Effects of supplementary nutrient in an aquaponic system for production of ornamental red tilapia Oreochromis Sp. and lettuce Lactuca sativa ...
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
International Journal of Ornamental Aquatics Research 1(1) 41-51 2018
Effects of supplementary nutrient in an aquaponic system for
production of ornamental red tilapia (Oreochromis Sp.) and
lettuce (Lactuca sativa var longifolia)
Rafiee Gh.R.1*; Ros Saad Ch.2; Kamarudin M.S.2; Ismail M.R.2;
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
Sijam K.2
Received: January 2018 Accepted: June 2018
Abstract
Effects of supplementary nutrient in the production of red tilapia (Oreochromis sp) and
Lettuce (Lactuca sativa var longifolia) evaluated in a representative water recirculating
aquaculture system. The nutrient solution supplemented was 25% level of (L25)
nutrient solution as medium used for aquaponic production of lettuce in the NFT
system (based on cooper’s formula). Thus, a completely randomized experimental
design conducted with two treatments in triplicates (Pl25 and PL0). Six black rectangular
tanks (114 x 86 x 100cm) used as fish culture tanks and each one equipped with three
hydroponic troughs. Each tank filled with 640 L of water and aerated continuously with
two circular air stones (3 L min-1) during the experiment. The system was efficiently
able to remove high rate of total ammonia -nitrogen (TAN) excreted by fish during the
experiment. The fish attained marketable size (200g) during a 110 –day period. Nutrient
supply had not significant effects (p>0.05) on growth of fish during experimental
period. The yields (Biomass/tank) of fish in treatments PL25 and Pl0 were 9.97 and
9.26 kg / tank, respectively. Three times cultivation and harvest of lettuce carried out
during the experimental period. At the first harvest, the yield (mean wet weight) of
lettuce showed significant (p0.05) and averaged 2112 and
1419 (Second harvest) and 1173 and 807 (Third harvest) for treatments PL25 and PL0,
respectively. It was recorded that red tilapia could tolerate 25% of nutrient solution,
used for aquaponic production of lettuce, and introduction of nutrient solution to the
culture system is necessary to get higher yield of lettuce at initiation of culture system.
Keywords: Nutrient solution, Aquaponic system, Lettuce, Red tilapia, Nitrification,
De-nitrification.
1-Department of Fishery and Environmental Sciences, Faculty of Natural Resources, University
of Tehran, P. O. Box: 31585-4314, Karaj, Iran
2-Department of Agrotechnology, Faculty of Agriculture, Universiti Putra Malaysia, Serdang,
Selangor, Malaysia
*
Corresponding author's Email: ghrafiee@ut.ac.ir
42 Rafiee et al., Effects of supplementary nutrient in the aquaponic system for production of …
Introduction production and environmental quality
Water re-circulating systems initiated problems adversely. Another way for
based on knowledge of fish preventing the accumulative frequency
requirements, physical and biological of nutrients throughout a fish culture
factors involving in the production of system is to link the plant for
fish in the culture system. The potential assimilating the major components
of all physical and biological aspects produced in intensified fish culture
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
and system performance in the removal systems, i. e., ammonia, nitrite, nitrate,
of accumulated N-compounds, then, other nutrients (macro and micro-
determine the capacity of each culture elements) which are responsible for
system. Total ammonia nitrogen eutrophication of aquatic environments.
(TAN), produced by fish, is the main In this respect, many research initiated
pollutant which must be removed from in both warm (Rakocy, 1994; Recovery
the culture system then fecal matter and research system) and moderate climates
remained food that all being derived (Lewis et al., 1978; Pierce, 1980;
due to feeding of the fish (Rafiee and Sutton et al., 1982; Rackocy, 2000;
Saad, 2005). During three last decades, Seawright, 1993) to utilize waste- water
various biological methods utilized to as solution nutrients for vegetable
treat water for reuse in intensified fish growth. As alkalinity declines in
culture system (Spotte, 1970; Rackocy, recirculating system as bicarbonate is
1989; Rafiee and Saad, 2005; Roosta consumed and acid is formed during
and Hamidpour, 2011). In general, nitrification, liming agents [CaCO3,
ammonia used by bacteria and it CaMg(CO3) 2, CaO, Ca(OH)2] are
converts to nitrite, then to nitrate added to maintain pH at 7.5 for
(Nitrification). In another process, integrated plant-fish culture (Rackocy
nitrate converted under anaerobic and Hargreave, 1993). Nutrient
condition to free nitrogen (N2) that the accumulation increases the conductivity
process called De-nitrification. In a of culture water as well. As a result,
recirculating aquaculture system, by however, nutrient accumulation is one
using bacterial bio-filters, the toxicity of the critical point but to maintain the
of ammonia removes but whenever the condition at steady state and desirable
low water exchange rates and high for fish and plant is more important.
