Indian family makes a breakthrough in hydroponics

by Mike Adams

Hydroponics, the practice of growing plants in water instead of soil, received a giant lift from a New Delhi family that created a purely organic nutrient mix that has sustained tomatoes and Arjun.

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An Indian hobbyist has created a purely organic nutrient mixture for growing plants in water. Although it is still an evolving science, hydroponic agriculture (growing plants in water solution rather than soil) is spreading fast the world over. The nutritional requirement of the plants in this system of soilless farming is met by the nutrient mixtures, called hydroponics fertiliser mixtures, added to the water in which the plant roots are kept submerged. These mixtures are made of chemical plant nutrients. A breakthrough has now been achieved by an Indian hydroponics hobbyist in creating a purely organic nutrient mixture for growing plants in water. This wholly chemical-free plant growth solution has been tested successfully for growing several plants, including common vegetables like tomato and arbi and some high value medicinal plants like Brahmi, Arjun and Cineraria. Indeed, a good deal of research is underway in this system of soilless farming in the US and Europe but not much headway has been made anywhere in organic hydroponics. Of course, some hydroponics enthusiasts abroad have been experimenting with various kinds of organic manures and mixtures of plants, but successful and commercially viable organic hydroponics models are still not available. His daughter, Shweta Singh, a Delhi University botany student, has been assisting him in discovering and further improving the biofertiliser mixture for growing plants in ordinary water. “I will work on it for a couple of years more before thinking of launching commercial production of this bio-fertiliser for hydroponics. However, if some government organisation, such as the Indian Council of Agricultural Research (ICAR), comes forward, I am willing to cooperate with it in promoting organic hydroponics in India,” he says. He believes that nearly 200 commercially important plants can be grown by hydroponics technique.

Source: Article taken from Natural News, only for information purpose

Hydroponic Fertilizer Solutions

Plants typically grow with their roots in soil and their stems and leaves in the air. They get some of the elements they require from the air (for example, most of the carbon and much of the oxygen used by the plant comes from the carbon dioxide taken in by the leaves of the plant), there are other nutrients that can be fed to them through their foliage, and there are even some aerial plants that get everything they need to thrive without any contact with soil at all. However, most plants get the bulk of what they need through their roots, usually in soil.

In a hydroponic production system, however, instead of getting nutrients from the soil, the plant derives the nutrients it needs from the solution in which its roots are immersed. A fertilizer solution is supplied to the roots, and the way the solution is supplied is important because it influences what components of the air, such as oxygen, are included.

Soil is avoided in specialized controlled-environment systems because it introduces so many composition variables and potential insect and disease problems. Soils differ from one part of a field to another and certainly from one part of the country to another, so fertilization according to soil becomes complex and tricky. Despite this, soil will continue to be the medium most used for agricultural plants for the foreseeable future.

Source Water

Water to be used in a hydroponic system should be tested before it is used. It is important to request an irrigation-water report rather than using a domestic-water report, because some elements critical to hydroponic growing will not be measured in a residential water test. Most water has a certain number of dissolved ingredients in it. In small quantities, most anything dissolved in the water is tolerable. If present in larger quantities, however, some plant-usable dissolved ingredients will require that the fertilizer solution be adjusted to include less of those ingredients.

Calcium and Magnesium

Calcium and magnesium are often present in source water in significant amounts. Calcium content in source water will range from almost nothing to more than a hundred or two parts per million (ppm). In a few groundwater samples it has been present in excess of 300 ppm, even higher than in most hydroponic fertilizer feed solutions. Magnesium’s presence in water can range from almost none up to 50 or 60 ppm. When magnesium is present at the higher levels, it’s likely that no magnesium will need to be added to the water in the hydroponic feed solution. Some ingredients that plants require, like manganese and boron, can be present in sufficient amounts to meet plant needs, but can sometimes be present in excess quantities. When these quantities are present, it is important to add little if any at all in the fertilizer program, since an excess of these substances can damage plants.

