Vegetable production through Aquaponics

1. WELCOME
TO
P. G. SEMINAR SERIES
2019-20

2. Vegetable production through Aquaponics

3. Content
Introduction
Why it is better over other system?
Basic biological components
Balancing the aquaponics system
Structural components
Designs of aquaponics
Applications of aquaponics
Review of literature
Challenges and opportunities
Conclusion

4. Aquaculture
Hydroponics
Aquaponics
Aquaponics
1

5.  Aquaponics is the “Integration of Hydroponic
plant production into Recirculating fish
aquaculture systems” (Somerville et al., 2014).
 It is “Symbiotic cultivation of plants and aquatic
animals in a balanced recirculating environment”.
 Symbiotic relationship is that the fish provides
nitrogenous wastes (i.e. Ammonia ), which serves
as a nutrient for plants (i.e. Nitrates) and the plant
remove the nitrogenous compounds thereby
cleaning the water for the fish.
Introduction
2

6. Fish
Fish
excreta
Reuse
of
water Schematic
representation
of Aquaponics
system
3
Fish
feed

7. 1. Uses only small amount of water, which is about
10 % of total quantity used in soil medium.
2. Polyculture: Harvest two products at a time.
3. Purely organic: No insecticides and herbicides
are used here.
4. Can be used in drought prone areas.
5. No soil borne diseases, no weeds.
Why it is better over other system?
4

8. Plants
Fish
Bacteria
Basic biological components
5

9.  Any plant which is commonly grown in
hydroponics will adopt to Aquaponics.
 Leafy vegetables – Lettuce, Amaranthus, Chinese
cabbage, Spinach, Water spinach, Kale etc.
 Others– Tomato, Pepper, Brinjal, Cucumber,
Okra, Zuchini, Broccoli, Garden pea, Swiss chard,
Pak choi, Cauliflower, Taro etc.
Vegetables grown in Aquaponics
6

10. Factors Range
pH 5.5-7.5
Temperature (°C) 16 - 30
Ammonia (mg/l) < 30
Nitrite (mg/l) < 1
Nitrate (mg/l) < 150
Dissolved oxygen (mg/l) > 3
 The addition of calcium hydroxide and potassium hydroxide
can be used to supplement calcium and potassium in
aquaponics with the added benefit of buffering pH.
Somerville et al. (2014)
Water quality requirements for plants
7

11.  Ammonia-Oxidizing Bacteria (AOB): Nitrosomonas
 Nitrite-Oxidizing Bacteria (NOB): Nitrobacter
Bacteria
8

12.  When water temperature drops below 10°C, multiplication
rate of bacteria reduces by 50% or more.
Somerville et al. (2014)
Factors Range
pH 6 - 8.5
Temperature (°C) 14 - 34
Ammonia (mg/l) < 3
Nitrite (mg/l) < 1
Dissolved oxygen (mg/l) 4 - 8
Factors for maintaining a healthy bacterial
colony
9

13. 13
Nile Tilapia Carp
Catfish Rainbow trout
Prawn
Murray cod
Pangasius
Fish species suitable for Aquaponics
10

14. Factors Range
pH 6 - 8.5
Temperature (°C) 22 - 32
Ammonia (mg/l) < 3
Nitrite (mg/l) < 1
Nitrate (mg/l) < 400
Dissolved oxygen (mg/l) 4 - 6
Factors for maintaining fish health
11
Somerville et al. (2014)

15. Factors Range
pH 6 - 7
Temperature (°C) 18 - 30
Ammonia (mg/l) < 1
Nitrite (mg/l) < 1
Nitrate (mg/l) 5 -150
Dissolved oxygen (mg/l) > 5
Ideal parameters for aquaponics as a
compromise between all three organisms
12
Somerville et al. (2014)

16. Fish biomass exceeding the
bio filter carrying capacity
and therefore an accumulation
of toxic ammonia and nitrite
occurs
Fish and bio filter are
correctly sized, but the
system is unbalanced with
too few plants and therefore
too much nitrate
Balancing the Aquaponics system
13

17. Fish and bio filter are
correctly sized, but the
system is unbalanced with
too many plants and
therefore insufficient nitrate
A balanced system where
fish, plants and bacteria are
in dynamic equilibrium
14

