The study of crop nutrition began thousands of years ago. Ancient history tells us that various experiments were undertaken by Theophrastus (372-287 B.C.), while several, extant botanical writings of Dioscorides date from the first century AD.[1]
The earliest published work on growing terrestrial plants without soil was the 1627 book, Sylva Sylvarum by Sir Francis Bacon, printed a year after his death. Water culture became a popular research technique after that. In 1699, John Woodward published his water culture experiments with spearmint. He found that plants in less pure water sources grew better than plants in distilled water. By 1842 a list of nine elements believed to be essential to plant growth had been made out, and the discoveries of the German botanists, Julius von Sachs and Wilhelm Knop, in the years 1859-65, resulted in a development of the technique of soilless cultivation.[1] Growth of terrestrial plants without soil in mineral nutrient solutions was called solution culture. It quickly became a standard research and teaching technique and is still widely used today. Solution culture is now considered a type of hydroponics where there is no inert medium.
In 1929, Professor William Frederick Gericks of the University of California at Berkeley began publicly promoting that solution culture be used for agricultural crop production.[2] He first termed it aquaculture but later found that aquaculture was already applied to culture of aquatic organisms. Gericke created a sensation by growing tomato vines twenty-five feet high in his back yard in mineral nutrient solutions rather than soil.[3] By analogy with the ancient Greek term for agriculture, geoponics, the science of cultivating the earth, Gericke introduced the term hydroponics in 1937 (although he asserts that the term was suggested by Dr. W. A. Setchell, of the University of California) for the culture of plants in water (from the Greek hydros, "water", and ponos, "labor").[1]
Reports of Gericke's work and his claims that hydroponics would revolutionize plant agriculture prompted a huge number of requests for further information. Gericke refused to reveal his secrets claiming he had done the work at home on his own time. This refusal eventually resulted in his leaving the University of California. In 1940, he wrote the book, Complete Guide to Soilless Gardening.
Two other plant nutritionists at the University of California were asked to research Gericke's claims. Dennis R. Hoagland and Daniel I. Arnon wrote a classic 1938 agricultural bulletin, The Water Culture Method for Growing Plants Without Soil,[4] debunking the exaggerated claims made about hydroponics. Hoagland and Arnon found that hydroponic crop yields were no better than crop yields with good quality soils. Crop yields were ultimately limited by factors other than mineral nutrients, especially light. This research, however, overlooked the fact that hydroponics has other advantages including the fact that the roots of the plant have constant access to oxygen and that the plants have access to as much or as little water as they need. This is important as one of the most common errors when growing is over- and under- watering; and hydroponics prevents this from occurring as large amounts of water can be made available to the plant and any water not used, drained away, recirculated, or actively aerated, eliminating anoxic conditions which drown root systems in soil. In soil, a grower needs to be very experienced to know exactly how much water to feed the plant. Too much and the plant will not be able to access oxygen; too little and the plant will lose the ability to transport nutrients, which are typically moved into the roots while in solution.
These two researchers developed several formulas for mineral nutrient solutions, known as Hoagland solutions. Modified Hoagland solutions are still used today.
One of the early successes of hydroponics occurred on Wake Island, a rocky atoll in the Pacific Ocean used as a refueling stop for Pan American Airlines. Hydroponics was used there in the 1930s to grow vegetables for the passengers. Hydroponics was a necessity on Wake Island because there was no soil, and it was prohibitively expensive to airlift in fresh vegetables.
In the 1960s, Allen Cooper of England developed the Nutrient film technique. The Land Pavilion at Walt Disney World's EPCOT Center opened in 1982 and prominently features a variety of hydroponic techniques. In recent decades, NASA has done extensive hydroponic research for their Controlled Ecological Life Support System or CELSS. Hydroponics intended to take place on Mars are using LED lighting to grow in different color spectrum with much less heat.
In 1978, hydroponics pioneer Dr. Howard Resh published the first edition of his book "Hydroponics Food Production." This book (now updated) spurred what has become known as the 3-part base nutrients formula that is still a major component of today's hydroponics gardening. Resh later went on to publish other books, and is currently in charge of a highly advanced hydroponics research and production facility in the Caribbean.
Sunday 27 December 2009
Tuesday 22 December 2009
Basic Hydroponic Systems and How They Work
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. Scroll down this page (or click on the system names) to see drawings and a description of each type of hydroponic system.
1. 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. Free plans for a simple wick system are available (click here for plans).
