Soil-less cultivation is a new advanced method for improving cultivation of different vegetable crops. It is a method of growing vegetables without the using soil as a rooting medium, in which the inorganic nutrients absorbed by the roots are supplied through irrigation water. It includes hydroponics, aeroponics and aquaponics. Hydroponics is the growing of vegetables in a fed with a solution containing a mixture of macro and micro-nutrients. Aquaponics is the technique in which, aquatic animals such as snails, fish, crayfish, prawns, etc., are grown in tanks with combination of hydroponics with vegetables are grown in water in a symbiotic environment. In aeroponics system, sealed root chamber is used as reservoir for nutrient solution where the plants above the reservoir cover with polystyrene/other material. It must be supported or hanged through holes in the expanded cover and are misted with nutrient solution to keep it always moist. Soil- less cultivation has been followed in number of vegetables such as, tomato, chilli, brinjal, green bean, bell pepper, cauliflower, cucumber, melons, radish, onion, lettuce, beet, winged beans, water spinach, spinach, coriander, and so on. Soil-less cultivation helps in early nursery raising and easy management, production of healthy vegetable seedlings free from disease, insects and pest. It has various benefits like; year-round production and off season, higher productivity and uniform quality, management of insect-pests, diseases and weeds is easier which helps in more efficient and less use of resources. Soilless culture is rapidly gaining its popularity and get accepted in many countries, especially in commercial vegetable production. Soilless culture could well dominate food production in the future As population increases and cultivable land declines due to poor land management, so people turn towards new technologies like soilless culture. In order to popularize soilless culture, it is very important to provide scientifically proven results for awareness and massive production of vegetable through soilless farming system and with this advanced technologies and techniques involved in soilless vegetable cultivation can be said as next-generation crop science hence, it can open a doorway to establish a new civilization in outer space.

1. Soil-less Farming in Vegetable Crops
Tamil Nadu Agricultural University
Horticultural College and Research Institute
G. Sandeep
PhD (Horticulture) Vegetable Science

2. Contents
• Introduction
• Reasons to follow Soilless farming
• History Of Soilless Farming
• Soilless Culture - Types of soilless
cultures
• Closed Soilless Culture
• Open Soilless Culture
• Types of “Ponics” systems
• Hydroponics
• Aeroponics
• Aquaponics
• Advantages of aeroponics over
hydroponics
• Types of fishes widely used in aquaponics
• Nutrient Solution
• Factors affecting nutrient solution
• pH
• EC
• Temperature
• Light
• Oxygenation
• Water quality
• Water disinfection
• Growth media
• Properties of good growth media

3. Introduction
• Soil is usually the most available
growing medium for all kinds of
plants
• Almost all crops are produced
either directly or indirectly in open
field soil
• Existing level of biotic and
abiotic stress in soil severely
affect agriculture and horticulture
crops
• On the other side, shrinking of
agricultural land, due to
urbanization and industrialization

4. India’s Shrinking Farms
Average farm size (In Hectares)
2.00 ha 1.08 ha
1.41 ha
1976-77 2015-16
1995-96
Source : Agricultural Census, Census of India (2015-16)

5. Reasons to follow Soil-less farming
• To overcome abiotic stress conditions such as
 Salinity
 Drought
 Rocky and sandy soil
 Insufficient nutrient availability
• To overcome biotic stress conditions such as
 Pest
 Diseases
• Shrinkage of farming lands
 Industrialization
 Urbanization

6. History of Soilless Farming

7. Soil-Less Culture
Hydroponics
Wick System
Nutrient Film
Technique (NFT)
Deep Water Culture
(DWC)
Drip hydroponics
system
Ebb and Flow (Flood
and Drain) system
Aeroponics Aquaponics
Closed Loop System Open Loop System

