Hydroponics Essay, Research Paper
I decided to research Hydroponics, which is the growing of plants without soil in water to which nutrients have been added. Hydroponics has been used for over a century as a research technique, but not until 1929 were experiments conducted solely to determine its feasibility for growing commercial crops. There are now hydroponic home gardens and commercial cropping operations in the United States and many other countries. Under hydroponics, plants can be grown closer together than in the field, thereby increasing yields, and multiple cropping (the growing of several crops in the same tank) can be practiced. In addition to conserving space, hydroponics almost eliminates weed and pest problems. The cost of equipment is high and personnel must be trained.
There are 6 basic types of hydroponic systems: Wick, Water Culture, Ebb and Flow (Flood & Drain), Drip (recovery or non-recovery), N.F.T. (Nutrient Film Technique) and Aeroponic. There are hundreds of variations on these basic types of systems, but all hydroponic methods are a variation (or combination) of these six. Below I will briefly describe them, and how they function.
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 (which is the matter, surrounding the roots) from the reservoir with a wick. This system can use a variety of growing medium. Perlite, Vermiculite, Pro-Mix and Coconut Fiber are the ones that I founds that people recommended on their websites. The only set back that I found with this system is that the plants that are large or use large amounts of water may use up the nutrient solution faster than the wick(s) can supply it, thus not delivering a fully nourished plant.
The second method that I found is the water culture system. It was the simplest of all active hydroponic systems that I found. 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. The one drawback with this system is that very few plants other than lettuce will do well in this type of system. The biggest drawback of this kind of system that I could find is that it doesn’t work well with large or long-term plants.
The third type of system is the Ebb and Flow system, and it 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. The Ebb and Flow is a versatile system that can be used with a variety of growing mediums. The entire grow tray can be filled with gravel or granular Rockwood. Also I found that many people prefer to use individual pots filled with their choice of growing medium. This makes it easier to move plants around or move them in or out of the system. The only real problem that I found with this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), do not hold water very well, there is a vulnerability to power outages as well as pump and timer failures. If this happens the roots can dry out quickly if the watering cycles are interrupted. The only solution that I could find is to use a growing medium that holds more water, this will only give you more time to find and address the problem.
The next type of system is the system that I found the websites, used or recommended the most. It is called the drip system. The drip systems 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.
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. 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 you can fill the reservoir with pH adjusted nutrient solution and then forget it until you need to mix more. A recovery system can have large shifts in the pH and nutrient strength levels that require periodic checking and adjusting.
Another type of hydroponic system is the N.F.T. system. The N.F.T. has a constant flow of nutrient solution, so there is no timer required for the submersible pump. The nutrient solution is pumped into the growing tray (usually a tube) and flows over the roots of the plants, and then drains back into the reservoir. There is usually no growing medium used other than air, this saves the expense of replacing the growing medium after every crop. Under normal circumstances the plant is supported in a small plastic basket with the roots dangling into the nutrient solution. Again a problem I found was that if the power goes out, or the pump fails the roots would dry out very quickly because there is no growing medium.
The last type of hydroponic system is the most high tech and complex system that I found; it is called the aeroponic system. 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 misting is usually done 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.
I could see in the near future that hydroponics might replace conventional methods of farming because it is possible to grow most of the species of plants, even if they are out of season or the climate is not suitable, for that type of plant. Another reason for using hydroponic farming is really not a reason is may come to be the only way to farm because years of crop production an the same land is causing problems, the soil is building up salts from irrigation and fertilization and a great deal of the now highly productive farm land will become unsuitable for crop production in the future.
Some major advantages to hydroponic farming are:
There is a drastic increase of the amount of food per acre (200% to 300 %) with hydroponics over dirt farming.
Hydroponics uses only 10% of the water used by dirt farming.
There is no fertilizer run off when using hydroponics
The produce from hydroponic gardening is usually healthier than that of dirt gardening, because the plant receives a completely balanced nutrient formula including the essential “Micro-nutrients” that are not present is normal “dirt” fertilizers.
Some disadvantages to hydroponic farming are:
The initial cost to get materials and supplies, and the set up
Some can be affected by power outages, all are affected by long term outages
In conclusion, hydroponic farming is a great alternative to conventional soil farming; it produces much richer colors, larger and healthier plants. So if you are serious about planting and maximizing efficiency hydroponic farming may be perfect for you.