Waaay Beyond Just Organic
Soil Minerals and Soil Testing for Organic Gardeners

The Minerals listed here are covered on this page, in this order.  Scroll down or click on the link below.












The Function of Soil Minerals and Trace Elements in Soil, Plant, Animal, and Human Nutrition and Health

Copper and Zinc


Copper (Cu) is element number 29 on the Mendeleeyev chart, the Periodic Table of the Elements.

The other elements in Copper's specific group (group 1B, directly below it on the table) are Silver (Ag) and Gold (Au), which puts it in some racy company.

Copper is the key to elasticity in the plant.  It is an important constituent of many proteins like ascorbic acid oxidase, cytochrome oxidase, diamine oxidase, and polyphenol oxidase.  Copper is an important nutrient for many microbes, such as Aspergillis niger.  It controls molds and often alleviates perceived zinc deficiencies.  Copper interacts with iron and manganese.   Andersen Science In Agriculture p236

Bordeaux mixture and Burgundy mixture are two famous sprays used to control fungus in vineyards. Developed in their eponymous provinces of France, Bordeaux mix is copper sulfate, mason's lime (calcium hydroxide), and water; Burgundy mix is copper sulfate, sodium carbonate (washing soda), and water.  The full recipes and instructions for using Bordeaux and Burgundy mixtures are given below in the section borrowed from the Copper Development Association's web site.

The story goes that Bordeaux mixture was discovered by accident.  During a wet fall in the province of Bordeaux in the 1880s the grapes were being severely attacked by downy mildew.  Along a road that ran past one vineyard, the owners had sprayed a mixture of copper and lime on the vines, which turned the grapes a blue green color and was meant to dissuade the passersby from picking the grapes.  The French scientist Millardet, while walking along, noticed that those vines were not being attacked by the fungus, and Bordeaux mixture was born.

As a part of of Bordeaux mixture in grape arbors, it functions as a nutrient and not as an insecticide as is often believed.  Walters, Eco-Farm   p136 [Copper's use in Bordeaux mixture is actually as a fungicide, not an insecticide, but we'll allow Charles Walters the occasional typo.  This observation should actually be credited to William Albrecht, who theorized that the copper in the mixture was stimulating the plant's immune system.]

Copper, vitally important to root metabolism, helps form compounds and proteins, amino acids and a host of organic compounds.  It acts as a catalyst or part of the enzyme systems.  It helps produce dry matter through stimulation of growth, prevents development of chlorosis, rosetting and dieback.  Walters Eco-Farm p 197

The role of organic matter in Cu chemistry is also indicated by analysis of the soil solution.  More than 99% of the Cu in the soil solution is complexed by organic matter.  This complexing is of great importance in maintaining adequate Cu in solution for plant use. Foth and Ellis Soil Fertility p141

Because Cu is not translocated in the plant, the deficiency symptoms appear on the new growth.  In small grains and corn the leaves appear olive or yellowish green in color, and often the leaves fail to unroll as they emerge.  Often the leaf tips will appear as though the plants have been frost-damaged, and there will be some flags.  A flag is is a wilted or dead leaf or a branch with such leaves on an otherwise healthy appearing plant.  Soil Fertility p157

Sul-po-mag, [also known as K-Mag and Langbeinite] applied between July 15 and September 15 up to 200 lbs per acre, seems to help in copper availability. Science in Agriculture p236  [K-Mag is available from HERE]

Copper in Human and Animal Health

An excess of copper results in degeneration of the liver.  It causes blood in urine and poor utilization of nitrogen.
A deficiency of copper is created by excess of molybdenum and cobalt.  It produces anemia due to poor iron utilization.  It depresses growth.  Other symptoms...depigmentation of hair and abnormal hair growth;  impaired reproductive performance and heat failure; scouring, fragile bones; retained placenta and difficulty in calving; and muscular incoordination in young lambs, and stringy wool. Walters Eco-Farm p367

...a largely vegetarian diet lacks the fat-soluble catalysts needed for mineral absorption.  Furthermore, phytates in grains block absorption of calcium, iron, zinc, copper and magnesium.  Unless grains are properly prepared to neutralize phytates, the body may be unable to assimilate these minerals. Fallon and Enig Nourishing Traditions p27

Ragweed, for example, is generally indicative of a phosphate/potash imbalance, but, more specifically, it indicates a copper problem.  Copper is important in the use of manganese and iron, as well as in many metabolic reactions,  Copper also seems to be important in controlling fungal disorders.  Many people have allergic reactions to ragweed pollen.  This reaction seems to be related to a copper deficiency in the mucous membranes. Andersen  Science In Agriculture P.192