This system can use a variety of growing medium. Perlite, Vermiculite, Pro-Mix and Coconut Fiber 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.
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.
This type of hydroponic system is great for the classroom and is popular with teachers. A very inexpensive system can be made out of an old aquarium or other water tight container. We have free plans and instructions for a simply water culture system (click here for free plans).
The biggest draw back of this kind of system is that it doesn't work well with large plants or with long-term plants.
3. 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.
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 fiber or a good soiless mix like Pro-mix or Faffard's).
4. 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.
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.
5. N.F.T.(Nutrient Film Technique)
This is the kind of hydroponic system most people think of when they think about hydroponics. N.F.T. systems have a constant flow of nutrient solution so 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, which saves the expense of replacing the growing medium after every crop. Normally the plant is supported in a small plastic basket with the roots dangling into the nutrient solution.
N.F.T. systems are very susceptible to power outages and pump failures. The roots dry out very rapidly when the flow of nutrient solution is interrupted.
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 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.
reference by http://www.simplyhydro.com/system.htm
Monday 14 December 2009
The Basic Concepts Hydroponic Systems
There's much to learn young hydroponics Padawan about the boat you just jumped in and it's best if we start at the base of it all. If you're ever planning on getting home hydroponic systems to grow your plants in, you will want to take heed of these concepts that I'm about to detail in the following article.
The Basic Concepts Hydroponic Systems
- Instead of soil, we will be using water and a nutrient solution to grow the plant in
- A hydroponic system needs to find a balance between feeding and drowning plants
- A hydroponic system generally refers to every aspect involved in plant growth, ranging from the container to the growth media or the lighting system. In other contexts, a home hydroponic system can refer strictly to the method you're using to grow the plants with: ebb and flow, water culture, NFT, aeroponics and so forth.
The Basic Concepts Behind Nutrition in Home Hydroponic Systems
- Your plants need several nutrients, which are divided into two groups, primary and secondary. The primary group contains three elements, Nitrogen, Phosphorus and Potassium, whereas the secondary group contains over 20 elements, the most important being Calcium, Iron, Magnesium, Manganese, Zinc and Sodium.
- Too much of the same nutrient can develop a toxicity in your home hydroponic system's solution.
- Too little of the same nutrient can develop a deficiency in your home hydroponic system's.
- Some nutrients lock each other out, so by developing a toxicity in one nutrient, you automatically cause a deficiency in another. This is often problematic in finding the cause of a deficiency (i.e. You get a lot of Magnesium in your nutrient tank, but you still have a deficiency because it is blocked by a Nitrogen toxicity).
- pH refers to the acidity or alkalinity of a solution and plants require a stable pH that balances out these two features. If the pH levels in your nutrient tank go off the mark, your plant will suffer, it will stop growing and it might even die.
The Basic Concepts Lighting Hydroponic Systems
- In order to grow at their maximum potential, each plant requires a certain amount of light. Plants are divided into three categories, from low and medium to high light plants. High light plants require up to 18 hours of light per day, whereas low light plants can do with around 10 hours.
- Plants use different temperatures from the color spectrum during their life. Most notably, they use blue light when growing and red or orange light when flowering. Your hydroponic system should have adequate lights to deal with these phases in a plant's life, if you want to grow it to its maximum potential.
- One of the best blue lighting sources for home hydroponic systems is a metal halide lamp.
- One of the best red lighting sources for home hydroponic systems is a high pressure sodium lamp.
The Basic Concepts Behind Growth Media in Home Hydroponic Systems
- Growth media must be nutrient free, so it doesn't interfere with the solution that you use in your nutrient tank (i.e. doesn't cause toxicity or deficiency with one or more nutrients).
- Growth media cannot contain any pH modifiers and it must have neutral pH (pH level 7).
- Growth media must retain water and air, but it must also drain quickly enough to be usable in flood systems such as the ebb and flow, or continuous drip.
The Basic Concepts Hydroponic Systems
- Instead of soil, we will be using water and a nutrient solution to grow the plant in
- A hydroponic system needs to find a balance between feeding and drowning plants
- A hydroponic system generally refers to every aspect involved in plant growth, ranging from the container to the growth media or the lighting system. In other contexts, a home hydroponic system can refer strictly to the method you're using to grow the plants with: ebb and flow, water culture, NFT, aeroponics and so forth.
The Basic Concepts Behind Nutrition in Home Hydroponic Systems
- Your plants need several nutrients, which are divided into two groups, primary and secondary. The primary group contains three elements, Nitrogen, Phosphorus and Potassium, whereas the secondary group contains over 20 elements, the most important being Calcium, Iron, Magnesium, Manganese, Zinc and Sodium.