Sodium and Chloride

Other ingredients that are highly water-soluble, like sodium and chloride, are often present in groundwater as well as in surface water. Very small amounts of both sodium and chloride are used by plants. Larger quantities can make the water unusable for growing plants hydroponically. When the levels of either sodium or chloride approach 75 ppm in the water, some modifications in the use of the water for hydroponic production may be necessary. If both sodium and chloride are high in the water, plant production problems may develop even at levels lower than 75 ppm.

Sulphate

The sulphate ion is a combination of sulphur and oxygen that acts as a unit in water solutions and in many chemical reactions. It can be present in small to large quantities in source water. Although large quantities of the sulphate ion are tolerable in hydroponic solutions, a point comes when they are high enough in concentration that they don’t leave room in the solution for other needed fertilizer ingredients. Short of that, most plants havea fairly high tolerance for the sulphate ion in the fertilizer solution. Since most fertilizer ingredients are introduced to the hydroponic solution in the form of a salt, the tolerance for a little extra sulphate is a useful attribute in building a soluble fertilizer feed program.

Treating Source Water

When source water is not suitable for hydroponic plant production because of excessive levels of sodium, chloride, sulphate and/or other ingredients, the water can be made suitable for plant production by being processed through reverse osmosis equipment. Itis interesting to note that most growers find better plant production results when 10 to 25 per cent untreated source water is blended back into the treated reverse osmosis water. The amount of blend-back will depend on how much of the excess levels of elements are present in the source water.

 

Hydroponic Fertilizer Components

Although there may be different approaches to developing a fertilizer for hydroponic plant production, only the approach using soluble fertilizer concentrates that can be diluted will be outlined here. In the concentrated fertilizer solution, the calcium must be kept separate from the sulphates and phosphates, so two separate concentrate tanks are needed. Let’s start with the calcium source and look at other fertilizers that are compatible with it in the same solution.

Calcium

The only suitable soluble calcium salt for the concentrate solution is calcium nitrate. Although calcium chloride is soluble, we don’t want to use it because of the addition of the chloride ion. Some fertilizer formulators do use it up to the legal limit for the chloride level in a fertilizer, but even a small amount of chloride content in the fertilizer, combined with chloride that may be present in the source water, could overload the chloride content in the fertilizer program. Using chloride in the fertilizer solution would reduce the variety of source waters usable for hydroponic plant production.

The amount of calcium in your source water can be subtracted from the calcium target for the fertilizer. That level will differ in waters in various parts of the country. Surface water such as that from rivers or lakes will usually contain a low level of calcium, if any. Well water is more likely to contain significant amounts of calcium. That depends, however, upon the rock and other media it has gone through in the ground. This is why it is advisable to have a water analysis done so that you know the calcium and other content of the water. In the U.S., well water in Ohio and Michigan, for example, will usually contain significant to even high levels of calcium. By contrast, well water in Tennessee will usually not contain much of anything in the way of elements. Some of the nitrogen needed by the plants will be provided in the calcium nitrate.

Potassium, Phosphorus, and Nitrogen

Potassium sulphate is soluble and usable by plants and can be used in the fertilizer solution. However, it needs to be supplied in the sulfate concentrate tank. The fertilizer of choice is mono potassium phosphate, which is also soluble in water and is used as the source of any phosphorus needed in the fertilizer program. Mono potassium phosphate will need to be supplied in the sulfate concentrate tank as well. Although many growers use phosphoric acid as a source of phosphate, we do not recommend it because it is much easier to manage the fertilizer program if the fertilizer management and the pH management are separated. If a fertilizer containing acid such as phosphoric acid is used, the fertilizer program and the pH management program are tied together, so that a change in one will affect the other, making it much trickier to maintain proper levels of both nutrients and pH.

