EFFECT OF DIFFERENT REMEDIATION TECHNIQUES AND DOSAGES OF PHOSPHORUS FERTILIZER ON SOIL QUALITY AND KLEKAP PRODUCTION IN ACID SULFATE SOIL AFFECTED AQUACULTURE PONDS
Abstract: Acid sulfate soils
(ASS) contain sufficient pyrite which, when oxidised following excavation for
brackishwater aquaculture ponds, will generate acid and mobilise toxic metals.
Production in affected ponds can be low due to poor growth of shrimp and fish,
mass mortalities of stock and low plankton blooms. The resultant low soil pH
can also cause poor klekap production due to the retention of phosphorus associated
with elevated concentrations of Fe and Al in the pond soils. A series of
experiments was conducted to determine the effects of different soil
amelioration techniques and dosage of phosphorus (P) on soil and klekap
production under laboratory conditions. The treatments consisted of two
factors. The first factor tested was different techniques for ASS improvement
(non-improvement, improvement through liming and improvement through
remediation involving forced oxidation of pyrite, flooding and flushing of
oxidation products). The second factor tested was phosphorus dosages, that is,
with phosphorus and without phosphorus-based fertilizer. Each treatment had
three replications. The experiment showed that liming and remediation had the
same effect on several soil variables; they raised the soi pH (pHF, pHFOX,
pHKCl) and decreased SPOS, Fe and Al. Remediation of ASS decreased retention of
P and increased available-P of soil, whereas liming did not show a significant
effect on retention of P and available-P in the doses used for this experiment.
The interaction between the different soil improvement techniques and
phosphorus fertilising showed a significant effect on klekap production with
the highest klekap production of 23.21 mg/cm2 found in remediated soil and with
a phosphorus fertiliser dosage of 75 kg/ha.
Keywords: remediation;
phosphorus; acid sulfate soil; klekap
Author: Akhmad Mustafa,
Jesmond Sammut
Journal Code: jpperikanangg070023