- Too much of the same nutrient can develop a toxicity in your home hydroponic system's solution.
- Too little of the same nutrient can develop a deficiency in your home hydroponic system's.
- Some nutrients lock each other out, so by developing a toxicity in one nutrient, you automatically cause a deficiency in another. This is often problematic in finding the cause of a deficiency (i.e. You get a lot of Magnesium in your nutrient tank, but you still have a deficiency because it is blocked by a Nitrogen toxicity).
- pH refers to the acidity or alkalinity of a solution and plants require a stable pH that balances out these two features. If the pH levels in your nutrient tank go off the mark, your plant will suffer, it will stop growing and it might even die.
The Basic Concepts Lighting Hydroponic Systems
- In order to grow at their maximum potential, each plant requires a certain amount of light. Plants are divided into three categories, from low and medium to high light plants. High light plants require up to 18 hours of light per day, whereas low light plants can do with around 10 hours.
- Plants use different temperatures from the color spectrum during their life. Most notably, they use blue light when growing and red or orange light when flowering. Your hydroponic system should have adequate lights to deal with these phases in a plant's life, if you want to grow it to its maximum potential.
- One of the best blue lighting sources for home hydroponic systems is a metal halide lamp.
- One of the best red lighting sources for home hydroponic systems is a high pressure sodium lamp.
The Basic Concepts Behind Growth Media in Home Hydroponic Systems
- Growth media must be nutrient free, so it doesn't interfere with the solution that you use in your nutrient tank (i.e. doesn't cause toxicity or deficiency with one or more nutrients).
- Growth media cannot contain any pH modifiers and it must have neutral pH (pH level 7).
- Growth media must retain water and air, but it must also drain quickly enough to be usable in flood systems such as the ebb and flow, or continuous drip.
The History of Hydroponics
We were barely discovering flight in the early 20th century and 60 years later we were landing on the Moon. Nowadays, we're using hydroponics vegetable gardening systems to grow our fruit in nutrient solutions, but back then (gasp!) people were still using plain old dirt to do so. Which takes me to the point I wanted to discuss today, namely the rise to fame of this relatively new technology that has "future standard of living" written all over it: hydroponics vegetable gardening.
Early Roots of Hydroponics Gardening
The fact that the word "hydroponics" comes from the Greek language in which it can be translated as "working water" is not a coincidence, since the technology was first tried out in ancient Greece. Of course, the meaning of the word changed dramatically since then, but the concept of hydroponics vegetable gardening was similar: growing a plant in a medium that's different from soil. Similar hydroponics can be traced back into the Babylonian and Aztec civilizations as well, so we can't really say it's a Greek invention per se.
But the Greeks, Babylonians and Aztecs didn't do much with the hydroponics vegetable gardening technology. It was the Romans (who else?) that put it to good use at a larger scale, growing cucumbers off season around the first century AD.
Downfall of Hydroponics Vegetable Gardening Systems
Unfortunately, the new technology didn't prove a viable solution back then and it's not hard to understand why, given the structure of their society, based on traditionalism and plain old agriculture. Hydroponics vegetable gardening went into a downfall for 1,500 years, until the 1600s, when several European countries started seeing the benefits of growing vegetables off season and protecting them from cold, using rather primitive gardening systems. Although the scale at which these early hydroponics vegetable gardening systems were used was very small, it was the birth (or rebirth) of a technology that would become increasingly valuable over the next centuries.
The most common problem with 18th century gardening was not growing the plants to be more nutritious or large, but protecting them from cold and other environmental issues. Wooden frames covered with translucent paper were used to protect the plants or even straw mats and oiled paper, the latter being more common in Japan than Europe. These were the first steps towards modern hydroponics vegetable gardening systems, but the biggest breakthrough was yet to come…
The Revolution in Hydroponics Vegetable Gardening - Nutrient Solutions
Although soilless gardening was common by the 19th century, the main medium used was distilled water or different mixes that did little for the quality of the vegetables grown there. In the 1860s though, two German botanists, Wilhelm Knop and Julius von Sachs created the first mineral nutrient solutions, aimed at taking hydroponics gardening to the next level. And that they did, as the two soon proved that the vegetables grown in such a nutrient solutions would not only grow bigger and faster, but they would also be a lot healthier and nutritious.