feeding rates is aimed, for higher Because, it cannot be easy and the main
production of fish, the accumulation of goal, since dynamic of nutrients in
organic matter and consequent integrated system are complex and
mineralized nutrients productions some variables subjected to mineral
would be greater than nutrient removal manipulation. Therefore, the ability to
by bacterial and physical filters. control the nutrient composition of fish
Therefore, these matters have high and plant in culture water is limited,
potential to influence the fish especially at the initiation of culture
International Journal of Ornamental Aquatics Research 1(1) 2018 43
system while small amount of feed Universiti Putra Malaysia (UPM) under
added to the system. Some studies a tropical condition (water temperature
indicated that from fish culture system, 27-30C). A completely randomized
insufficient quantities of essential plant experimental design was conducted
nutrients obtained (MCMurtry et al., with two treatments in triplicates, a. the
1997; Parker et al., 1990; Rackocy et experimental integrated system with
al., 1993; Cerozi and Fitzsimmons, three lettuce troughs as hydroponic
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
2017). Thus, balancing the profile of compartment (P) without nutrient
nutrient in water at the tolerating ratios supply (PL0), b. with 25% of cooper’s
or levels for fish, plant and bacteria and formula (PL25) for hydroponic culture
achieving high production of fish and of lettuce (Cooper, 1987). The
plant is so important. In this regards, experimental unit was a black
the aim of this study was to investigate rectangular tank (114 × 86 × 100cm)
the effect of input-nutrient on fish and and three troughs (110 × 28 ×5 cm)
vegetable growth in a recirculating were utilized and fixed above each fish-
aquaculture system in order to using it rearing tank (20cm above the rearing
for ornamental fish culture. tank), An aquarium pump (Aquatic
pump model 1500, 16.5 Watt) was
Materials and methods positioned inside each rearing tank at
System and experimental design the corner for re-cycling the water
This study was conducted at the through the system. Water pumped from
Aquatic Resources Technology rearing tank to L-shaped pipe and under
Laboratory, Institute of Bioscience, the pressure of pump led to three
hydroponics troughs and returned to
rearing tank again (Fig. 1).
Figure 1: Schematic diagram of the system: integrated fish and plant co- culture with use of L-
shaped pipe.
44 Rafiee et al., Effects of supplementary nutrient in the aquaponic system for production of …
Water supply the end of horizontal part of the pipe for
Two days before acclimating the fish, possible cleaning.
each fish tank filled with 640 L of tap
water and aerated continuously with Feed and feeding
two circular air stones (3 L min-1). The fish fed a floating pellet diet,
Water supply had following containing 32% Protein (min), 6% Fat
characteristics: age tap water: pH=8.1; (max), 6% Fiber (max) and 11%
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
EC= 0.24m mhos; N=1.1mg L-1; moisture (max) that ordered from Car-
Mg=1.71 mg L-1. P=0.00031 mg L-1; gill Company, for grower of red tilapia.
Fe=0.0001 mg L-1; K=2.4 mg L-1; Mn
=0.003 mg L-1; Zn=0.01 mg L-1; Production of lettuce seedlings
Ca=23.2 mg L-1. Two weeks prior to experiment
The evapotranspiration and leaking commencement, for production of
loss of water compensated with tap lettuce seedling, seeds of lettuce sowed
water during the experiment. Prior to in some sheets of sponge (40×60 cm)
initiation the experiment, the fish already cut to small pieces (3 ×3cm).
acclimatized the system for one week. The seeds irrigated daily until
The EC of water in treatments with germinating, each newly seedling
nutrient supply adjusted at 0.65 ± 0.02 transferred to a small perforated plastic
mmhos cm-1, using supplementary cups and transferred to hydroponics
nutrient. Two stock solutions were troughs.