8. Shrestha and Dunn, 2013
Pros Cons
 Affordable
 Low maintenance
 No nutrient pump
 Limited Oxygen & Slower growth rate
 No nutrient recirculation
 Prone to algae growth
 Cheapest - active systems
 Simple set up
 No nutrient pump
 Reliable
 Risk of root rot
 Slow growth rate
 Frequent refill
 Affordable
 Low maintenance
 Excess nutrient solution recirculates
 Prone to algae growth
 Technical malfunctions
 Sufficient oxygen flow
 Excess nutrient solution recirculates
 Prone to clogging
 Malfunctions
 Excess nutrient solution recirculates
 Space efficient
 Prone to clogging
 Malfunctions
 Crop loss
 Maximum nutrient absorption  Prone clogging
 High tech
 Time intensive

9. Hydroponics
• Hydro or Water – Greek word ; Ponos – Working
• Hydroponics is an artificial means of providing plants
with support and a reservoir for nutrients and water
• Its was first named by “W.F. Gericke” in 1930’s
• Plants - grown in inert medium - Rocks, coir fibre etc. -
Mixture of primary, secondary and micronutrients
• Plants like vegetables, fruits, herbs and flowers can be
grown in hydroponics.
Kalaivanan & Selvakumar, 2016

10. • Plants grown in Hydroponics had consistently
• Superior quality
• High yield
• Rapid harvest
• High nutrient content

11. Commercially cultivated crops in hydroponics
System
Sharma et al., 2018
• Sharma et al., 2018 reported that Quality of produce, taste and nutritive value of end products is
generally higher than the natural soil based cultivation.
• Various experimental findings are carried out in leafy greens (lettuce, spinach, parsley, celery etc.)

12. Vegetable production under soil-less culture in India
VEGETABLES PRODUCTION (g/m2/day)
Carrot 56.5
Cucumber 226
Garlic 57
Potato 56.5
Green Bean 113
Lettuce 226
Salad greens 226
Tomato 113
(Singh & Singh, 2012)

13. Aim
• To compare the performance of wick irrigation with nutrient film technique (NFT)
hydroponic system for greenhouse lettuce production
Materials and Methods
• Location : School of Agricultural Engineering (FEAGRI), University of Campinas (Brazil)
• Plant : Lettuce – Vanda
• Wick System with Coconut Coir
• Wick System with Pine Bark
• NFT
CASE STUDY 1 – 2016 - Brazil

14. Conclusion
• The wick irrigation system with self-compensating troughs, irrespective of substrate, showed
higher lettuce yield than the NFT system
• Wick irrigation systems resulted in lettuce plants with Limited manpower and electrical power.

15. Aeroponics

16. • Belongs to closed soilless culture
• Most high-tech type of hydroponics
system
• Roots are made to hang from the
supporting platforms
• Pump – pressurized – mist of
nutrient solution
• Roots – dry rapidly – short misting
cycles are maintained with short
timer cycles
Imran ali et al., 2018

17. • Misting of nutrient solution is achieved by various types of nozzles
Ultrasonic atomization fogger
• Imran et al 2018, stated that system uses
constant pressure – 60 – 90 Psi
• Functioning of entire system is
computerized and managed precisely by
various “Sensors”
High-pressure atomization nozzle Pressurized Airless nozzle

18. Advantages of aeroponics over hydroponics
Parameters Aeroponics Hydroponics
Roots Suspended in air Immersed in nutrient rich
medium
Solution Sprayed as fine mist Dissolved in the medium
Crop Yield Better quality with more food due to
aeration (Oygenated)
Harvest poor – due to less
aeration
Exposure to Co2 Greater Lesser
Spread of Diseases Reduced Possible
Water Requirement Less More (Twice of aeroponics)

19. • Aim
• To compare growth response of lettuce in aeroponics, hydroponics and
substrate culture
• To study the root characteristic in 3 different culture
CASE STUDY 2 – 2018 - Texas

20. Materials & Methods
• Aeroponics system – A frame with multiple Styrofoam
• AutoJet® spray system was installed and monitored automatically
• Hydroponics - NFT system – PVC trough with 1% slope
• Substrate Culture – 50% Peat + 50% Perlite – 1.2 L/Day (nutrient
solution)
• Plant : Lettuce – Nenglv Naiyou and Dasusheng
• Until two true leaf stage – watered with 50% Hoagland’s nutrient
solution
• Then with full strength Hoagland’s nutrient solution
• Plant parameters – Plant growth, biomass, Shoot: Root ratio is
estimated