Of course, the results weren't that spectacular back then as they are today. The first awe-causing vegetables are known to be grown by professor William Frederick Gericke of the University of California, in 1929. He experimented with various hydroponics vegetable gardening systems using a large array of nutrient solutions and in 1929 he created a sensation amongst the media and his fellow colleagues, by presenting them with an extremely large tomato (as well as several other vegetables) that he claimed was grown in his backyard.
Nowadays, hydroponics gardening tends to become a commodity, rather than some eccentric experiment. Arid countries such as Israel or parts of the United States thrive on this type of gardening and recently we can notice a trend in home based hydroponics. It's not far fetched saying that it shouldn't be long before hydroculture replaces a great deal of today's agriculture.
Early Roots of Hydroponics Gardening
The fact that the word "hydroponics" comes from the Greek language in which it can be translated as "working water" is not a coincidence, since the technology was first tried out in ancient Greece. Of course, the meaning of the word changed dramatically since then, but the concept of hydroponics vegetable gardening was similar: growing a plant in a medium that's different from soil. Similar hydroponics can be traced back into the Babylonian and Aztec civilizations as well, so we can't really say it's a Greek invention per se.
But the Greeks, Babylonians and Aztecs didn't do much with the hydroponics vegetable gardening technology. It was the Romans (who else?) that put it to good use at a larger scale, growing cucumbers off season around the first century AD.
Downfall of Hydroponics Vegetable Gardening Systems
Unfortunately, the new technology didn't prove a viable solution back then and it's not hard to understand why, given the structure of their society, based on traditionalism and plain old agriculture. Hydroponics vegetable gardening went into a downfall for 1,500 years, until the 1600s, when several European countries started seeing the benefits of growing vegetables off season and protecting them from cold, using rather primitive gardening systems. Although the scale at which these early hydroponics vegetable gardening systems were used was very small, it was the birth (or rebirth) of a technology that would become increasingly valuable over the next centuries.
The most common problem with 18th century gardening was not growing the plants to be more nutritious or large, but protecting them from cold and other environmental issues. Wooden frames covered with translucent paper were used to protect the plants or even straw mats and oiled paper, the latter being more common in Japan than Europe. These were the first steps towards modern hydroponics vegetable gardening systems, but the biggest breakthrough was yet to come…
The Revolution in Hydroponics Vegetable Gardening - Nutrient Solutions
Although soilless gardening was common by the 19th century, the main medium used was distilled water or different mixes that did little for the quality of the vegetables grown there. In the 1860s though, two German botanists, Wilhelm Knop and Julius von Sachs created the first mineral nutrient solutions, aimed at taking hydroponics gardening to the next level. And that they did, as the two soon proved that the vegetables grown in such a nutrient solutions would not only grow bigger and faster, but they would also be a lot healthier and nutritious.
Of course, the results weren't that spectacular back then as they are today. The first awe-causing vegetables are known to be grown by professor William Frederick Gericke of the University of California, in 1929. He experimented with various hydroponics vegetable gardening systems using a large array of nutrient solutions and in 1929 he created a sensation amongst the media and his fellow colleagues, by presenting them with an extremely large tomato (as well as several other vegetables) that he claimed was grown in his backyard.
Nowadays, hydroponics gardening tends to become a commodity, rather than some eccentric experiment. Arid countries such as Israel or parts of the United States thrive on this type of gardening and recently we can notice a trend in home based hydroponics. It's not far fetched saying that it shouldn't be long before hydroculture replaces a great deal of today's agriculture.
Friday 11 December 2009
What is hydroponics?
The word, Hydroponic, comes from Latin and means working water. Simply put, it is the art of growing plants without soil.
When most people think of hydroponics, they think of plants grown with their roots suspended directly into water with no growing medium. This is just one type of hydroponic gardening known as N.F.T. (nutrient film technique). There are several variations of N.F.T. used around the world and it is a very popular method of growing hydroponically. What most people don't realize is that there are countless methods and variations of hydroponic gardening. In this section, we explain the most common, including the pros and cons of each along with an abundance of great, general information about hydroponics.
Why does Hydroponics work so well?
That's simple. If you give a plant exactly what it needs, when it needs it, in the amount that it needs, the plant will be as healthy as is genetically possible. With hydroponics this is an easy task; in soil it is far more difficult.
With hydroponics the plants are grown in an inert growing medium (see below) and a perfectly balanced, pH adjusted nutrient solution is delivered to the roots in a highly soluble form. This allows the plant to uptake its food with very little effort as opposed to soil where the roots must search out the nutrients and extract them. This is true even when using rich, organic soil and top of the line nutrients. The energy expended by the roots in this process is energy better spent on vegetative growth and fruit and flower production.