Copper: Needed for the formation of bone, hemoglobin and red blood cells, copper also promotes healthy nerves, a healthy immune system and collagen formation.  Copper works in balance with zinc and vitamin C.  Along with manganese, magnesium and iodine, copper plays an important role in memory and brain function.  Nuts, molasses and oats contain copper but liver is the best and most easily assimilated source.  Copper deficiency is widespread in America.  Animal experiments indicate that copper deficiency combined with high fructose consumption has particularly deleterious effects on infants and growing children. Nourishing Traditions p43

Many enzymes incorporate a single molecule of a trace mineral-- such as manganese, copper, iron or zinc-- without which the enzyme cannot function.  Nourishing Traditions p46

Graeme Sait:  Can you revert grey hair with copper supplements?  I've had grey hair since I was twenty-five.
Joel Wallach:  It's definitely a Copper deficiency, and you could revert to your former hair color if you addressed the problem.  I see it every day with my clients.  It can be quite humorous when a seventy year old grey-haired man returns to his former redheaded glory.  Sait, Nutrition Rules p297

In Australia it was discovered that black sheep grazing on copper-deficient pastures turned gray.

In humans copper is stored in the liver.  In cases of fever and infection, the level of iron in the bloodstream drops and the blood copper level rises as the copper reserves in the liver are mobilized to aid the immune system in fighting off invaders.  This tidbit is from Andre Voison's classic Soil, Grass, and Cancer , in which the French bio-chemist and veterinarian devoted several chapters to the role of copper in human and animal health.

In the 1930s Dr. Weston A. Price investigated the traditional diets of isolated peoples around the world.  High in the Andes mountains of South America he discovered the native peoples relied on dried fish eggs and seaweed brought from the ocean to supply trace minerals and other factors lacking in their diet.  He writes "The kelp provided a very rich source of iodine as well as copper, which is very important to them in the utilization of iron for building an exceptionally efficient quality of blood for carrying oxygen liberally at those high altitudes. W. A. Price, Nutrition and Physical Degeneration p 265

Copper functions in the body as an enzyme co-factor, formation of hemoglobin and red blood cells, protein metabolism, synthesis of phospholipids, vitamin C oxidation, production of elastin, and formation of RNA.  Signs of possible deficiency are white hair, liver cirrhosis, allergies, parasites, hernia, anemia, hyper/hypo thyroidism, arthritis, ruptured disc and iron storage disease.  Walters, Minerals for the Genetic Code p122.

Zinc and copper have a seesaw relationship in the body, competing with each other for absorption in the gut.  Both zinc deficiency and copper toxicity have increased since the switch from zinc (galvanized) to copper water pipes.  We can avoid this problem by not drinking tap water.  Haas, Staying Healthy with Nutrition p191

The following wealth of information is from the Copper Development Association's web site at CDA Web Site

Uses of Copper Compounds: Copper Sulphate's Role in Agriculture

Copper sulphate has many agricultural uses but the following are the more important ones:

  • Preparation of Bordeaux and Burgundy mixtures on the farm

  • Control of fungus diseases

  • Correction of copper deficiency in soils

  • Correction of copper deficiency in animals

  • Stimulation of growth for fattening pigs and broiler chickens

  • A molluscicide for the destruction of slugs and snails, particularly the snail host of the liver fluke

Preparation of Bordeaux and Burgundy Mixtures on the Farm

Because of their importance to farmers, instructions concerning the dissolving of copper sulphate and the preparation of both Bordeaux and Burgundy mixtures have been included in the text.

Dissolving Copper Sulphate

Iron or galvanized vessels must not be used for the preparation of copper sulphate solutions. Plastic vessels, now freely available, are light and very convenient. To make a strong solution, hang a jute sack of copper sulphate so that the bottom of it dips a few inches only in the water. The copper sulphate will dissolve overnight. Copper sulphate dissolves in cold water to the extent of about 3 kg per 10 litres. If more than this is placed in the sack described above, then a saturated solution will be obtained and it may be used without serious error on the basis that it contains 3 kg copper sulphate per 10 litres.