21. Conclusion
• Aeroponics remarkably improved root growth
• Greater root growth did not lead to greater shoot growth
compared with hydroponics, due to the limited availability of
nutrients and water
• For crops like lettuce for plants parts above ground are produced
via “Hydroponics”

22. Aquaponics

23. Aquaponics = Aquaculture + Hydroponics
• Aquaponics – aquatic animals like Fish, snails, prawns
are grown in tanks with combination of hydroponics
• Its is symbiotic environment (Plants and fish)
• In aquaculture – fish excretion is toxic due to high level
of ammonia
• In aquaponics – water from aquaculture – passed –
hydroponics system – broken by “NITRIFYING
BACTERIA” in growing media and nitrates are utilized
by plant growth
• Biofilters are used to maintain the culture of nitrifying
bacteria – Nitrosomonas sp. & Nitrobacter sp.
Andreas & Ranka 2017

25. Aquaculture can be combined with three
systems of hydroponics
• Deep Water System (DWC)
• Nutrient Film Technique System
(NFT)
• Flood and Drain System
• Aquaculture + DWC is most widely used
Aquaponics system
Abigail Cohen 2018

26. Types of fishes widely used in aquaponics
Air-breathing fishes
Anabas
Pangasius
Gourami
Water breathing fishes
Tilapia
Red-bellied Natter
Rohu
Mrigal
Catla
Ornamental Fish

27. Aim
To evaluate effluent of Bio-floc Technology (Tilapia culture) on
aquaponics production of lettuce
CASE STUDY 3 – 2017 - Brazil

28. • Material & Methods
• Lettuce – 3 varieties - Red lettuce, Butter lettuce & Crispy lettuce
• Clear-Water Recirculation system is maintained as control
• A total of 6 treatments replicated thrice for 21 days
• BFT- RED
• CW- RED
• BFT- BUTTER
• CW- BUTTER
• BFT- CRISPY
• CW-CRISPY
• Fish : Tilapia (Oreochromis niloticus) in 500 L BFT culture tank

29. • Fish Performance in
aquaponic system
• In both systems BFT &
CW survival rate of
Tilapia fish is 95%
• But growth is higher in
BFT
• Growth is higher is due
to presence of abundant
“PLANKTONIC
ORGANISM”

30. Conclusion
• BFT effluent from tilapia culture -
alternative for aquaponics
production, enhancing plant
yield.
• Among lettuce varieties, butter
lettuce showed the best growth
results.
Table 2 :Productive performance of lettuce varieties in aquaponics system, influenced by wastewater bioflocs (BFT) and clear water (CW) during the experimental period

31. NUTRIENT SOLUTION

32. Nutrient solution for hydroponics system
• Nutrient solution for hydroponic systems - aqueous solution
containing mainly inorganics ions from soluble salts of essential
elements for higher plants
• Currently 17 elements are considered essential for most plants,
- C, H , O, N, P, K, Ca, Mg, S, Fe, Cu, Zn, Mn, Mo, B, Cl and Ni
• Carbon and oxygen is absorbed from atmosphere
• pH and EC of the nutrient solution decides the growth of the
plants
Steiner,
1968

33. • Success of soilless
farming - balanced
nutrient solution
• Dilution of these nutrients
are based on the pH
• Optimum pH is 5.2 - 6.5
• Lack of nutrients in
nutrient solution is
checked every 2 weeks
• Nutrients designed for
hydroponics should be
used
Eg: UREA (Not preferred) –
NITRATE FORM are used

34. Sources of nutrient elements
• The best time to monitor the nutrient solution is between 6.00 and 8.00 am –
water requirement will vary everyday
• Solution should be applied to roots without wetting leaves - it causes damage
• About 20 – 50% solution should be drained off - avoid – accumulation of toxic
ions Sardare et al, 2013

35. Commonly used nutrients solution in hydroponics
Cooper, 1988; Steiner, 1984; Windsor & Schwarz, 1990

36. Factors affecting nutrient solution
pH
• The pH is a parameter that
measures the acidity or alkalinity of
a solution.
• This value indicates the relationship
between the concentration of free
ions H+ and OH- present in a
solution
• Optimum range of pH is about 5.2 –
6.5
Steiner,