If you grow two genetically identical plants using soil for one and hydroponics for the other, you will almost immediately see the difference this factor makes. Faster, better growth and much greater yields are just some of the many reasons that hydroponics is being adapted around the world for commercial food production as well as a growing number of home, hobby gardeners.
What is "growing medium"?
Growing medium is the material in which the roots of the plant are growing. This covers a vast variety of substances which include Rockwool, perlite, vermiculite, coconut fiber, gravel, sand and many more. The growing medium is an inert substance that doesn't supply any nutrition to the plants. All the nutrition comes from the nutrient solution (water and fertilizer combined). You can therefore, easily control everything the plants receive. The strength and pH of the nutrient solution is easy to adjust so that the plants receive just the right amount of food. The watering/feeding cycles can be controlled by an inexpensive timer so that the plants get watered on schedule, as needed.
What is the difference between hydroponic, organic and "regular" fertilizers?
Both hydroponic fertilizers and those intended for use in soil contain the three major nutrients, nitrogen, phosphorus and potassium. The major difference in hydroponic fertilizers is that they contain the proper amounts of all the essential micro-nutrients which fertilizers intended for use with soil do not. The plants are expected to find these elements in the soil, assuming that the trace elements are in fact present. Problems can arise for the plants if any or all of the micro-nutrients are not present in the soil or are depleted by successive (or excessive) plantings. Hydroponic fertilizers are usually in a more refined form with fewer impurities making them both more stable and soluble for better absorption. Organic fertilizers, in most cases, are very different than either hydroponic or soil fertilizers both in composition and how they deliver the nutrient to the plants. Organic fertilizers rely on the synergistic action of bacteria and microbes to break down nutritional substances for easier uptake by the plants. Hydroponic and soil fertilizers provide nutrients in a ready-to-use form. While once, they were mutually exclusive, in recent years a number of outstanding organic fertilizers have hit the market in formulations refined enough for use in hydroponics. For more information click on the excellent article below.
"Hydroponic or Organic-What's the Difference?" by Roger H. Thayer
What are micro-nutrients?
The micro-nutrients, also known as trace elements that are required for healthy plant growth are calcium, magnesium, sulfur, boron, cobalt, copper, iron, manganese, molybdenum and zinc. When deficient in any or all of these elements plants suffer stress, disease, become more susceptible to pest, fungus' and bacteria, and may have uptake issues with the N-P-K fertilizer they are being fed. At best, they will never live up to their genetic potential in growth and yield; at worst, they die. In the case of food crops, nutrient deficient plants lead to nutrient deficiencies in the people and animals who consume them. Due to years of over farming the same fields much of today's commercially produced food has a nutrient level barely exceeding waxed fruit. No surprise that more and more people are choosing to grow the food their families eat in their own gardens. When growing in soil remember to renew the dirt between plantings and when growing hydroponically know that it is absolutely essential to use a hydroponic fertilizer that provides all the trace elements.
How complicated is hydroponic gardening?
It can be but it doesn?t have to be. Hydroponics can be as incredibly simple as growing a single plant in a hand watered bucket or nursery pot, using any number of inert growing mediums. No automation, electricity or grow lights required.
Of course, the potential to go high tech is limited only by your imagination and budget. Virtually every aspect of garden management can be automated and should you so desire, monitored and controlled with your laptop or cell phone from the other side of the world. Dare to dream.
Most hobby oriented hydroponic systems are somewhere between the two extremes mentioned above. The average, home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a submersible pump to water the plants, a simple timer and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
Is pH important in hydroponics?
The control of pH is extremely important, not only in hydroponics but in soil as well. Plants lose the ability to absorb different nutrients when the pH varies. (This topic is answered in much greater detail in the "mini-class").
The ability to quickly and easily test and control pH in hydroponics is a major advantage over dirt gardening, where testing and adjusting the pH is much more complicated and time consuming.
When most people think of hydroponics, they think of plants grown with their roots suspended directly into water with no growing medium. This is just one type of hydroponic gardening known as N.F.T. (nutrient film technique). There are several variations of N.F.T. used around the world and it is a very popular method of growing hydroponically. What most people don't realize is that there are countless methods and variations of hydroponic gardening. In this section, we explain the most common, including the pros and cons of each along with an abundance of great, general information about hydroponics.
Why does Hydroponics work so well?