18.  The feed rate ratio is a summation of the three most
important variables, which are:
• Amount of fish feed (g/day)
• Plant type (vegetative or fruiting)
• Plant growing space (m2)
 This ratio suggests the amount of daily fish feed per meter
square of growing space.
 It is more useful to balance a system on the amount of feed
entering into the system.
 Recommended daily fish feed rates :
• Leafy green vegetables: 40 - 50 g/m2/day
• Fruiting vegetables: 50 - 80 g/m2/day
Feed rate ratio
15

19. 1. Fish tank/rearing tank: It is made from materials
like Plastic, Fiber glass and Concrete.
2. Air pumps: Inject air into water through air pipes.
3. Filters: Two types of filters. Mechanical filter and
Bio filter.
4. Sump: The sump tank is a water collection tank at
the lowest point in the system.
5. Hydroponic unit: Plants are grown in this unit
with any designs like media bed, NFT or Raft
system.
Structural components
16

20. 17

21. Mechanical filter Bio filter
Filters
18

22. Raft/Deep
Water
Culture
(DWC)
system
Media-
filled bed
system
Nutrient
Film
Technique
(NFT)
Designs of Aquaponics
19

23.  The plants are grown on Styrofoam boards
(rafts) that float on top of water.
 The DWC method involves suspending plants in
polystyrene sheets, with their roots hanging down
into the water.
 This method is the most common for large
commercial aquaponics growing one specific crop
typically lettuce and it is more suitable for
mechanization.
 On a small-scale, this technique is more
complicated than media beds.
1. Raft or Deep water culture system
20

24. 21

25.  Plant bed is filled with gravel, perlite or other
media for growing of plants.
 This bed is periodically flooded with water from
the fish tank and quickly the water drains the bed.
It is usually 20 to 30 min cycle.
 This method uses the fewest components and no
additional filtration, making it simple to operate.
 This system is mostly used for small scale
production.
2. Media-filled bed
22

26. 23

27. Media
Perlite
Pumice
Wood fibre
Gravel
Coir
Rice husk
Vermiculite Rock wool
Expanded Clay aggregate
24

28.  The NFT is a hydroponic method using horizontal
pipes each with a shallow stream of nutrient-rich
aquaponic water flowing through it.
 Plants are placed within holes in the top of the
pipes, and are able to use this thin film of
nutrient-rich water.
 This technique has very low evaporation because
the water is completely shielded from the sun.
 This technique is far more complicated and
expensive than media beds.
3. Nutrient Film Technique (NFT)
25

29. 26

30. 1. Domestic / Small scale
aquaponics unit:
 Aquaponic units with a fish tank
size of about 1000 liters and
growing space of about 3 m2 are
considered small-scale unit.
 Units of this size have been
trialed and tested with great
success in many regions around
the world.
 The main purpose of these units
is food production for domestic
use.
27
Applications of Aquaponics

31. 2. Commercial / Large scale
aquaponics unit:
 Owing to the high initial start-
up cost and limited
comprehensive experience with
this scale, commercial
aquaponics systems are few in
number.
 Most of these units use
monoculture practices, typically
for the production of lettuce.
 Raft or deep water culture
system and NFT are mostly
used for the large scale
production.
28

33. Figure 1: Effects of foliar application of macro and micro-nutrients on the yield
of tomato plants in aquaponic and hydroponic systems.
Rafsanjan, Iran Roosta and Hamidpour (2011)
29
Bars with different letters show significant differences at p ≤ 0.05 (DNMRT)

34. Parameters
Tomato-based
aquaponics
Pak choi-based
aquaponics
Water replenishment (L) 1863.2 569.5
Fish feed consumption (g) 6950.0 6582.4
Fish biomass increase (g) 4345.0 3285.6
Feed conversion ratio (FCR) 1.6 2.0
Plant yield**
Saleable part (g) 13858.2 24897.4
Unsaleable part (g) 21194.4 1429.7
Stastical analysis using Tukey’s comparison test at p < 0.05
Growing bed : 400 liter volume
Table 1: Performance of different aquaponics
Jinan, China Hu et al. (2015)
30

35. Figure 2: Tomato production in ASTAF- PRO system (7 months)
Berlin, Germany Kloas et al. (2015)
31
Growing area : 166.56 m2