37. EC
• The total ionic concentration - nutrient solution - determines the
growth, development and production of plants
• The total amount of ions of dissolved salts in the nutrient
solution exerts a force called osmotic pressure
Jensen, 1980; & Tanji,
1990

38. • Nutrient Solution Management
• In the nutrient solution parameters such as temperature, pH,
electrical conductivity, oxygen content should be controlled
properly
• pH regulation - During Nutrient uptake – Balance of anions
over cations – plant excretes OH- or HCO3-– Physiological
alkalinity
• Chemical adjustment is widely used - addition of acids –
Nitric acid, sulphuric acid or phosphoric acid
• EC Management - absorption of water & nutrients from
nutrient solution cause imbalances in EC.
• It can be managed by continuous monitoring and recycling
of water.
(Urrestarazu, 2004)

39. Temperature of Nutrient Solution
• Role in nutrient absorption and healthy root system
• Optimum nutrient solution temperature - 20-22ºC
• If it exceeds 23-23.5ºC - plant roots will die
• It can be managed by temperature control systems - Thermostats
Oxygenation of nutrient solution
• Consumption of O2 increases when the temperature of nutrient solution increases
• Below 3 or 4 mg L-1 of dissolved oxygen – inhibits plant growth
• Oxygen can be controlled by “Oxy-fertigation”
• Commercially – Potassium Peroxide is used 1g/Lit as oxygen generator in vegetable
hydroponic system.
Libia & Fernando , 2012

40. • Aim
• To enhance the iodine content in sweet basil & Lettuce through
hydroponics system
• To find out the best hydroponic system (Floating & Aeroponics System)
CASE STUDY 4 – 2021 - Italy

41. • Materials & Materials
• Basil (Ocimum basilicum L.) var. Tigullio
• Lettuce (Lactuca sativa var. crispa L.) var. Salad Bowl
• Seeds – Sown – Plug tray with Rockwool and Vermiculite
• Transplanted in Floating and Aeroponics after 20 days
• pH – 5.6 & EC – 2.32 dSm-1
• In both systems, nutrient solution is continuously aerated with oxygen
• Iodine Concentration Maintained is 0.07 μM & 10 μM
• Iodine supplement Used “Potassium Iodide”

42. Basil
(Table 1)
Lettuce
(Table 2)

43. Conclusion
• Nutrient solution with 10 μM is effective in
biofortification of both basil and lettuce leaves
• Plant growth and leaf quality are not affected by
higher iodine concentration
• Basil – 6 grams (40 – 94% RDI)
• Lettuce – 26 grams (27% - 62% RDI)
• Both hydroponics system were effective among
these 2 systems – Aeroponics are effective due
to aeration (O2)
23.58
6.8
Leaf iodine content in basil (A) and lettuce (B)

44. Aim
• To study the characteristic response of Amaranthus paniculatus to heavy metal
exposure (Nickel) represents for phytoremediation
• To study the plant growth under heavy metal concentrated hydroponic environment
Materials & Methods
• Plant : Amaranthus paniculatus
• 1/6th strength of Hoagland’ solution – Till germination
• After 3 weeks – Plants transferred to Nickel Concentrated nutrient solution –
• Treatments: 0 (control), 25, 50, 100 and 150 μM (Nickel Nitrate Hexahydrate)
CASE STUDY 5 – 2013 - Italy

45. • Decrease in plant organ dry mass with the
enhancement of nickel (Ni) concentration
in the solution
• Suggesting a good metal tolerance at 25
μM Ni and a marked sensitivity at 150 μM
Ni
• Ni Accumulation – Root > Stem > Leaves
• Plants exposed to 25 μM Ni succeeded in
removing almost 60 % of the initial Ni
content of the solution showing no stress
symptoms
Ni uptake Ratio
Plant Ni content