Preparation of Bordeaux Mixture

Bordeaux mixture is prepared in various strengths from copper sulphate, hydrated lime (calcium hydroxide) and water. The conventional method of describing its composition is to give the weight of copper sulphate, the weight of hydrated lime and the volume of water in that order. The percentage of the weight of copper sulphate to the weight of water employed determines the concentration of the Bordeaux mixture. Thus a 1% Bordeaux mixture, which is the normal, would have the formula 1 :1:100the first 1 representing 1 kg copper sulphate, the second representing 1 kg hydrated lime, and the 100 representing 100 litres (100 kg) water. As copper sulphate contains 25% copper metal, the copper content of a 1% Bordeaux mixture would be 0-25 % copper. The quantity of lime used can be reduced considerably. Actually 1 kg copper sulphate requires only 0.225 kg of chemically pure hydrated lime to precipitate all the copper. Good proprietary brands of hydrated lime are now freely available but, as even these deteriorate on storage, it is safest not to exceed a ratio of 2:1. i.e. a 1:0.5:100 mixture.

In preparing Bordeaux mixture, the copper sulphate is dissolved in half the required amount of water in a wooden or plastic vessel. The hydrated lime is mixed with the balance of the water in another vessel. The two "solutions" are then poured together through a strainer into a third vessel or spray tank.

[Note from  It appears from the above that one doesn't want to mix the lime solution with the copper solution until one is ready to spray, as the lime precipitates the copper.  Well, that makes sense; copper sulfate is acid, calcium hydroxide is alkaline, mix them together and what happens?  You probably get calcium sulfate (gypsum) and copper oxide.  Copper oxide  is not water soluble.]

Preparation of a 1% Burgundy Mixture

Dissolve separately 1 kg copper sulphate in 50 litres water and 125 kg washing soda (or 0.475 kg soda ash) in 50 litres water and slowly add the soda solution to the copper sulphate solution with stirring. Control of fungus diseases

Bordeaux and Burgundy mixtures have been found effective in controlling a whole host of fungus diseases of plants. Normally a 0.5 % to 1 % Bordeaux or Burgundy mixture applied at 2 to 3 week intervals suffices to control most copper-susceptible fungi.

Generally once the fungus spores have alighted on the host plant and penetrated the tissues it is difficult to control them. The principle of control must in most cases depend on protection, ie preventing the fungus spores from entering the host tissues. Copper fungicides are noted for their tenacity and for this reason are much to be preferred in areas of high rainfall.

The simplest method of control is to apply a protective coating of Bordeaux or Burgundy mixture (or other copper fungicide) to the susceptible parts of the plant, so that spores alighting on them come in contact with the protective film of copper and are killed instantly. It is thus important to remember that the first spraying must ideally be made just before the disease is expected and continued at intervals throughout the susceptible period. For this reason it is important to take advantage of the early warning schemes which are in operation to ensure greater accuracy of the timing of the first spraying.

It must also be remembered that fungi are plants and that control measures that will kill them may not always leave the host plant unaffected. The use of too concentrated a fungicide mixture must therefore be guarded against, particularly for the early sprays.

Copper fungicides have been reported effective against numerous plant diseases. A list, by no means exhaustive, of some 300 diseases that have been found amenable to control by copper fungicides. [ note: the list is at the CDA web site ]

Correction of Copper Deficiency in Soils

Where copper deficiency has been confirmed by soil analysis or field diagnosis, whether in plants or animals, it can be corrected very simply either by applying 50 kg copper sulphate per hectare in the form of a fertiliser before sowing or by spraying the foliage of the young cereal plants, when they are about 150 mm high, with 750 grams copper sulphate (dissolved in from 400 to 2,000 litres water) per hectare. The soil application has generally given the better results and has the advantage that it may have a residual effect for more than ten years. The foliar application has to be given annually to each crop. An alternative is to add a copper containing slag (normally about 1% to 2 % copper) at a rate of a tonne to the hectare.

[Note from  50kg per hectare of copper sulfate works out to about 5-6 ppm of elemental copper]

Correction of Copper Deficiency in Animals

A method of correcting copper deficiency in livestock is to treat the soil on which animals graze. For example, in Australia and New Zealand swayback in lambs is being prevented by top dressing copper deficient pastures with 5 to 10 kg copper sulphate per hectare some time before lambing begins.

Other methods include drenching periodically with a copper sulphate solution; incorporating copper sulphate in salt and other animal licks; or by what is probably the most general method, incorporating copper sulphate along with other minerals and vitamins in the form of carefully blended supplements in the feeding stuffs.

Stimulation of Growth for Fattening Pigs and Broiler Chickens

The inclusion of up to as much as 0.1% copper sulphate in the diet of bacon and pork pigs and broiler chickens stimulates appetite and produces increased growth rate with a marked improvement in feed conversion.

