An Article on Chelated Nutrients

CONVERSATIONS ON CHELATION AND MINERAL

NUTRITION
Much has recently been said about mineral absorption into plants, and there are recent
pontifications that the best way to supplement minerals is to take "Colloidal" mineral
complexes, while still others professing that "Sulphates" are the way to go, and that
"Chelated" minerals are supreme due to their bioavailability.
Everything you hear has some ring of truth to it; each side has a point to make. But
unfortunately, neither side has ever told you the whole story about mineral uptake and
balance in plant nutrition, and the limits of all the above methods of mineral
supplementation. This has led to considerable confusion, misinformation and to the drawing
of many inaccurate conclusions. Can it be simplified? Perhaps gaining a better understanding
of what each category is may help reduce the confusion allowing growers to make a better
decision about what to use.

INORGANIC SALTS
These are simple mineral compounds such as sulphates or chlorides. Plants are accustomed
to dealing with minerals in this form, but don’t always do a good job of controlling
absorption. Although mineral absorption increases when there is a mineral shortage, and
decreases when mineral levels are high, the plants mineral transport system often misregulates
minerals that share the same transport channels. For example, when copper and
zinc salts are consumed together, they compete with each other for transport into the plant.
An excess of zinc can therefore cause a deficiency of copper. If one’s purpose in using
mineral fertilizers is to force the plant to use more minerals than it normally would, the
inorganic salts would be a poor choice. The rates of application for inorganic salts can be
quite high and the frequency of application is also frequent, therefore making the total cost
of inputs quite high over the growing season.

OXIDES
An oxide is a raw version of a mineral. For example, Iron Oxide is also known as “rust”.
How soluble is rust? Magnesium oxide is insoluble; however it is used in commercial
formulations as a source of magnesium. Oxides can only be dissolved using acids. The
availability of oxides is extremely low and these types of formulations are better used in soil
applications not as foliar sprays. Companies selling these formulations state that the product
is ground to a fine powder rendering it soluble or available. The texture of the product has
never been a criteria for the availability of any product. Only the formulation of the
product specifies its solubility and availability.

COLLOIDS (SUSPENSION FERTILIZERS)
Colloids are materials made up of solid particles of such small size that when dispersed in
water they remain in suspension rather than sinking. Colloidal minerals consist of mineral
salts or other mineral compounds converted into colloidal form, either by grinding or by
rapid crystallization.
Most colloidal substances are poorly bio-available, since the colloidal particles, small as they
are, are nevertheless far too large to be absorbed whole, and nearly all of the active
ingredients are trapped in the interior of the particles, where they cannot come into contact
with the transport channels in the cells. However, if a colloidal substance can dissolve, it
would then release all of its mineral material for potential absorption.

EDTA
EDTA or ethylenediaminetetraacetic acid is a novel molecule used for
complexing minerals. EDTA is a synthetic chelating agent which binds
to an element and is used in cosmetics, medicine and plant nutrition. It
is an agent which can not be utilised by the plant (never breaks down)
and binds to minerals such as Calcium very tightly and makes the
mineral less available once inside the plant. The complexed molecule is
large and enters mainly from the underside of leaf. Too much EDTA is
toxic to plants. EDTA is best used in pH’s below 7.

MIXTURES
Research has shown that chelated minerals are very important to plant nutrition; hence many
companies have rushed to the marketplace with their own brands of “chelated minerals”
without doing any research to determine whether or not their methods of chelation will
actually enhance the absorption of the mineral. The only objective of these companies is to
produce a “new” type of mineral fertilizer whereby their only objective is to gain profit from
calling their product a chelate.
Many products claim to be amino acid chelates, however when formulations are reviewed, it
is apparent that they are mixtures not chelates. The terms “chelate” and “amino acids” are
used very loosely. These products, of which there are many in the New Zealand marketplace,
are formulated by using protein powder and mineral salts, mixed together and the resulting
product is a mixture, but wrongly called a chelate. Mixtures tend not to carry patent numbers
as there generally is nothing to protect about the formulation. Mixtures are very expensive
for an imitation of a chelate.

ABOUT CHELATES
The word “chelator” refers to a substance consisting of molecules that bind tightly to metal
atoms, thus forcing the metal atoms to go wherever the chelator goes. The bound pair —
chelator plus metal atom — is called a “chelate”. Chelators of nutritional interest include
amino acids, organic acids, proteins, and occasionally more complicated chemicals found in
plants.