46. •If nutrient concentration - too
high - the conductivity controller
could turn on the fresh water
pump to dilute the nutrients
•If Nutrient concentration - too
low - the conductivity controller
could turn on the nutrient
pumps.
•pH became too high, the pH
controller could open the solenoid
valve, allowing carbon dioxide to
flow into the water reservoir
•Carbon dioxide reacts with water
to form carbonic acid, which
lowers the pH of the solution.
High nutrient concentration > high conductivity reading > add fresh water
Low nutrient concentration > low conductivity reading > add nutrients
Overly alkaline solution > high pH reading > add carbon dioxide
Sensor – Switch (Potentiometer) – Solenoid valve - Pumps

47. Automated Hydroponic sensor system – NIDO Pro®
Water Balancing
 pH
 EC
 Water temperature
Climate Control
 Temperature
 Humidity
 Vapour Pressure Deficit
Source : NIDO Pro®

48. Source : NIDO Pro®

49. Light requirement in hydroponics
• Minimum of 8 – 10 hours of light/ day is
required
• Sunlight is ideal for the hydroponic plants
• If its not available – Energy saving LED
lamps are required
• Seedling and Vegetative stage - More
blue spectrum with pinch of red spectrum
• Flowering stage – More Red spectrum
with pinch of Blue spectrum
Nemali & van Iersel, 2004

50. 380 nm – 390 nm
Ultraviolet
Guide plant flowering, Sterilization & Inhibit Leggy
400 nm – 410 nm
Blue Violet
Promotes pigmentation, prevent harmful insects
440 nm – 470 nm
Blue
Promote vegetative Growth
510 nm – 535 nm
Green
Almost plants don’t absorb green colour – Less required
Enhance the taste & increase nutritional content
600 nm – 610 nm
Orange
Improve the quality of root and leaves
640 nm – 670 nm
Red
Speeds up seed germination & Great photosynthetic effect
730 nm – 840 nm
Deep Red
Promote plant growth, flowering – Increases YIELD
585 nm – 595 nm
Yellow
280 nm
Ultraviolet
Reduces rate of photosynthesis
V
I
S
I
B
L
E
L
I
G
H
T
U
V
Leyla Bayat, 2018
IR

51. Water Quality
• Water quality is maintained as it has been taken from various sources
Lake
Rainwater
Rivers
Underground Reservoir
Treated water
• It should be free of pathogens
• Water quality decreases in the closed system – continuous recirculation of water
Tognoni et al. (1998)

52. Water disinfection
• Major disadvantages - closed systems - rapid dispersal of soil-borne pathogens by the
recirculating nutrient solution. To eliminate these pathogens - disinfection methods are
followed
• Ozone treatment
• UV disinfection
• Heat treatment (95ºC for 30 seconds)
• Slow sand filtration
• Electrolysed water (Anodic Oxidation – AO)
• Hydrogen peroxide ( cheapest disinfection method – 400ppm)
• Membrane filtration (RO)
• Chlorination (Calcium Hypochlorite)
Zhang and Tu, 2000

53. Growth Media

54. • Growth substrates are the substitute for soil
• This provides
• Water
• Nutrients
• Oxygen
• Physically support the plant
• Soil-less cultivation allows absence of soil-borne pathogens; safe
alternative to soil disinfection
• Nutrients and water are applied more evenly to the plants
• No risk of accumulation of phytochemical residues
• Various growth substrates are available, they are classified as
El-Kazzaz et al., 2017

55. SUBSTRATE
ORGANIC
PEAT
Coconut Fibre
INORGANIC
Sand
Pumice
Vermiculite
Perlite
Expanded Clay
Stone wool
SYNTHETIC
Polystyrene
Polyurethane
foam
Patil et al., 2020

56. Properties of good growth media
• Inert – Non-reactive with nutrients
• Aeration and drainage
• Can be mined or produced by the industry
• Low cost
• Cation exchange capacity - More
• Easy to use and Environmental friendly
• Free from grit, heavy metals and radioactive pollutants and Cleanliness
• Has constant quality
• Having a lifespan for at least three years
• Recyclable
• Neutral pH
• Easily sterilized

57. Aim
• To find Alternative and potential growth substrate for hydroponics system
• To compare efficiency with other known growth substrate
Material & Methods
• Substrate – Perlite (PL), Rice Husk Biochar (RB) (500ºC) and PL+RB (1:1)
• Plants – Cabbage, Dill, Mallow, Lettuce and Tatsoi ; Hydroponic System – NFT
CASE STUDY 6 – 2017 - Korea

