1. HYDROPONICS IN HORTICULTURE

2. What is Hydoponics Definition: Hydroponics is the science of growing plants in a medium, other than soil, using mixtures of essential plant nutrient elements, dissolved in water, as ‘’plant food.’’ ‘’Hydroponics ‘’ comes from Latin and means working water.’’ In reality, hydroponics is the growing of plants WITHOUT soil. Today, this technology is widely used to grow lush, healthy indoor plants and premium vegetables, fruits and herbs. Plants are rooted (thus supported) in food-safe floating, rotating trays, and nutrition is provided by water - soluble nutrients.

3. USES AND IMPORTANCE 1. No cultivation : In conventional farming techniques, cultivation, i.e., digging, raking, hoeing, etc, is necessary in order to aerate the soil. 2. Low crop transportation : There is no need to transport crops long distances. This is because lettuce, herbs, other leafy greens, vine, or strawberries can be grown in the same place twelve months per year and supplied over shorter distances to the end –user.

4. Uses and importance contd 3. No weeds or pests : With the use of sterile media for growing, the occurrence of soil-borne weeds is unknown. In addition, the closed system prevents pests and diseases. 4. Uniform quality and flavour : uniform plants of high quality can be expected repeatedly from crop to crop, twelve months of the year.

5. Larger yields : Since there is no competition between individual plants for nutrients, CO 2 and O 2, it is possible to plant significantly closer to each other than in conventional field farming methods. Hydroponics plants reach maturity faster than their conventionally grown counterparts. Little or is no crop loss due to pests and diseases, and environmental damage, as in the case of field-grown crops. With some crops, it is conservatively estimated that under optimum conditions, the hydroponic method will produce in excess of 30 times the yield expected in soil on the same footprint.

6. Extended shelf life : The cultivated vegetables and fruit do not require a washing process before packaging, since there is no soil, pathogens, or herbicide or pesticide residue. In addition, given a longer shelf-life, distribution to remote areas is possible, making new markets available. Environmentally friendly technology Since the technology can be practiced indoors (greenhouse system), it is environmentally friendly by using less water, less land pesticide and herbicide- residue free, pathogen free. It can be operated using alternative energy sources, such as solar, thermal, wind and bio-fuels.

7. Environmentally friendly technology Since the technology can be practiced indoors (greenhouse system), it is environmentally friendly by using less water, less land pesticide and herbicide-residue free, pathogen free. It can be operated using alternative energy sources, such as solar, thermal, wind and bio-fuels.

12. BRIEF HISTORY ON HYDROPONICS BY WILLIAM. F. GERICKE Hydroponic is the growing of plants in water instead of soil. The water must be enriched with nutrients and sometimes oxygenated and also the plant must be placed in some type of inert medium like sand or pelite to anchor the roots. This technique has been there for 70 years and was first introduced by a scientist Jean Boussingault,who grew plants in containers with sand and coal feeding with chemical solution of known make up.

13. Then around 1930’s Prof W. F Gericke saw commercial potential in Boussingault’s techniques‘ and began to use them to grow vegetables, flowers and other types of plants. By then it was referred as nutriculture by William F Gericke who took hydroponics from the lab to the greenhouse Gericke created a sensation by growing tomato vines 8m high in his back yard in mineral nutrient solution rather than soil In the year 1936, Prof Gericke coined the name ‘Hydroponics’ to describe the cultivation of flowering and fruiting plants in solution of water soluble nutrients dissolved in water The term ‘hydroponic’ is derived from two Greek words, Hydro meaning water and Ponos meaning labour (working water)

14. Many civilization have utilized hydroponic growing techniques throughout history e.g. the hanging gardens of Babylon and the floating gardens of the Aztecs of Mexico and those of the Chinese. Since then hydroponically grown vegetables became important to American history e.g. in 1939 the American army and British air force installed hydroponic units in their military bases, and Allied troops ate hydroponically grown vegetables during World War 2.