AMINO ACID CHELATES
Amino acids can act as chelators when they react with positively charged metal atoms,
forming a strong chemical bond. The metal atoms of interest here are those that serve as
minerals. To take a specific example, a chelate can be formed between the amino acid glycine
(the chelator) and calcium (the mineral).
Certain combinations of minerals and amino acids do not form good chelates because the
chemical bonding is too weak. For example, if you try to use the amino acid glutamic acid as
chelator and sodium as the mineral, you can get monosodium glutamate, which is considered
to be merely an “organic salt”, not a chelate. Generally speaking, sodium and potassium
form poor chelates.
Furthermore, amino-acid chelation bypasses the competitive interactions that can occur
between different minerals when they are absorbed as salts. Use of chelated minerals avoids
this problem since they are transported by different mechanisms.

THE AUTHENTIC CHELATES
The National Nutritional Food Association (NNFA) created a definition of what an Amino
Acid Chelate is in 1996;
Metal Amino Acid Chelate is the product resulting from the reaction of a metal ion from a soluble metal salt
with amino acids with a mole ratio of one mole of metal to one to three (preferably two) moles of amino acids
to form coordinate covalent bonds. The average molecular weight of the hydrolyzed amino acids must be about
150 AMU (Atomic Mass Units) and the resulting chelate must not exceed 800 AMU. The minimum
elemental metal content must be declared. It will be declared as a METAL amino acid chelate: e.g. Copper
amino acid chelate.
-Adapted by the NNFA Board of Directors, July 1996
For a true functional chelate, the following further requirements must be met:
1) The chelate must have a molecular weight less than 1000 daltons.
2) The chelate must be electrically neutral. The chelate must not be complexed with an easily
ionisable anion, such as a halogen or a sulfate group; the ligand must satisfy both the
oxidative state and a coordination number of the metal atom.
3) The chelate must have a high enough stability constant to avoid competitive chemical
interactions prior to absorption.
4) The ligand must be easily metabolised.



Chelated nutrients are more plant available than complexed nutrients (EDTA, EDDHA,
etc), and complexed nutrients are more plant available than mixtures and uncomplexed
nutrients (Quelant, Sulphates and Oxides) as can be seen in the table above.

COMMERCIAL AUTHENTIC CHELATES
An authentic chelate has all the properties specified above by the National Nutritional Food
Association (NNFA). There are two companies worldwide that actually carry patents for
manufacturing “authentic chelates” of which Glycine
technology is involved in both patented processes. What is
Glycine technology? It is a patented process of chelation
whereby every element is bonded with two Glycine (smallest
amino acid) molecules creating a fully chelated product. The
plant recognises this molecule as a protein like nitrogen,
allowing it to travel in the phloem quite readily to the
growing points such as flowers, fruit and berries where is it
required, as well as replenishing leaf levels also. This allows
the element to be a mobile element in the Glycine chelated
form whereas metals normally have low mobility within the plant. This is especially
important for elements like Calcium and Boron.
The Glycine technology methods of delivery are not conventional, like the delivery methods
of products such as oxides, sulphates and EDTA based trace elements. The latter products
can marginally reduce a deficiency, but the speed by which the elements are released from
these products and transported into the growing points is very slow compared to the
transportation of elements in the Glycine form.
How does one evaluate chelates against the other mineral forms in the marketplace
which also talk of availability?

Simply ask the following questions:
1) Does the product have a patent number?
2) What is the chelating agent in the product and what concentration is the chelate?
3) Are the minerals truly chelated to amino acids or just complexed or are they simply trace
minerals mixed with protein?
4) Is there proof of the chelate bond formation in the product?
5) Is the product stable when subjected to various pH ranges? (pH 4.0 - 7.5)?
6) Is the mineral product small enough in size to allow unhindered movement through the
plant?
7) Compare pricing. You may pay less for some reported chelates and complexes, but are
they really cheaper? If the product is not truly a chelate then you are essentially buying
inorganic minerals at a premium price. Without guaranteed availability, you lose two ways:
cost and mineral utilisation.

Only true amino acid chelates will give you your money's worth. Don't be fooled by
imitations.

Written by Asma Johansson (Horticulturist / Viticulturist) B.Sc. Agr (Hons)
Majoring in Viticulture and Plant Nutrition.

The Article basically says amino acid chelates are the best choice for nutrient delivery. The only Nutrient Company I can find that uses amino acid chelates is Humboldt Nutrients in their Master A&B line of Nutrients. Advanced Nutrients uses the EDTA process, as does General Hydroponics in their Floramicro Nutrients (along with EDDHA and DPTA). I'm Currently Using Advanced Nutrients Connoisseur A&B but I'm thinking I might try Humboldt Nutrients Master A&B Next, unless any of you can come up with a valid reason not to.

Another article I ran across in my research on chelating agents suggests adding fulvic acid to your nutrient solutions...