36. Parameter Control Gravel Floating NFT
Fish (Murray Cod )
Wet weight (g/rep.) 220.0 ± 16.1 206.7 ± 13.3 266.7 ± 29.6 250.0 ± 25.2
SGR (%/rep./day) 0.90 ± 0.05 0.89 ± 0.06 1.13 ± 0.13 1.09 ± 0.10
FCR 1.01 ± 0.08 1.07 ± 0.07 0.85 ± 0.10 0.90 ± 0.08
Feed fed (g/rep.) 220.0 220.0 220.0 220.0
Lettuce
Biomass gain (g/rep.) 2639.4 ± 28.9 2338.1 ± 14.5 2159.0 ± 9.8
Yield (g/plant) 131.97± 6.46 116.91 ± 3.24 107.95 ± 2.20
Yield (kg/m2) 5.05 ± 0.25 4.47 ± 0.12 4.13 ± 0.08
Stastical analysis using Mann- whitney test at p > 0.05
20 plants per replication
Table 2: A comparison of three different hydroponic sub-
systems (gravel bed, floating and nutrient film
technique) in an Aquaponics test system
Bundoora, Australia Lennard and Leonard (2006)
32

37. Experiment 1 Experiment 2
Lettuce yield
(kg/m2)
Lettuce yield
(kg/m2)
Aquaponics LD
(5 kg/ m3) 2.37
Aquaponics LD
(6 kg/ m3) 5.67
Aquaponics HD
(8 kg/ m3) 2.71
Aquaponics HD
(20 kg/ m3) 5.7
Hydroponics 2.84 Hydroponics 6.02
Significance S Significance NS
LD = Low fish stocking density
HD = High fish stocking density
Table 3 (a): Comparison between aquaponics and
hydroponics lettuce production
Palmerston North, New Zealand Nichols and Savidov (2012)
33

38. Variety Top Weight (g)
Hydroponics
Top Weight
(g)
Aquaponics
Better System Difference
(%)
Gaugin 130.83 168.00 Aquaponics 28
Princess 117.00 246.63 Aquaponics 111
Explore 211.86 293.78 Aquaponics 39
Ashbrook 220.25 266.38 Aquaponics 21
Satre 173.11 223.56 Aquaponics 29
Robinio 177.88 204.43 - -
Obregon 142.50 223.40 Aquaponics 57
Table 3 (b): Comparisons of aquaponic and hydroponic
NFT system in lettuce variety
Palmerston North, New Zealand Nichols and Savidov (2012)
34

39. Figure 3: Mean weight of lettuce during a 90-day culture period in each of the
three tanks (A) in the experimental group 2 and (B) in the experimental
group 3.
Igoumenitsa, Greece Simeonidou et al. (2012)
35
A B
 Initial mean biomass of lettuce (g) in experimental group 1 -
0.22 g and experimental group 2 – 2.47 g
 No. of fish in Tank 1 - 10, Tank 2 – 25 and Tank 3 – 40.
 Stastical analysis using T- test at p = 0.05

40. Experimental group 1 Experimental group 2 Experimental group 3
Tank T1 T2 T3 T1 T2 T3 T1 T2 T3
Number of fish 10 25 40 10 25 40 10 25 40
Initial mean
body Weight (g)
23 23 23 26.8 25.5 26 32.2 30.16 29
Stocking
density
(kg m-3)
1 2.5 4 1.34 3.18 5.2 1.6 3.76 5.8
Final mean
body weight (g)
26.8 25.5 26 32.16 30.1 29 33.9 31.2 32.4
Total initial
biomass (g)
230 575 920 268 637.5 1040 322 754 1160
Total final
biomass (g)
268 637.5 1040 321.6 752.5 1160 339 780 1296
Net biomass (g) 38 62.5 120 53.6 115 120 17.4 27.5 136
FCR 1.36 2.07 1.73 1.13 1.25 1.95 1.53 1.51 1.55
Table 4: Growth performance of fish Nile tilapia in the Aquaponic system
Igoumenitsa, Greece Simeonidou et al. (2012)
36