That's simple. If you give a plant exactly what it needs, when it needs it, in the amount that it needs, the plant will be as healthy as is genetically possible. With hydroponics this is an easy task; in soil it is far more difficult.
With hydroponics the plants are grown in an inert growing medium (see below) and a perfectly balanced, pH adjusted nutrient solution is delivered to the roots in a highly soluble form. This allows the plant to uptake its food with very little effort as opposed to soil where the roots must search out the nutrients and extract them. This is true even when using rich, organic soil and top of the line nutrients. The energy expended by the roots in this process is energy better spent on vegetative growth and fruit and flower production.
If you grow two genetically identical plants using soil for one and hydroponics for the other, you will almost immediately see the difference this factor makes. Faster, better growth and much greater yields are just some of the many reasons that hydroponics is being adapted around the world for commercial food production as well as a growing number of home, hobby gardeners.
What is "growing medium"?
Growing medium is the material in which the roots of the plant are growing. This covers a vast variety of substances which include Rockwool, perlite, vermiculite, coconut fiber, gravel, sand and many more. The growing medium is an inert substance that doesn't supply any nutrition to the plants. All the nutrition comes from the nutrient solution (water and fertilizer combined). You can therefore, easily control everything the plants receive. The strength and pH of the nutrient solution is easy to adjust so that the plants receive just the right amount of food. The watering/feeding cycles can be controlled by an inexpensive timer so that the plants get watered on schedule, as needed.
What is the difference between hydroponic, organic and "regular" fertilizers?
Both hydroponic fertilizers and those intended for use in soil contain the three major nutrients, nitrogen, phosphorus and potassium. The major difference in hydroponic fertilizers is that they contain the proper amounts of all the essential micro-nutrients which fertilizers intended for use with soil do not. The plants are expected to find these elements in the soil, assuming that the trace elements are in fact present. Problems can arise for the plants if any or all of the micro-nutrients are not present in the soil or are depleted by successive (or excessive) plantings. Hydroponic fertilizers are usually in a more refined form with fewer impurities making them both more stable and soluble for better absorption. Organic fertilizers, in most cases, are very different than either hydroponic or soil fertilizers both in composition and how they deliver the nutrient to the plants. Organic fertilizers rely on the synergistic action of bacteria and microbes to break down nutritional substances for easier uptake by the plants. Hydroponic and soil fertilizers provide nutrients in a ready-to-use form. While once, they were mutually exclusive, in recent years a number of outstanding organic fertilizers have hit the market in formulations refined enough for use in hydroponics. For more information click on the excellent article below.
"Hydroponic or Organic-What's the Difference?" by Roger H. Thayer
What are micro-nutrients?
The micro-nutrients, also known as trace elements that are required for healthy plant growth are calcium, magnesium, sulfur, boron, cobalt, copper, iron, manganese, molybdenum and zinc. When deficient in any or all of these elements plants suffer stress, disease, become more susceptible to pest, fungus' and bacteria, and may have uptake issues with the N-P-K fertilizer they are being fed. At best, they will never live up to their genetic potential in growth and yield; at worst, they die. In the case of food crops, nutrient deficient plants lead to nutrient deficiencies in the people and animals who consume them. Due to years of over farming the same fields much of today's commercially produced food has a nutrient level barely exceeding waxed fruit. No surprise that more and more people are choosing to grow the food their families eat in their own gardens. When growing in soil remember to renew the dirt between plantings and when growing hydroponically know that it is absolutely essential to use a hydroponic fertilizer that provides all the trace elements.
How complicated is hydroponic gardening?
It can be but it doesn?t have to be. Hydroponics can be as incredibly simple as growing a single plant in a hand watered bucket or nursery pot, using any number of inert growing mediums. No automation, electricity or grow lights required.
Of course, the potential to go high tech is limited only by your imagination and budget. Virtually every aspect of garden management can be automated and should you so desire, monitored and controlled with your laptop or cell phone from the other side of the world. Dare to dream.
Most hobby oriented hydroponic systems are somewhere between the two extremes mentioned above. The average, home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a submersible pump to water the plants, a simple timer and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
Is pH important in hydroponics?
The control of pH is extremely important, not only in hydroponics but in soil as well. Plants lose the ability to absorb different nutrients when the pH varies. (This topic is answered in much greater detail in the "mini-class").
The ability to quickly and easily test and control pH in hydroponics is a major advantage over dirt gardening, where testing and adjusting the pH is much more complicated and time consuming.
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