Abstract
A pot experiment was conducted to evaluate the growth and metal accumulation in water spinach (Ipomoea aquatica) established
on a 30-year old active firing range soil amended with chicken manure (CM) and coconut tree sawdust (CTS) at application rates
of 0%, 1% and 3% (w/w). Both amendments increased biomass yield and reduced plant metal uptake. The bioconcentration
factor (BCF) and transportation factor (TF) values of the metals were in the order of Zn > Cu > Pb. The ammonium acetate
extractable metals in soil decreased significantly (p < 0.05) following CM and CTS treatments. It was estimated that the off-take
value of Zn could be reduced from 10.01 kg/ha (zero treatment) to 6.60 kg/ha (CM 3% w/w) and 3.17 kg/ha (CTS 3% w/w). No
toxicity symptoms were observed in water spinach over the pot experiment. Therefore, chicken manure and coconut tree sawdust
are two promising agents for immobilizing heavy metals in contaminated land.