15. NUTRIENT CONTROL IN HYROPONICS

16. NUTRIENT CONTROL The macro nutrients N,P,K,Ca and Mg are required in plants in large amounts The rest are required in trace amounts B,Zn,Ni,Na,Cu,Mo,Cl,Mn,Fe and chloride Plants have different nutrient requirements between species and growth stages The amount of nutrients in solution can be easily and accurately determined by measuring the electrical conductivity of the solution

17. Nutrient strength is measured with conductivity meters which measure the ability of an aqueous solution to carry an electric current They measure the concentration of solution as the total weight of dissolved salts (1ppM =1mg/litre) A nutrient-rich solution will have a higher conductivity than a less ionic solution As plants grow, their requirements change and so the solution must be changed also to keep the plants growing at their optimum An appropriate refill solution is needed to both replenishes nutrients and water

18. pH control pH affects nutrient availability, The recommended pH for hydroponic cultures is between 5.5-5.8 The addition of acid (phosphoric acid) and alkalis to nutrient solutions is the most common and practical means to adjust pH Vinegar can be used to lower pH levels and also baking soda to raise the level

19. Advantages of Hydroponics 1. Plants can be grown anywhere With hydroponics plants can be grown anywhere where no soil exists and light is available Also in areas where traditional farming is impossible e.g desert regions, mountainous regions

20. 2. Better control over plant growth A hydroponics grower has the freedom to regulate the composition of nutrient solution and the frequency of the feeding of nutrients with ease. The root environment is easily controlled and manipulated for temperature, darkness and nutrient mix. Rather than the use of soil system which is difficult to keep in control due to the complex chemical and biological nature of the soil, nutrients are frequently not available to plants due to poor soil structure or unfavourable soil pH

21. 3. Less work with hydroponics No need for tilling of soil, fumigation, watering, pulling of weeds 4. Water and nutrients are conserved Hydroponics uses less water and nutrients than soil culture because the nutrients can be recycled through the system. This advantage is significant as it can lead to a reduction in the pollution of land and streams with high levels of nutrients In addition, it saves money

22. 5. Pest and disease problems are reduced The chance of soil borne disease is largely reduced as it is a soilless culture system, thus the need to fumigate is much lessened. With soil culture, the animal waste, high residues of pesticides and soil microorganisms applied on to food crops pose a healthy hazard to consumers.

23. 6. Transplanting shock is reduced Seedlings can be easily raised in rockwool (man- made mineral fibre) propagation blocks. These blocks can be then transplanted directly into hydroponic system without a need to prick out the plants as like in soil media Reduced transplanting shock

24. 7. Soil erosion non existence Does not involve the use of heavy machines which compact the soil and results in damage to the soil structure which lead to serious soil erosion problems 8. Increased yield in a short time Plants mature faster e.g tomatoes mature within 4 months from time of seedlings, lettuce take about 8 to 10 weeks. There is no competition by plants for nutrients, so plants can be packed closely together. With some crops such as tomatoes, 3 to 4 times yield increase occurs as compared to soil system

25. Disadvantages of hydroponics 1. Initial cost high Initial cost for construction of the H system is high, so the H farmer may be limited in growing crops that give high returns 2. Uses a lot of electricity/power To keep the oxygen pumps working 3. Plants sensitive to any environment changes If there are deficiencies, the plants will show immediately Also all the plants in the system are sharing the same water and nutrient mix thus if there is a pest or disease infestation occurs it spreads quickly through the entire growing system

26. 4. Associated with water based diseases This results in final loss of the whole system and having to start over 5. Most hydroponic gardens require a growing light This depends on the type of plants, you may need a lamp that stimulates autumn light to force re- growth in plants for example Lettuce and cabbages 6. Sound technological knowhow is required Trained personnel knowledgeable in principles of plant nutrition and operation of commercial hydroponic are necessary to manage H farm, as the failure rates is high in amateur hands

27. Hydroponic systems There are 6 basic types of hydroponic systems; 1.Wick, 2.Water Culture, 3.Ebb and Flow (Flood & Drain), 4.Drip (recovery or non-recovery), 5.N.F.T. (Nutrient Film Technique) and 6.Aeroponic There are hundreds of variations on these basic types of systems, but all hydroponic methods are a variation (or combination) of these six.

28. WICK SYSTEM The Wick system is by far the simplest type of hydroponic system. This is a passive system, which means there are no moving parts. The nutrient solution is drawn into the growing medium from the reservoir with a wick. This system can use a variety of growing medium. Perlite, Vermiculite, Pro-Mix and Coconut Fibre are among the most popular. The biggest draw back of this system is that plants that are large or use large amounts of water may use up the nutrient solution faster than the wick(s) can supply it.

29. The wick system

30. The water culture system The water culture system is the simplest of all active hydroponic systems. The platform that holds the plants is usually made of Styrofoam and floats directly on the nutrient solution. An air pump supplies air to the air stone that bubbles the nutrient solution and supplies oxygen to the roots of the plants. Water culture is the system of choice for growing leaf lettuce, which are fast growing water loving plants, making them an ideal choice for this type of hydroponic system. Very few plants other than lettuce will do well in this type of system. The biggest draw back of this kind of system is that it doesn't work well with large plants or with long-term plants.