prepared, using below mineral salts:
Stock solution A: Ca (NO3) 2, 3009 g; Protocol
Fe -EDTA, 23g in 15 liter of tap water The experiment run on March 5, and
Stock solution B: KNO3, 1700g; terminated on 25 August (110 Days). At
MgSO4, 1539g; H2KPO4, 789g; the day of experiment commencement,
MnSO4, 18.3g; HBO3, 5.1g; ZnSO4, the 45 cups, each comprising a one-
1.3g in 15 liter of tap water. 800 ml week aged seedling of lettuce, placed
from each stock solution taken and into the holes of polystyrene sheets that
added in each experimental tank to get already fixed inside all NFT troughs.
25% of nutrient solution, based on Three times planting and harvesting of
hydroponic production of lettuce in lettuce were carried out during the
NFT system. experiment (averagely, with a five-week
L-shaped pipe utilized in all systems period). Each rearing tank stocked with
as a settling chamber of fecal mat (5 75 red tilapia juveniles with the average
inches diameter, 0.6-meter horizontal and standard length of 5.62±3.75 g and
length and 1.5-meter vertical length). 5.73 ± 1.41cm, respectively. The fish
Each pipe positioned in parallel beside fed twice a day ad libitum at 09.00 h
the rearing tank. A valve conducted to and at 15.00h.International Journal of Ornamental Aquatics Research 1(1) 2018 45
Water quality monitoring Results
Dissolved oxygen (DO) and water Fish production
temperature (T) in fish tanks measured The fish growth was not significantly
twice a week by YSI Model 57. Electro- different (p>0.05) between treatments
conductivity (EC) was determined at the end of experimental period. The
twice a week using EC meter model average biomass of fish was 9.97±2.41
HANA instrument conductivity meter and 9.26±1.34 kg in treatment PL25
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
HI 8033. The pH was determined using and PL0, respectively at the end of
Orion model 410A pH meter. Total experimental period (Table 1; Fig. 2).
ammonia (NH3+NH+4) and Nitrite- The rate of survival in treatment PL25
Nitrogen (NO2+) were measured (after was significantly lower (p46 Rafiee et al., Effects of supplementary nutrient in the aquaponic system for production of …
was significantly higher (p0.05) between
(p> 0.05) between treatments. These treatments. After two weeks, the
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
rates in treatments PL25 and PL0 were concentration of nitrite increased up to
averagely 2112±697 and1685±192 3 mg L-1 in both treatments. Within the
respectively for first and 1173±402, and last two weeks, an increase in nitrite
807±180g, respectively for third harvest concentrations recorded in both
(Fig. 3). treatments and reached to 4 mg L-1 (Fig.
4).
Figure 3: Mean yields of lettuce gained from
three times planting and
harvesting during the Figure 5: The Changes of Nitrite-N in
experimental period (veg. w. 1, 2, different treatments during the
3 = biomass of lettuce in first, experimental period.
second and third harvests in
different treatments).
Nitrate (NO3+)
With using nutrient solution in
treatment PL25 at the commencement of
experiment, concentration of nitrate
increased up to 75 mg L-1. After on
smart depletion of nitrate occurred in
treatments PL25. The nitrate
concentration ranged 0.023 to 6.39 mg
Figure 4: The changes of TA concentration L-1 at the end of experiment (Fig. 5).
in different treatments (in
rearing fish tanks) during .
experiment.
Water quality parameters Dissolved oxygen (DO), Temperature
Total ammonia (TA) (T), pH and EC
TA concentration in treatments DO did not show considerable
continuously increased and after five depletion in rearing tanks and at the
weeks reached to more than 10 mg L-1 bottom of L shaped pipe. DO ranged 6 -
(PL25). Afterward the concentration of 8.5 mg L-1 in rearing fish tanks. WaterInternational Journal of Ornamental Aquatics Research 1(1) 2018 47
temperature was between 27-30ºC
during the experimental period. The EC
rates in different time intervals (in
rearing tanks) showed significant
differences (p0.05) between
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
treatments. The EC of water constantly Figure 7: The pH changes in different
increased in both treatments and treatments during the
experimental period.