Once the target amount of phosphate has been determined for the fertilizer recipe, the amount of potassium present in the mono potassium phosphate is calculated and then subtracted from the potassium target, giving us a new target amount of potassium. The amount of potassium nitrate necessary to supply the needed potassium is then calculated. If that results in excess amounts of nitrogen, the potassium nitrate needs to be backed off so that the nitrogen target is not exceeded. When this happens, the potassium target is met by adding enough potassium sulphate to bring the potassium to the target amount.

If the nitrogen target has not yet been met with the calcium nitrate and the potassium nitrate in the fertilizer recipe, the calcium nitrate can usually be increased to meet the nitrogen target. The additional calcium is usually not a problem in the fertilizer program. Magnesium nitrate can also be used if there is room in the program for the nitrogen that would also be supplied.

Iron

In the fertilizer solution, iron is supplied in chelated form. The chelating molecule is a large molecule that surrounds the iron and prevents it from chemically reacting with other ions in the solution. This preserves it for uptake by the plant roots. The chelating agent does not interfere with the plant’s uptake of iron. A number of chelating agents are available. Because EDTA (ethylenediamine tetraacetic acid) is toxic to plants, some growers do not use any EDTA chelates in their recipes. DTPA (diethylenetriamine pentaacetic acid) is a more suitable chelating agent. It protects the iron over a broader pH range. It is a little more expensive than EDTA, but many growers consider the extra cost well worth it. The DTPA iron is best put into the calcium fertilizer concentrate tank. This keeps it separate from the manganese, copper, and zinc in the concentrate solution.

Magnesium

Magnesium is supplied in the sulphate tank. It is usually supplied through Epsom salts or magnesium sulphate. Epsom salts are not very expensive and are readily available. Magnesium can also be supplied in the nitrate form. For most fertilizer programs, however, the nitrogen target has been met by the time magnesium additions are being calculated, so magnesium nitrate is rarely used.

Micronutrients

In addition to the above main elements, micronutrients are also needed by plants, but in smaller quantities. These can be supplied in a concentrate mix that is then added to the sulphate fertilizer tank. Manganese, copper, and zinc can be supplied in the sulphate form. Some growers may use one or more of these nutrients in the chloride form, arguing that not much chloride is introduced to the fertilizer program from the comparatively small amount of micronutrient. Other growers use one or more of the nutrients in the EDTA chelated form. This is not a good idea for two reasons: 1) the EDTA is toxic to plants, and 2)the elements in chelated form can move around based on the preference of the chelating agent, making their distribution to the plants unpredictable. For this reason, using chelated manganese, copper, and zinc should be avoided.

Boron can be supplied using boric acid or solubor. Although solubor contains some sodium, the amount of sodium effectively added to the fertilizer solution is small because not much boron is needed. Molybdenum is usually supplied in either sodium molybdate or ammonium molybdate. A very small quantity of molybdenum is needed in the fertilizer solution, so the amount of sodium or ammonium supplied along with the molybdenum amounts to a small fraction of a part per million in the final fertilizer solution.

Fertilizer Solution Delivery

Reservoirs can be used in hobby greenhouses as a source of fertilizer solution for the plants. The feed-strength fertilizer is mixed from the concentrates every day or so and placed in the reservoirs. Although the reservoir can take up space in the greenhouse that could be used for growing plants, and it takes time every day or so to fill the reservoir with feed-strength fertilizer solution, this system requires a much lower investment than the use of fertilizer injectors.

Fertilizer injectors can be used to mix small amounts of the fertilizer concentrates and the pH adjustment concentrate with the incoming source water as it is delivered to the plants. There are several injector systems available. Some are pictured here. Systems can range in price from just over a thousand dollars to four or five thousand or more. The advantages of such systems include the opportunity to supply concentrates that need to be mixed less frequently than a reservoir would need to be filled. The injectors have adjustments that can be used to change the amount of fertilizer in the solution being fed.

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.

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 drawback 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.

WATER CULTURE

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. The biggest drawback of this kind of system is that it doesn't work well with large plants or with long-term plants.

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 soilless mix like Pro-mix or Faffard's).

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.

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.

AEROPONIC

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.