31. The water culture system

33. EBB & FLOW - (FLOOD AND DRAIN) The Ebb and Flow system works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer. When the timer turns the pump on nutrient solution is pumped into the grow tray. When the timer shuts the pump off the nutrient solution flows back into the reservoir. The Timer is set to come on several times a day, depending on the size and type of plants, temperature and humidity and the type of growing medium used.

34. The Ebb & Flow is a versatile system that can be used with a variety of growing mediums. The entire grow tray can be filled with Grow Rocks, gravel or granular Rockwool. Many people like to use individual pots filled with growing medium, this makes it easier to move plants around or even move them in or out of the system. The main disadvantage of this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), there is a vulnerability to power outages as well as pump and timer failures. The roots can dry out quickly when the watering cycles are interrupted. This problem can be relieved somewhat by using growing media that retains more water (Rockwool, Vermiculite, coconut fibre

35. EBB & FLOW - (FLOOD AND DRAIN)

37. DRIP SYSTEMS: RECOVERY / NON-RECOVERY Drip systems are probably the most widely used type of hydroponic system in the world. Operation is simple, a timer controls a submersed pump. The timer turns the pump on and nutrient solution is dripped onto the base of each plant by a small drip line. In a Recovery Drip System the excess nutrient solution that runs off is collected back in the reservoir for re-use. The Non-Recovery System does not collect the run off.

38. A recovery system A recovery system uses nutrient solution a bit more efficiently, as excess solution is reused. This also allows for the use of a more inexpensive timer because a recovery system doesn't require precise control of the watering cycles. A recovery system can have large shifts in the pH and nutrient strength levels that require periodic checking and adjusting

39. The non-recovery system The non-recovery system needs to have a more precise timer so that watering cycles can be adjusted to insure that the plants get enough nutrient solution and the runoff is kept to a minimum. The non-recovery system requires less maintenance due to the fact that the excess nutrient solution isn't recycled back into the reservoir, so the nutrient strength and pH of the reservoir will not vary. This means that one can fill the reservoir with pH adjusted nutrient solution and then forget it until one needs to mix more

40. Nutrient Film Technique NFT is a hydroponic technique whereby a very shallow stream of water containing all the dissolved nutrients required for plant growth is recirculated past the bare roots of plants in watertight gully also known as channels. NFT provides no medium support for roots. Typically roots sit in a long sloping irrigation channel.

41. Basic design requirements for NFT Channels need suitable slope for drainage Channels must be wide and deep enough to comfortably accommodate the plant’s mature root system. Undersized channels can become choked with roots which can lead to damming, overflowing or create stagnant areas that fail to drain fully. Last plant should be positioned well upstream of the drain’s outlet so that roots don’t block the drain.

42. How does it work Nutrient is introduced at the high end of the channel & allowed to flow over the roots after which it drains into a nutrient reservoir. It is then re-pumped back into the channel to repeat the watering process. NFT can be intermittent feed cycle or a continuous feed cycle. An intermittent feed cycle is regulated by a timer & repeated many times/hr.

43. Nutrient Film Technique (N.F.T)

44. N.F.T Technique

45. Usually achieves better aeration of roots because roots are exposed to air between each feed. In a continuous flow solution culture, the nutrient solution constantly flows past the roots. Ideally, the depth of the recirculating stream should be very shallow, little or more than a film of water, hence the name nutrient film. This ensures that there is abundant supply of oxygen to the roots of plants.

46. Advantages of NFT Plant roots are exposed to adequate supplies of water, oxygen & nutrients. Absence of medium makes it easy to inspect roots for disease signs and symptoms. Lower water & nutrient consumption. Environmental friendly-minimal potential for localized groundwater contamination. Higher yields of high quality produce are obtained over an extended period of time!!

47. Disadvantages of NFT Plant roots can easily clog the trough & impede the flow of nutrients so there would be need for periodic trimming. Power outages and pump failure can result in plant death within a few hrs, especially in hot weather. Not suitable for plants with large tap root system e.g carrots.

48. AEROPONIC SYSTEM The aeroponic system is probably the most high-tech type of hydroponic gardening. Like the N.F.T. system above the growing medium is primarily air. The roots hang in the air and are misted with nutrient solution. The mistings are usually every few minutes. Because the roots are exposed to the air like the N.F.T. system, the roots will dry out rapidly if the misting cycles are interrupted. A timer controls the nutrient pump much like other types of hydroponic systems, except the aeroponic system needs a short cycle timer that runs the pump for a few seconds every couple of minutes

49. AEROPONIC SYSTEM