Fulvic acid is a biological chelating agent. It results from the decomposition of organic matter into humus, which
is microbially processed into humic acids, microbe's further process the humic acids to produce fulvic acid. Fulvic
acids are lighter in weight and more biologically active than their precursor, humic acids. Weighing between 7,000
to 70,000 Daltons, fulvic acids are very light when compared to their humic counterparts weighing up 700,000
Daltons. They are also much more biologically active. In simplest terms, humic acids are associated with the physical
characteristics of soil, and fulvic acids are associated more closely with the plants biochemical reactions influencing
the plants metabolism. It's a question of feeding the soil or feeding the plant. Fulvic acid forms a four-point
bond with the elements it chelates.

One of the greatest advantages in adding a biological chelate such as high quality fulvic acid to your nutrient solution
is that unlike the synthetic chelates likely present in your nutrients, the fulvic acid chain can be absorbed into
the plant. This is advantageous for several reasons. The principal benefit is that the mobility of some nutrients within
the plant increase. It is true that some elements required by the plant are used more quickly than they can be
transported. Leaf tip burn in lettuce appears as a result of a localized calcium deficiency. During warm weather
(often found in grow rooms), the plant uses calcium faster than it can be transferred to the growing points, resulting
in a deficiency although calcium is being taken up at the roots. With the addition of fulvic acid, the calcium is
encapsulated by the fulvic acid chain, and will move more freely, thus reducing the incidence of tip burn.
Where fulvic acids really shine is when the growing environment in the root zone (rhizosphere) becomes above or
below optimal. The chelating and transport ability of fulvic acid in high or low pH and TDS ranges is affected very
little in comparison to the synthetic counterparts such as EDTA. Plants supplied a nutrient diet containing fulvic
acid are far less likely to exhibit signs of deficiency or stress during adverse conditions than plants supplied a diet
without fulvic acid. Not only does fulvic acid improve the transport of fertilizer minerals within the plant, but it also
helps to transport other plant fluids more efficiently, including those responsible for terpines (smell and flavour) and
resin production. Here is a tip: lightly spray high quality fulvic acid on the plants one week prior to harvest. Apply
only once. You should see a tremendous increase in the appearance of plant resins. This works wonderfully for all
those dedicated to growing the highest quality herbs.

Like the synthetic chelates, not all fulvic acids are equal in their effectiveness. Lets say you had two bottles of fulvic
acid and they both contained 100 chains of fulvic acid. If bottle "A" had a higher percentage of lighter weight
molecules, say between 7000 to 12,000 Daltons it would be much more effective than bottle "B" containing a higher
percentage of molecules in the 12,000 to 50,000 Dalton size range. The percentage of light weight molecules
is largely determined by the source of raw materials and the processe(s) used for extraction.

From - The Science behind Chelates, by Erik Biska

Anyway, Food for thought Ents.

Cheers,
Acidking

Straight to the point and very helpful! Thanks a lot for the info! How did the Humboldt nutrients treat ya? I'm finding the General Organics line to completely kick ass!

orazine said:

Straight to the point and very helpful! Thanks a lot for the info! How did the Humboldt nutrients treat ya? I'm finding the General Organics line to completely kick ass!

Click to expand...

I cant speak for the general organic lines but there other products have cancer warnings in the msds sheets. Humboldt nutrients have no warnings at all. Always look at the msds sheets first its what their there for and most people don't even know but then some organic freaks ( not referring to you in any way) will only buy products that are omri approved which in the scheme of things really doesn't mean much. Great article by the way. http://humboldtnutrients.com/wp-content/uploads/MSDS/MasterA.pdf http://generalhydroponics.com/site/gh/docs/prod_msds/FloraDuoA.pdf http://www.advancednutrients.com/hydroponics/msds_sheets/Connoisseur_Part_A_pH-Perfect.pdf I tend to stay away from genral hydroponics even though they wrote an awesome article on the craziness of organics in the 90S and how the usda and omri had to eventually step up and regulate organic terms. I personally think organics and the people who will only use organics are still pretty batshit.

The only ingredient that really needs to be chelated is the iron, and this is only if you're using a liquid nutrient rather than dry salts and mixing every batch.

The problem with iron sulfate is that it's very hard to dissolve in water, and doesn't mix with anything and tends to precipitate out.

I use iron sulfate myself, but it has nothing to do with health concerns. I'd use iron EDTA if i really wanted to mix iron into a stock solution, but I'm fine having it separate.

Other than that, there aren't any other ingredients that you really need to have chelated. Keep in mind that EDTA only binds to calcium if it doesn't have something already bound to it. Something like iron EDTA is only a problem if there's free EDTA left. Either way, the amount is so small in comparison to the amount of calcium there is.