A molluscicide for the destruction of slugs and snails, particularly the snail host of the liver fluke. All likely habitats of the liver fluke snail should be treated with copper sulphate at the rate of 25 kg to the hectare at least twice a year in June and August (northern hemisphere) or December and February (southern hemisphere).

End of info from CDA web site carries Copper in the form of Copper Sulfate, containing 25% Cu. It is highly water soluble for use as a soil amendment, a foliar spray, a fertilizer ingredient, or for making Bordeaux or Burgundy mixtures as described above.


First we hear from Arden Andersen, who thinks zinc is overused in agriculture:

Zinc is an essential component of many enzymes in the dehydrogenase, proteinase, and peptidase groups.  It is a minor catalyst for sul-po-mag and copper and is correlated closely with copper and active nutrient systems.  Zinc helps to make acetic acid in the root to prevent rotting; it is used to control blight and allows dead twigs on trees to shed off.  Perceived zinc deficiency is often only symptomatic.  Research has indicated that known soil-zinc deficiencies result in symptoms of plant-zinc deficiency only about 50% of the time.  Zinc is much overused and promotes the growth of many weed species.  Andersen Science in Agriculture p238

And next from Gary Zimmer, who appears to be a big fan of Zinc, particularly for corn/maize:

Zinc-- contributes to test weight, increased corn ear size, promotes corn silking, hastens maturity, chlorophyll formation, enzyme functions, regulates plant growth. Zimmer The Biological Farmer p109  [Zimmer also writes that zinc is "essential for corn starters" and recommends 5lbs/acre of 35% zinc to supply a corn crop and build soil levels.]

And a few more experts weigh in on zinc:

Charles Walters says that zinc "may act in the formation of chlorophyll.[....]It certainly stimulates plant growth and prevents the occurrence of mottled leaf in citrus, white bud in corn, and other disorders."  He further states that "Plants do require it in the 3-100ppm range." and regarding animal health that "An excess of zinc means decreased copper availability and interference with utilization of copper and iron, bringing about anemia.  A zinc excess also shows up as bald patches and skin disorders (rough skin), a deficiency is created by excess of calcium. Zinc is absolutely essential for production of sperm.  It also increases the need for vitamin A."  Walters Eco-Farm p366.

Now a word from the more mainstream guys: " ...zinc uptake by plants declines as pH increases.[....] High levels of phosphorus in soils has been known to intensify zinc deficiency in a number of crops. The exact cause of the zinc-phosphorus antagonism has been difficult to determine....the zinc-phosphorus antagonism occurs on calcareous [high calcium] soils and may be related to iron availability."  Foth and Ellis Soil Fertility p142  They also show an increase from 4.2 to 19.9 bushels per acre of pea beans on one field after the addition of 25lbs/acre of zinc, quite the boost.

Here's a fun one from an interview with Klaas Martens in Graeme Sait's Nutrition rules.  "...we need to lift our zinc levels as our phosphorus levels increase. We always need to use zinc with our starter fertilizers.  At one time, our consultant suggested that we had a zinc deficiency, simply by driving past one of our fields.  He didn't need a soil test, because the presence of milkweed was an indicator of a zinc shortage.  We've actually seen the milkweed disappear as we have slowly corrected the zinc."

The area of South-central Washington state known as the Palouse is one of the world's great wheat growing regions.  When it was first broken to the plow the production was tremendous, but by the 1920s it had fallen dramatically.  The problem turned out to be zinc insufficiency.  Zinc is easily water soluble, and this fact combined with low initial reserves of zinc in many soils has made zinc deficiency common.  It was also one of the earliest trace mineral deficiencies discovered, and its sometimes dramatic effect on crop yields has led to some overuse; one book in front of me lists the results from application of 122lbs/acre of zinc!  The results were quite disappointing, understandably. 

Both zinc and copper are well known for their need in animal nutrition, and most commercial livestock producers supplement animal feed with these minerals.  For that reason, manures from commercial livestock operations are frequently very good sources of zinc and copper (and sometimes boron). The problem with these manure sources of minerals is that one doesn't know how much they are getting, or what else they may be getting that they don't want.  See the article Minerals and Manure.

