| Author | Abdul Karim Gaffar |
| Call Number | AIT Diss. no.AE-95-01 |
| Subject(s) | Fish ponds
|
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AE-95-01 |
| Abstract | Several practical methods to mitigate problems of freshwater fishponds construction in acid sulfate soils were tested. A series of experiments was conducted on the AIT campus, Pathumthani Province, Thailand. The series consisted of a number treatments including. inundation, repeating inundation and drying, liming, addition of organic matter and fertilization. The effects of each treatment on soil deacidification, water quality and biological productivity were evaluated. Acidification—deacidification on the soil—water system was observed in laboratory and in field conditions. Experiment in polyethylene tanks show that 400 g of acid soil caused rapid acidification of 4 L of overlying water. Overlying water pH declined from 6.6 to 4.0, soil pH increased from 3.5 to 3.9 and soil potential acidity was slightly reduced from 24.67 cmol(+)/kg to 23.83 cmol(+)/kg after 6 weeks of inundation. In newly excavated ponds filled with surface water to 1 m depth. within 1 week water pH decreased from 7.2 to 4.7 and alkalinity was reduced from 85 to 8.34 mg CaCO)/L. After 2 months of submersion the redrying pond soil pH increased from 3.9 to 4.3 and potential acidity was reduced from 18.18 cmol(+)/kg to 14.20 cm0l(+>/kg. Without any treatment the pond soil will release a great amounts of acidic materials which were harmful to cultured fish. The effectiveness of leaching and flushing on removing acidic materials from pond soil was studied in 200 m" earthen ponds. Among various soil treatments. the repeated drying—flooding—flushing with harrowing was most effective as that removed potential acidity from 20.13 cmol(+l/kg to 10.87 cmol(+)/kg soil, and soil pH increased from 4.1 to 5.0) Leaching and flushing with a large amount of high alkaline water (1.000 m ) were able to reduced potential acidity in pond soils of 5 cm depth by 992.25 mol HY Organic matter enrichment has been reported to increases bottom soil pH through microbial activity, but in polyethylene tanks, with a soil pH of 3.9. addition of cellulose as organic matter had no significant effect on soil deacidification; soil pH increased from 3.5 to 3.9. In ponds the addition of 50 g/m /week chicken manure increased soil pH from 3.9 to 5.0. Liming has been described as a method for reclaiming acid sulfate soils. On a laboratory scale. addition of CaCO3 at a rate of 1.20 g/100 g soil effectively neutralized soil acidity. increasing soil pH from 3.5 to 7.4 and water pH from 6.6 to 8.2. In ponds. the effect of different liming rates on soil deacidification was significant on soil layers from O to 5 cm but it had an insignificant effect on the deeper soil layer. A liming rate of 475 g/mfl based on potential acidity in 5 cm soil depth, raised the soil pH ip its surficial layer from 4.9 to 7.4. Increasing the liming rates to 950 g/m‘ and 1.425 g/ml resulted in higher pH of 7.6 and 7.8, respectively. The effect of liming was not significant in soil depths of 5 — 15 cm, in which soil pH slightly increased from 3.% to 4.3. 4.3.and 4.5 in ponds with liming rates of 475 g, 950 g, and 1,425 g/m . respectively. ln manured ponds. a higher liming rate gave higher water pH and higher water alkalinity. and resulted in higher fish yield. Common carp stocked in control ponds without addition of lime or chicken manure had 100 % mortality, while in ponds receiving l.5 kg/m'of lime and fertilized with chicken manure of 50 g/m /week mortality was only 20 2. Only 3.3 % of common carp survived in ponds treated by lime alone. Liming was effective to neutralize soil acidity, but fertilization was essential to support fish growth. To increase plankton and fish production in neutralized soil of a fishpond constructed on acid sulfate soils. Three rates of fertilizer inputs were tested. Inorganic fertilizer, which was a combination of urea of 6 g/m /week and triple superphosphate (TSP) of 3.5 g/m /week gave a better effect on fish growth with net fish yield (NFYl of 7.53 kg/ha/day, whereas in ponds fertilized with chicken manure at SO g/m /week the NFX was 5.07 kg/ha/day, and in ponds fertilized with chicken manure at 75 g/m‘/week the NFY was 6.27 kg/ha/day. Phosphate sorption by pond soil has been reported to increase with increasing clay content, exchange acidity, exchangeable aluminum and iron.
Thus, the effect of different levels of phosphorus (P) input were tested on phytoplankton biomass in neutralized soils of fishpond built on acid sulfate soils. Increasing the level of P input up to 28 g TSP/m‘/month was linearly related to increased phytoplankton production. Mean chlorophyll a concentrations of 90.67. 46.63, 28.4O,an% 12.85 mg/m] were produced in ponds which received 28, 14, 7, and 3,5 g TSP/m /month. respectively. A minimum of 28 g TSPAT/month or 0.2 g Pflf/day with N:P ratio lal was recommended to produce mean chlorophyll a of about 100 mg/m¥ A management strategy is proposed based on this work. Newly excavated fishponds in acid sulfate soils of suffice tropaquepts require a sequence of soil and water treatments consisting of washing of three 3 or more cycles of drying—flooding—flushing, liming at a rate equivalent to the amount of soil potential acidity to 15 cm depth. and fertilizing with a relatively high P input > 0.2 g P/m‘/day with N:P ratio of lzl. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AE-95-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Lin, C. Kwei; |
| Examination Committee(s) | Edwards, Peter;Eiumnoh, Apisit,;Myers, J. K.;Philips, M. J.; |
| Scholarship Donor(s) | Government of Indonesia; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1995 |