reached up to 0.86 and 0.85 mmhos cm-
1
in PL 25, PL0, respectively (Fig. 6). Discussion
In this study, with use of simple
feasibilities, a new design for
production of fish in integrated water
re-circulating fish culture system with
use of supplementary nutrient
introduced. The system demonstrated
that could successfully remove
increasingly accumulation of N-
Figure 6: Average changes of EC in different compounds through experimental
treatments during the experimental period. The result showed that seven
period.
weeks after starting the experiment,
systems were able to hold the
concentration of total ammonia-N
At the start of experiment, pH were
below the 48h LC50 2.5 mg L-1 reported
adjusted at 7.8 (mixed aged tap and
for Sarothrodon aurea (Redner and
well water, prior to adding nutrient).
Stilkney, 1979). The concentration of
When nutrient added to treatments
nitrite also averaged 3 mg L-1 (Fig. 4) at
PL25. It came down and reached to
the end of experiment that it was less
below 7. The sharp depletion of pH
than the threshold already reported in
recorded in all treatments during the
catfish, 96h mean tolerance of 7.5 mg
experiment and continuously showed a
L-1 (Sutton and Lewis, 1982). The
decrease. After 5 weeks pH reached to
concentration of nitrate in treatments
below six in both treatments, after that
with nutrient supply was 74 mg L-1 at
slowly increased and got to 6.5 in 8th
the start of experiment, afterward, smart
weeks. Afterward had fluctuation and
depletion of nitrate occurred in
ranged from 5.4 to 7.1 by the end of the
particular in treatments PL25. Nitrate
experiment (Fig. 7).
depletion probably was due to activities
of plants and bacteria in assimilation of
nitrate. Existence of nitrite in rearing48 Rafiee et al., Effects of supplementary nutrient in the aquaponic system for production of …
tanks also emphasized that the emphasis on permanent production of
nitrification and de-nitrification leafy vegetables for local and civil
activities occurred by bacteria during regions due to balancing the nutrient in
the experiment; However, at the start of different aquaponics design (Kyaw and
experiment there was not any Andrew, 2017). The growth of fish was
concentration of ammonia and nitrite in not significantly different between
water supply. At the first of the treatments, it accentuated that
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
experiment, lack of nutrient was supplementary nutrient had not
evidence in treatments without nutrient significantly negative effect on growth
supply because of unsuitable growth of of fish. The fish reached to marketable
vegetable. When water EC approached size (200 g) within 110 days. In a
to the level of 0.33 mmhos (after 40 natural condition at 23°C, tilapia
days), moderately growth of lettuce (Sarothrodon nilocticus) reaches to 200
occurred in comparison with the g weight within six months (Naegel,
nutrient supply system, meaning that 1977). However, it has been reported
standard Ec for introduction of that tilapia shows maturity after six
vegetable in integrated system could be months of age, but during this
0.33 mmhos, however profile of experiment some fish started displaying
nutrient must be considered for mating behaviors and color changes
standardizing the Ec. Concentration of when attained 100 g weight (after two
nutrient in water did not reach the months) and showed territorial
levels commonly utilized in commercial operations and attacked to each other,
production of vegetable in hydroponic this condition can be related to welfare
system, large amount of feed suggested condition of fish in the culture system.
approximately 8-10 kg/m3 must be used One of the most important points of this
to get suitable medium for culture of experiment was sharp depletion of pH,
most vegetable in hydroponic system from about 8 below 6 during the first
(Rackocy et al.,, 1993). It was resulted four weeks of experiment and below
that excretion of fish and bio- seven for next period, indicating
degradation of organic to inorganic reactions of De-nitrification by bacteria.
matter just provide moderate nutrients Depletion of pH had also observed
required for vegetable (lettuce) culture, already by other experimenter (Naegal,
emphasizing the effect of nutrient 1977; Rakocy et al., 1995; Rakocy,
solution either on growth of plant or 1989). Acidic conditions not only have
further removal of N-compounds. an important role in neutralizing the
Foliar use of nutrient demonstrated as toxicity of high concentration of
one of practical method to improve ammonia in rearing tank but also
nutrient deficiency in hydroponic part affecting solubility of some elements
of integrated system (Roosta and such as Fe (ferrous), Zn (Zinc) and
Hamidpour, 2011). Such a system evenInternational Journal of Ornamental Aquatics Research 1(1) 2018 49
Phosphorus (P) which can be more dominated in this study. Considering
available to plant. the fish yield of 31.5 kg/m2, for cat fish
Depletion of N-compounds in all (Lewis et al., 1978), 9.20 kg/m2 for Nile
treatments accentuated that the lettuce tilapia (Watten and Budch, 1984) and
and L- shaped pipe chamber efficiently 13.61-16.41 kg/m2 for present system.