Moving on to the human nutrition aspect, the adult human body contains about 2400 milligrams of zinc.  Zinc is most concentrated in the male prostate and semen.  The next most concentrated tissues are the retina of the eye, the heart, spleen, lungs, brain, and adrenal glands.  Because of zinc's role in RNA and DNA synthesis and in the formation of many enzymes, zinc deficiency leads to slow healing of wounds.  In some hospital tests zinc supplements led to surgical incisions healing in one-half the "normal" time.  Zinc is important to normal insulin activity, the functions of taste and smell, normal immune function, protein digestion, and the formation of bones and teeth as it is a co-factor of alkaline phosphatase.  Fallon and Enig, in Nourishing Traditions , call zinc the "intelligence mineral".  It is generally more easily absorbed from animal products than from plants and although grains may contain significant zinc, that zinc may be bound up by the phytates in the grain's outer portion.  Many traditional peoples soaked and sprouted seeds and grains before cooking them, a practice that reduces or eliminates this mineral-binding by phytates. Fallon and Enig add "Even a minor zinc deficiency in pregnant animals results in offspring with deformities, such as club feet, cleft palates, domed skulls and fused and missing ribs.  In humans, zinc deficiency can cause learning disabilities and mental retardation."

Some of the other human nutritional and health problems associated with zinc deficiency are acne, boils, psoriasis, gastric ulcers (zinc is needed to form digestive acids), cataracts, hypertension, infertility, loss of or poor functioning of the senses of hearing, taste, and smell, weak muscles, and fatigue.

The brilliant British researcher Mark Purdey, in his groundbreaking work with mad cow disease and chronic wasting disease, found in a worldwide survey that both mad cow and CWD were strongly associated with soils that had very low levels of zinc and copper, combined with high levels of manganese and sometimes high levels of strontium and silver.  In those conditions copper in the melanin granules, which are transmitters of outside information to the brain, may be replaced by manganese with disastrous results. In other words, neither mad cow disease nor chronic wasting disease are caused by infectious microbes, but are the result of a mineral imbalance. For more info on Mark Purdey's important work see his web . carries Zinc in the form of Zinc sulfate, a purified soil amendment containing 35.5% Zinc and 17% Sulfur.  It is water soluble and is easily used for soil applications, fertilizer mixes, or foliar feeding.

Iron and Manganese


Iron is second only to aluminum in the list of abundant metals.  It makes up about 5% of the earth's crust, so it is rarely absent from soils, although it may not be present in an available form.

For garden soil we like to see 50-200ppm of iron on a standard soil test.  Above 250 ppm usually indicates something out of balance.

What does iron do in the plant?  Paraphrasing Arden Andersen, "Iron draws energy to the leaf by absorbing heat from the sun; it makes the leaf darker, thus absorbing more energy. It will increase the waxy sheen of the crop.  Iron is necessary for the maintenance and synthesis of chlorophyll and RNA metabolism in the chloroplasts.  It increases the thickness of the leaf, [which] increases nutrient flow geometrically, resulting in a production increase geometrically."  Science in Agriculture p236

Iron is needed by nitrogen fixing bacteria.

So iron is a good thing, in most cases. Below we have a couple of different views on just how good it is and how much we want:

Both iron and manganese become less available at pH 7 and above and in the absence of organic matter and water.  These conditions are found in some arid parts of the western United States.  High calcium soils also tend to have low available iron, particularly if they are also low in organic matter. In a calcareous soil, most of the potentially available iron is tightly bound to organic matter. Some plant roots have been shown to have the ability to obtain iron from these sources by chemically reducing ferric iron (Fe+++) to ferrous iron (Fe++).  High phosphorus soils may also have low available iron, as any free iron will chemically bind to from iron phosphate....Correcting an iron deficiency may be difficult because the problem is not a lack of iron in the soil, but that it is chemically bound.  Lowering the pH, if practical, is the surest method.  Foliar iron sprays are also effective. Foth and Ellis Soil Fertility pp146-147

Here's an excerpt from an interview with Gary Zimmer "In our dairy work we are looking at phosphorus as a key element.  We want phosphate uptake for sugars and energy and digestibility and plant health.  If I have high iron in my soils, usually from over-tillage, excessive use of caustic materials or too much nitrogen use, I'm not happy.  On a dairy farm, I scream and holler if they buy a single pound of commercial nitrogen.  If they buy nitrogen, I want to know why.  They had better use their manures and alfalfa and rotation, because I don't want iron buildups.  Iron binds with phosphate within the plant .  Many people who don't feed cattle don't notice this difference.  You see, the phosphorus may be in the plant, but when you bind it to iron, it becomes unavailable.  Iron has a triple-positive charge and phosphorus has a triple-negative charge, so they will bond very easily.  If your feed is high in iron, then the cow is starved for phosphorus.  We are fanatical about trying to get our iron down, just so we have better phosphate availability .  In high iron soils I don't think our soil tests give an accurate idea of phosphate availability to the plant." [emphasis added] Graeme Sait Nutrition Rules pp187-188.  Gary Zimmer works mostly with neutral or alkaline pH soils in the upper Midwestern US, and we don't know offhand what he considers high iron.