58. • PL and RB surface studied – SEM
• Shoot length and fresh/dry masses of grown
plants under RB substrate - decreased by
49% compared to PL substrate
• PL + RB substrate - approx. 2-fold
increases in shoot length, number of leaves,
and fresh/dry masses of leafy vegetable
plants compared with those grown in PL
substrate

59. Conclusion
• RB decreased algal growth – thus ensure the safety of vegetables for human
consumption
• PL + RB - effective technology for the better management of unwanted algal
growth in nutrient solutions and high production of leafy vegetables
• PL + RB substrate can be recommended as promising hydroponics substrate
PL RB
Beneficial microorganism

60. Pest and Disease Management

61. Plants grown in soilless culture may be attacked by the some pests and diseases as cultivated traditionally in
soil.
Pest
• Pest can be effectively controlled in greenhouse condition with regular observation
• Biopesticides are used – NSKE, Custard Apple Seed Extract, etc.
• Diseases
• It is essential to maintain sterile root zone in hydroponics system
• Its is difficult to minimize the pest pathogens in root zone (Raviv et al., 1998)
• Diseases - soil borne – in hydroponics due to changed microclimate airborne diseases will be spread
(Gohler and molitor 2002)
• Common diseases in hydroponics – Wilt - Fusarium wilt & Verticillium wilt
• Pythium sp. & Phytophthora sp. (Savvas 2002)
Mamta et al ., 2013

62. Management
• No effective fungicides – safe – in hydroponic system
• Only Metalaxyl (systemic), effective – Phythium sp.
• Heat treatment of nutrient solution - found effective in hydroponics and aeroponics – Tomato and ginger
respectively (Koohakan et al., 2008)
• UV treatment of nutrient solution (Zhang, W., and J. C. Tu 2000) – Against Phythium sp In tomato
• Diseases - Destroys main roots - Found
abundance – cucumber and lettuce
(Schnitzler 2003)
• Biggest problems are caused from “
Phytopathogenic fungi” – produces
zoospores
Singh et al., 2012

63. Objective
• To control the development of diseases caused by
pathogenic microorganisms - Pythium spp & Fusarium
oxysporum
Materials and Methods
• Filtering Unit : GI pipe (150 cm in length and 220 cm in
inner diameter) filled with pozzolana particles as the
filtering medium
• Tomato Plants - 3 varieties - 3-year survey were Allura
for the first year, Camaro for the second year and
Lemance for the last year
• Closed Loop system with circulating nutrient solution
Pythium sp.
Fusarium oxysporum
CASE STUDY 7 – 2006 - France

64. Conclusion
• It is found that this biofilter (pozzolana)
removed more fungi than bacteria under
tomato production conditions.
• Pythium spp., >99% were eliminated over the
3-year survey.
• But, against Fusarium oxysporum, efficacy fell
within 92.7 and 99.3%
• Necrotic symptoms were only observed in
September, i.e. at the end of the cultural
season
• Filtration proved to be a helpful technique
CFU – Colony Forming Unit
Fig5: Assessment over three years of Pythium spp. root
colonization

65. Advantages & Disadvantages of soilless culture
ADVANTAGES
• Production augmentation
• Water control
• Monitor of plant nutrition
• Purge practices
• Monitor root surroundings
• Crop diversity
• Agriculture of land inappropriate
• Alleviation of labour requirements:
DISADVANTAGES
• High capital investment
• The shortage of technicians and skilled labor
• The risk of Pathological Injuries

66. Future thrust
• High Population – Surging Land – In Tokyo - Rice production
hydroponics – 4 harvest cycles instead of 1 harvest - annually
• Dry & Arid Regions – Efficient usage of water
• Visible light spectrum - more fresh leaves - Year round
production
• Lunar - Martian Greenhouses – Earth mimic Greenhouse - NASA
• Studies on plant behaviour in space - Research
• Effective usage of abandoned constructed and Unused
structures
• “Oraganitech” - Hydroponics in large shipping containers
• “Growing underground” – London bomb shelter (WW II)