operated as de-nitrification parts. Low The present system comprised
concentrations of ammonia, nitrite and vegetable plant and nutrient use, PL25,
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
nitrate and floating of fecal mat above showed capable for production of fish
the vertical part of the pipe indicated and vegetable in urban and local
the ability of horizontal part of L- regions in tropical condition, especially
shaped pipe in de-nitrification for ornamental plant and fish culture.
(Seawright, 1993). Since, de- Determining the roles of biological and
nitrification occurs under anaerobic physical compartments separately in
condition, high accumulation of waste assimilation of nutrient required for
fish inside the horizontal compartment future studies. Since, nutrient supply
of the L-shaped pipe probably prepared affects de-nitrification and nitrification
anaerobic condition for activity of de- bacteria (Austin and Austin, 1989). The
nitrificant bacteria. In fact, It can be impact of nutrient on activity of
said that this part of system operated bacteria and biodegradation of organic
similar to both nitrification and de- to inorganic matter also require further
nitrification bio-filters. These studies.
compartments separately utilized by
some scientists for production of fish References
and vegetable throughout water re- APHA (American Public Health
circulating system (Naegal, 1977; Association) American Water Works
Sutton, 1982; Lewis, 1978; Pierce, Association, and Pollution Control
1980; Rakocy, 1984; Wren, 1984; Federal (16th ed.), APHA,
Zweig, 1986; McMurtry et al., 1990; Washington, DC (1980), p. 1268
Rafiee et al., 2005). Austin, B. and Austin, D.A., 1989.
Comparing the result of this Bacterial Fish Pathogen Diseases in
experiment with other works, showed farmed and Wild Fish. Chi Chester:
that the efficiency of present system Ellis Harwood.
(PL25 and PL0) for high production of Cerozi, B.S. and Fitzsimmons, K.,
fish and vegetable and maintenance the 2017. Phosphorus dynamics
water quality parameters at optimum modeling and mass balance in an
ranges. If the land area surrounded for aquaponics system. Journal of
production of fish and vegetable Agricultural Systems, 153, 94-100.
considered, the usage of less space (1 Cooper, A., 1979. The ABC of NFT
m3 area) and high production of fish Grower book, London, 181P.
and vegetable within 15 weeks50 Rafiee et al., Effects of supplementary nutrient in the aquaponic system for production of …
Kyaw, T.Y. and Andrew, K. Ng., Proceedings of the World
2017. Smart aquaponics system for Mariculture Society, 11, 18-127.
urban farming. Journal of Energy Rafiee G.R., Saad, C.R., Kamarudin,
Procedia, 143, 342-347. M.S., Sijam, Ismail, K. and Yusop,
Lewis, W.M., Yoop, J.H., Schramm, M.R., 2002. A simple technical
H.L. and Brandenburg, A.M., feasibility for production of fish and
1978. Use of hydroponics to vegetable in an integrated
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
maintain water quality of recirculating system, Proceeding of
recirculated water in a fish culture Second International Conference on
system. Transactions of the Sustainable Agriculture for Food,
American Fisheries Society, 107(1), Energy and Industry, Beijing, 8-12
92-99. September 2002.
Mackay, K.P., and Tover, W., 1981. Rafiee G.R. and Saad, C.R., 2005.
An ecological approaches to water Nutrient cycle and sludge production
re-circulating for salmonids: during different stage of red tilapia
preliminary experience. (Oreochromis sp.) growth in a
Bioengineering symp. For fish recirculating aquaculture system.
culture (FCS publication No 1), 249- Journal of Aquaculture, 244,109-
258. 118.