The info above brings up some interesting questions about iron supplements in general, don't you think?  I wonder what connection there might be between the high iron intake recommended for women and high incidences of osteoporosis?  Fallon and Enig have this to say about one type of iron supplementation "Recently, researchers have warned against inorganic iron used to supplement white flour.  In this form, iron cannot be utilized by the body and its buildup in the blood and tissues is essentially a buildup of toxins.  Elevated levels or inorganic iron have been linked to heart disease and cancer." Nourishing Traditions p44.

Charles Walters has this to say about signs of iron deficiency in plants "When iron deficiency is serious, the entire leaf will turn yellow, leaving only the veins to stand out like road maps....Chlorosis (white leaves that should be green) is possible even in the presence of iron.  Lime can complex iron, and yet in the human being calcium and copper must be present for iron to function properly.  In order to free iron, the farmer must complex calcium in this case, and this means using either iron sulfates or iron chelates, or substituting a proper foliar blend." Eco-Farm p196.

At soil we have seldom seen a soil test that showed a lack of iron. and as we usually are working with gardens and fields of a few acres and smaller, our approach is to bring the pH down below 7 which will make iron (as well as the other cations) more easily available.  The alternative, if one cannot lower the pH with minerals because of size, expense, highly calcareous soils, or other constraints, is to increase the biological activity in the soil.  As noted above in the excerpt from Foth and Ellis' Soil Fertility, in a calcareous soil most of the iron is tied up with organic matter.  Increasing the organic matter content of such soils will provide more holding points for iron, and increasing the biological activity, through the addition or seeding of beneficial bacteria and fungi, should make more Fe available to the plants. carries Iron in the form of Iron sulfate, a purified soil amendment containing 30% Iron and 17% Sulfur .  It is water soluble and is easily used for soil applications, fertilizer mixes, or foliar feeding.


Manganese is synergistic with iron; they work together in biology in ways that are not well understood, but we do know that they need each other.  Good steel must have some manganese in it to impart toughness, and that manganese in the steel also absorbs oxygen during the steel making process.  Perhaps this is a clue to the biological relationships of Mn and Fe, in that the manganese may slow the oxidation rate of iron in living things.

We at like to see about 1 part manganese to 2 parts iron on soil test results, up to about 50 ppm manganese.  Levels above 50 ppm may be too high, particularly if the soil is deficient in copper and zinc.  In wet, acid soils below pH 5 or so that naturally contain high amounts of manganese, soluble manganese can reach levels that are toxic to plant roots.  The remedy for these conditions would be to drain the soil better, or, if the crop requires a wet, acid soil (e.g. cranberries), the remedy would be to increase water flow through the soil, as more water will bring more oxygen, which will precipitate the excess manganese in an insoluble state.

Arden Andersen calls manganese "the element of life", and says that manganese "brings the electrical charge into the seed, creating the magnetic force to draw the other elements into the seed." (Science in Agriculture p236.) In Eco-Farm, Walters  credits manganese with with aiding the oxidase enzyme in carrying oxygen, and  entering into the oxidation and reduction reactions needed in carbohydrate metabolism and in seed formation; more clues that manganese has a strong connection with oxygen.  Regarding manganese in animal nutrition, Walters tells us that an excess of manganese increases the need for iron, while a manganese deficiency results in leg deformities in calves, eggs not formed correctly, degeneration of testicles, offspring born dead, and delayed heat periods, and also says that an excess of calcium and phosphorus may lead to a manganese deficiency. (Eco-Farm p366)

We definitely know that manganese is necessary for the development of viable seeds.  The most common and obvious sign of manganese deficiency is in the almond family. Peaches, nectarines and apricots with split-open pits containing a shriveled seed are the prime example.  Dan Skow has some interesting insights on this from the Carey Reams school of thought: "If there is no Manganese in the seed, it will swell up and rot [rather than sprouting].  Manganese has a high atomic weight, 54.9380, meaning it has more power than nutrients in the surrounding soil. [Manganese] puts into play the magnetism necessary to draw nutrients into the seed to feed it and its emerging root system.  When there is a shortfall for manganese, the entire fertility program has to be adjusted to create enough energy to pull more manganese."  ( Mainline Farming for Century 21p59.)  Skow recommends a foliar spray of manganese mixed with phosphoric acid to easily correct manganese deficiency problems, and tells us that manganese is what is needed to ensure regular pecan crops with filled hulls.

