration of decommissioned Gold Mine Tailings (GMT) is an
environmental challenge. In this study, an attempt was made to evaluate the
combined application of organic and inorganic amendments' effects on the growth
and yield of lettuce in GMT. A Completely Randomized Design (CRD) with three
replications was used. For this, a greenhouse pot experiment with eight (8)
treatments mixed with tailings collected from Obuasi decommissioned mine site
was set up at the CSIR Soil Research Institute. Treatments used were; control, 5 t
ha-1 Rice Husk Biochar (RHB), 60 kg N-80 kg P2O5-80 kg K2O (100% NPK), 2.5
t ha-1 RHB + 30 kg N-40 kg P2O5-40 kg K2O (50% NPK), 5 t ha-1 Poultry Litter
Compost (PLC), 2.5 t ha-1 PLC + 30 kg N-40 kg P2O5-40 kg K2O (50% NPK), 2.5
t ha-1 RHB + 2.5 t ha-1 PLC and 2.5 t ha-1 RHB + 2.5 t ha-1 PLC + 30 kg N-40 kg
P2O5-40 kg K2O (50% NPK). At the end of the study, the highest lettuce yield
(433.9 kg ha-1) was found in 2.5 t ha−1 RHB + 50% NPK followed by the 2.5 t
ha−1 PLC+ 50% NPK (405.4 kg ha-1). There was no significant difference between
them. The lowest yield (144.9 kg ha-1) was recorded in the Control. Again,
application of amendments to the GMT showed a significant difference (P<0.05)
in pH, organic carbon, total nitrogen content, phosphorus, cation exchange
capacity (Ca, Mg, Na and K) of the tailings. The study revealed that the addition
of amendments could improve lettuce growth and yield parameters of lettuce and
also improve physical and chemical properties of GMT in the semi-deciduous
forest zone of Ghana.