MacMurtry, M.R., Nelson, P.V., Rakocy, J.E., 1989. Vegetable
Sanders, D.C. and Hodges, L., hydroponics and fish culture a
1990. Sand culture of vegetables productive interface. World
using recirculated aquacultural Aquaculture, 20 (3), 42-47.
effluents. Journal of Applied Rakocy, J.E., Hargreaves, J.A. and
Agricultural Research, 5(4), 280- Bailey, D.S., 1989. Effects of
284. hydroponic vegetable production on
Naegel, L.C.A., 1977. Combined water quality in a closed
production of fish and plants in re- recirculating system. Journal of
circulating water. Aquaculture, 10, Scientia Horticulture World
17-24. Aquaculture Society, (64A), 201.
Parker, D., Anouti, A. and Rakocy, J.E., 1989. Hydroponic lettuce
Dickenson, G., 1990. Experimental production in a recirculating fish
results integrated fish/plant culture system. Univ., pp. 4-10.
production system. Environ. Res. Virgin Islands Agriculture Exp.
Lab. Report no. ERL 90-34 Station, Island Perspect 3.
(unpubl.), 12P. Rakocy, J.E., 1994. Waste water
Pierce, B., 1980. Water reuses management in integrated
aquaculture systems in two green recirculating system. PP 75-80.
houses in northern Vermont. University of the Virgin Islands
Agricultural Experiment Station, RRInternational Journal of Ornamental Aquatics Research 1(1) 2018 51
2, Box 10,000 Kingshil, VI 00850, systems. In: Wang, J.K. (Ed.),
U,A. Bull. Nalt. Res. Inst. Agric, Techniques for Modern Aquaculture.
Suppl. 1. Proceedings of a Conference, 21-23
Rakocy, J.E., Hargreaves, J.A. and June (1993), Spokane, WA, pp.137-
Bailey, D.S., 1993. Nutrient 147.
accumulation in a recirculating Spotte, S.H., 1970. Fish and
aquaculture system integrated with invertebrate culture. Water
Downloaded from injoar.com at 16:19 +0430 on Monday May 20th 2019
hydroponic vegetable production. management in closed system. 145
112-136. in: Wang, J.K. (Ed.), pp. Wiley-Inter science, New York.
Techniques for Modern Aquaculture. Sutton, R.J. and Lewis, W.M., 1982.
Proceedings of a Conference, 21-23 Further observations on a fish
June 1993, Spokane, WA. production system that incorporates
Rakocy, J.E., 1995. The roles of plant hydroponically grown plants. Prog.
crop production in aqua cultural Fish-Cult., 44(1), 55-59.
waste water, Aqua cultural Watten, B.J. and Busch, R.L., 1984.
Engineering and waste management, Tropical production of Tilapia,
proceedings from the aquaculture Sarothrodon aurea, and Tomato,
Expo VIII and Aquaculture in the Lycopersicon esculentum, in small
Mid-Atlantic Conference, scale re-circulating water system.
Washington, D.C. June 24-28, 1995. Aquaculture, 41, 271- 283.
Rakocy, J.E., 2000. Integrating tilapia Wren, S.W., 1984. Comparison of
culture with vegetable hydroponics hydroponic crop production
in recirculating systems, Journal of techniques in a recirculating fish
World. Aquaculture society, 1(1), culture system. M.S. thesis, Texas
163-184. A&M University, College Station,
Render, B.D. and Stickney, R.R., TX, P: 66.Zar J. H. 1996.
1979. Acclimation to ammonia by Biostatistical analysis, 662P. 3rd ed.
Tilapia aurea. Transactions of the Prentice Hall, New Jersey.
American Fisheries Society, 108(4), Zimmerman, R., Iturriaga, R. and
383-388. Kiel, U.K., 1978. Simultaneous
Roosta, H.R. and Hamidpour, M., determination of the total number of
2011. Effect of foliar application of aquatic bacteria and the number
some macro and micro –nutrients on thereof involved in respiration
tomato plant in aquaponic and .American Society for Microbiology,
hydroponic systems. Journal of 36(6), 926-935.
Scientia Horticulturae, 129, 396- Zweig, R.D., 1986. An integrated fish
402. culture hydroponic vegetable
Seawright, D.E., 1993. A method for production system. pp: 34-40.
investigating nutrient dynamics in Aquaculture. Magazin., May/June.
integrated aquaculture, hydroponicsYou can also read