Moving on to human nutrition, Elson Haas tells us that manganese is an essential part of the superoxide dismutase enzyme found in the mitochondria, the energy factories in the cells.  Manganese also activates the enzymes necessary for the body to use biotin, thiamine (B 1 ), vitamin C, and choline. (Staying Healthy with Nutrition p207).  Sally Fallon writes that manganese is "..needed for healthy nerves, a healthy immune system and blood sugar regulation....also plays a part in the formation of mother's milk and in the growth of healthy bones.  Deficiency may lead to trembling hands, seizures, and lack of coordination.  Excessive milk consumption may cause manganese deficiency as calcium can interfere with manganese absorption...phosphorus antagonizes manganese as well. (Nourishing Traditions p44).

Manganese can also be quite toxic.  It has been (likely still is) used as a flux or anti-oxidant coating on arc-welding rods, and some long-time welders have ended up with chronic and acute symptoms much like those listed above for manganese deficiency: trembling hands and other indications that appear identical to Parkinson's disease.

Manganese, we see,as well as being necessary, can be toxic, especially in diets or soils that are deficient in copper, zinc, and perhaps iron. The paragraph below was already posted above under copper and zinc, but bears repeating:

A brilliant British researcher, the late Mark Purdey, in his groundbreaking work with mad cow disease and chronic wasting disease, found in a worldwide survey that both mad cow and CWD were strongly associated with soils that had very low levels of zinc and copper, combined with high levels of manganese and sometimes high levels of strontium and silver.  In those conditions copper in the melanin granules, which are transmitters of outside information to the brain, may be replaced by manganese with disastrous results. In other words, neither mad cow disease nor chronic wasting disease are caused by infectious microbes, but are the result of a mineral imbalance. For more info on Mark Purdey's important work see his website carries Manganese in the form of Manganese sulfate, a purified soil amendment containing 32% Manganese and 19% Sulfur.  It is water soluble and is easily used for soil applications, fertilizer mixes, or foliar feeding.


Boron is one of the rarest elements, and one of the most mysterious.  It is absolutely essential for calcium metabolism, but no one seems to know its method of action.  An often heard phrase in the eco-agriculture field is "Calcium is the truck, but boron is the driver".  This refers to the concept that calcium is the transporter of  nutrients into and out of the cells, but it can't do its job unless boron is present. 

There are apparently only two commercially viable boron deposits in the world, one in Turkey and one in the Mojave desert of Southern California.  Boron is easily leached out of soils, so higher rainfall areas are often deficient.  In front of me is a map of the USA showing boron deficiency areas.  Essentially it shows everything east of the Mississippi River as boron deficient, as well as the Pacific NW as far south as the San Francisco Bay and as far east as central Montana.

Here's Charles Walters on boron: "Plants must have boron, again in the trace range.  Texts quote 2 to 75 parts per million as being essential, but note that plants vary in their required amounts according to species.  Boron is quite lethal to seeds when used in the salt form." ( Eco-Farm p136).  2 to 75 parts per million is a huge range.  At we would be very concerned to see available boron above 5ppm.  Our general rule is 1 part of boron to 1000 parts calcium. 

More on boron from Walters' Eco-Farm :  "Boron is required so that calcium can perform its metabolic chore.  It is essential in several other metabolic prevents such abnormalities as cracked stem in celery, internal cork in apples, black heart in beets and turnips, yellowing of alfalfa leaves.  When boron deficiency is a problem, death of the terminal bud is a common symptom.  Lateral buds continue to produce side shoots, but terminal buds on these side shoots fade away.  Rebranching may occur, but the multi-branched plant will take on the appearance of a rosette.
In cauliflower, heads fail to mature properly and remain small.  Reddish-brown areas become evident.  Terminal buds take on a light green color.....root crops are affected by brown heart, dark spots, or by splintering and cracking at the middle in....spuds [potatoes], sweet potatoes, radishes, carrots.
Boron is required for translocation of sugar, and this means boron deficiency can be spotted as a sugar deficiency.  Important as it is, a 100 bushel crop of corn requires only 4 ounces of boron.......a ton of alfalfa requires only a single ounce...boron regulates flowering and fruiting, cell division, salt absorption, hormone movement and pollen germination, carbohydrate metabolism, water use, and nitrogen assimilation.
In most soils boron is [found] as highly insoluble tourmaline, the supply being somewhere between 20 and 200 pounds per acre.  It takes life in the soil to draw on this bank account, and the Creator has supplied this life in the form of microorganism species which simply have to have boron to live.  By using the nutrient themselves and then contributing their bodies to the soil's fertility load, microorganisms change boron into an organic form.
When dry weather hits, microorganisms in soil without tilth and structure go dormant.  This means the boron supply is cut off.  Generally speaking there is more boron in the subsoil...and roots...dig deeper...for both moisture and for this very essential nutrient.
Too much boron will...restrict growth, cause plants to exhibit that sickly pale green color sometimes mistaken for nitrogen deficiency, preside over root deterioration and poor yield.  In short, either a shortage or marked imbalance of boron will set up a plant for insect and fungal attack."