41. Vegetables With prawn Without prawn
1st crop 2nd crop 1st crop 2nd crop
Total biomass (g)
Lettuce 86.6 84.6 86.2 80.9
Chinese cabbage 179.5 168.5 163.3 165.7
Pak choi 185.2 190.0 172.9 178.3
Average yield (g)
Lettuce 77.5 75.5 78.5 73.1
Chinese cabbage 166.6 154.2 153.5 151.7
Pak choi 167.9 171 155.9 161.2
Nueva Ecija, Philippines
Table 5 : Total biomass (g) and average yield (g) of vegetables in
with and without prawn aquaponics systems
Sace and Fitzsimmons (2013)
37

42. Yield (kg /row)
Rows Aquaponics Control
A 28.169 29.390
B 32.487 23.986
C 32.783 20.864
D 30.052 27.778
E 31.746 21.458
F 33.082 15.367
G 36.362 10.993
Total 177.20 149.84
Area of single row : 2.88 m2
Table 6 (a): Yield of cucumber for Aquaponics and control
treatment
Pabal, Pune Shanbhag (2013)
38

43. Rows Aquaponics Control
No. of
fruits/Row
Average No.
of fruits/Plant
No. of
fruits/Row
No. of
fruits/Plant
A 192 9.1 217 9.4
B 208 9.9 166 7.2
C 239 11.4 176 7.3
D 164 7.8 181 8.2
E 178 7.7 194 8.1
F 211 8.8 115 6.1
G 253 10.5 88 7.3
Average - 9.3 - 7.7
Table 6 (b): Number of fruits of cucumber harvested in
aquaponics and control treatment
Pabal, Pune Shanbhag (2013)
39

44. T1 - Aquaponics system for soilless vegetable culture in gravel bed with fish
tank waste water.
T2 - Hydroponics for soilless vegetable culture in gravel bed with tap water and
T3 - Vegetable culture in soil media with tap water as control.
 Stastical analysis using two sample t- test and treatment means are tested at
1%, 5% and 10% level of significance
Figure 4: The biomass content of Taro plant at final harvest
Mymensingh, Bangladesh Salam et al. (2014)
40

45. T1 T2
Raft aquaponics Rack aquaponics Raft aquaponics
Name of
Crops
Production
(kg/ha)
Name of
Crops
Production
(kg/ha)
Name of
Crops
Production
(kg/ha)
Water
spinach
1025
Water
spinach
2460
Water
spinach
923
Okra 205 Okra 492 Okra 215
Total 2050 Total 4922 Total 1901
Table 7: Vegetable production per hectare in raft and rack
aquaponics systems for three months
Mymensingh, Bangladesh Salam et al. (2013)
41

46. 0
500
1000
1500
2000
2500
T 1 T2 T3
Pungasius Tilapia
Figure 5: Production of Pungasius and Tilapia in all treatments in
raft and rack based system
Mymensingh, Bangladesh Salam et al. (2013)
42

47.  High initial cost
 Chances of system imbalance
 Scientific knowledge about components
 Can’t grow all crops
 Power consuming
Challenges
43

48.  Sustainable and intensive food production
system
 Extremely water efficient
 Completely organic
 Two products from one input
 Environmentally safe
Opportunities
44

49.  From the foregoing discussion, it can be concluded that
aquaponics system was better than hydroponics system
for vegetable production.
 In aquaponics lettuce production was more or equal to
the hydroponics system for vegetable production.
 Pak choi produced maximum yield in with prawn
aquaponics system as compared to lettuce and chinese
cabbage.
 Amongst three aquaponics systems viz. gravel bed,
floating and nutrient film technique, lettuce production
was maximum in gravel bed aquaponics system.
 Pak choi produced more yield than tomato in
aquaponics system.
 ASTAF- PRO system was more suitable for tomato
production than SRAPS system.
Conclusion
45

50. Cont.…
 In aquaponics system tomato yield was increased by
foliar application of macro and micro nutrients and
highest yield was observed with foliar spray of K
application.
 Maximum yield and no. of fruits/plant of cucumber were
obtained with aquaponics system than hydroponics.
 Amongst three system viz. aquaponics, hydroponics and
soil taro gave maximum yield in aquaponics system.
 Water spinach and okra produced highest yield in rack +
raft aquaponics system.
46