Important stuff, boron.  It also has several more esoteric uses and connections, such as remediation of radiation poisoning.  According to another Charles Walters book, Minerals for the Genetic Code (based on the work of Dr. Richard Olree), boron controls all the +3 charges in the human body, and it is easily displaced by aluminum, losing three boron molecules to every one aluminum molecule.  Furthermore "Boron has the ability to absorb radiation and release it without changing the neutron.  The heart is the most active part of the body for which reason boron defends the heart.  The story has been told that Soviet truck drivers were offered bonuses to deliver boron to the Chernobyl site, this with the knowledge that their trip would be fatal, but families would be paid.  None realized that, fortified with boron [themselves], they could have made their decision with impunity. Boron stopped the "China Syndrome" from occurring in Russia." [ed. note: as is often the case, Walters is being a bit obscure here.  He appears to be stating that large quantities of boron were dumped on the nuclear pile at Chernobyl to stop the out-of-control nuclear reaction, and that if the truck drivers had swallowed some of that boron they would have been protected from radiation exposure.]

Continuing the quote on boron from Minerals for the Genetic Code : "Boron is known as the calcium helper and for the metabolism of calcium, magnesium and phosphorus.  Boron improves retention of both calcium and magnesium and elevates circulation of serum concentrations of testosterone.
Boron works in the body toward brain function, activates vitamin D, promotes electrical brain activity, enhances memory, and promotes alertness.  Signs of possible deficiency include ADD/ADHD, osteoporosis, arthritis, fatigue, decreased motor function, decreased short-term memory, decreased brain function, and increased loss of calcium and magnesium in the urine."

As if all that wasn't enough, boron in the form of boric acid is our safest and most effective ant control, and is used in many areas to treat wood in ground contact from ant and termite damage, as well as being used to fire-proof cellulose insulation and as a flux for soldering and brazing metal.  20 Mule Team Borax, available in the laundry soap section of most grocery stores, is a pure and natural mined product containing about 10% boron.  It is quite suitable for garden use in small quantities. 7 ounces of 20 Mule Team Borax per 1000 square feet equals approximately 1 part per million of boron.  Take it easy.  As noted above, a boron deficiency can be induced simply by dry soil.  Don't add boron without a soil test that indicates a need for it.  1-2 ppm per year is maximum. carries the Solubor brand of agricultural boron, which is standardized to 20% Boron.  It is water soluble and is easily used for soil applications, fertilizer mixes, or foliar feeding.

References Cited and/or Used for the above:
(In No Particular Order)

Eco-Farm  by Charles Walters and C. J. Fenzau  Acres USA 1996
Soil Chemistry 2nd Edition   by Bohn, McNeal, O'Connor  Wiley-Interscience 1985
Science in Agriculture   by Arden Andersen  Acres USA 2000
Mainline Farming for Century 21   by Skow and Walters Acres USA 1995
Staying Healthy with Nutrition
  by Elson Haas  Celestial Arts 1992
Nutrition and Physical Degeneration
  by Weston A. Price  Price-Pottenger Nutrition Foundation 1939/2004
Biological Farmer, the
  by Gary F. Zimmer  Acres USA 2000
Soil Fertility
  by Foth and Ellis  John Wiley and Sons 1988
Nutrition Rules
  by Graeme Sait  Soil Therapy Pty Ltd  2003
Chemistry Made Simple
  by Hess (rev. by Thomas)  Doubleday 1984
Minerals for the Genetic Code
  by Charles Walters with Dr. Richard Olree  Acres USA 2006
Nourishing Traditions
  by Sally Fallon with Mary Enig  New Trends 2001
Random House Dictionary of the English Language
2nd Edition Unabridged    Flexner and Hauck ed.  Random House 1987


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