Never Mind Your P’s &K’s, Mind Your S’s: S – Se – Si

By Philip A. Wheeler, Ph.D.

Most conventional farmers concern themselves with N-P-K but don’t realize the phosphate (P) on their farm is not very available to the growing plant and, except in obvious shortages, potassium (K) is usually more than adequate. Almost all of the soil tests that come through our lab from around the world are very short of Boron and other common trace minerals.  But, for those of you who have hopefully done some biological activation and CEC balancing, including the addition of  Boron, Copper, Iron, Manganese and Zinc particularly Cobalt and Molybdenum where needed, let’s try to progress in our ability to maximize soil and plant functioning by learning about the S’s.

For discussion of the three elements, Sulfur, Selenium, and Silicon, let’s take a unique approach.  We will examine each according to: its ancient history, i.e. what form was it is in pre-life times on earth and how did it come to be a part of plants/crops; what is its current form and purpose in plants/animals or humans; and how did Rudolph Steiner, the father of Biodynamics view them. Steiner was described as a mystic or clairvoyant, and literally saw things from a deeper, multi layered, physical and spiritual perspective, rather than a purely physical one, as you and I perceive matter.  In fact, throughout his childhood, teenage years and into young adulthood, he was unable to perceive of the physical alone as you and I would perceive it and always saw/experienced other layers of matter when looking at anything.  It will be interesting to see how his explanations of the 1920’s are confirmed by the science of the 1990’s and right up to today.

This approach is taken so that I may learn more about the Anthroposophical basis for Biodynamics and how it works.  Since my approach to agriculture is progressing in the direction of quantum biodynamics or energy manipulation, I need to be able to express the concepts in writing and in speech.  You are welcome to come along for the ride or ignore the parts about Steiner if you are not ready to expand your paradigm walls that far.  There is really nothing that mysterious about it.  Steiner used methods of capturing energy patterns (frequencies) coming from outside the earth that seem rather unusual at the time and still appear that way today.  Capturing and dispersing the energies required a great deal of time and energy (perseverance). However, today, we can record the frequencies of well made preps as geometric patterns using the Malcolm Rae technology and then achieve the desired results by broadcasting the frequencies correctly to fields and crops. A large number of hectares can now be covered with minimal labor, time and cost. (Readers are referred to Hugh Lovel’s book, A Biodynamic Farm, published by Acres USA.)

SULFUR [S]: Hydrogen sulfide gas [that rotten egg smelly stuff from high school chemistry] was the form of sulfur in the atmosphere of prehistoric times.  It also was attracted to metals like Iron in its solid or molten form. These forms were able to pass through the early living membranes and react with carbon in the earliest types of living things.  This established sulfur’s future use in protein formation of higher organisms.  As time progressed, much of the sulfur was deposited as pure elemental sulfur as found in various parts of the world.  However, much of the worlds sulfur now occurs in the form usable by plants, sulfate sulfur or SO4=such as in gypsum and potassium sulfate.  This conversion took place under the activity of thiosulfate bacteria, which used the newly formed oxygen atmosphere to oxidize the elemental sulfur. What seems as a strange twist of nature, this sulfate form of sulfur can not cross membranes easily and does not react directly with carbon.

In today’s crops, the sulfur acts as a major source of oxidation-reduction reactions, which means sulfur is at the center of a lot of energy producing reactions like the core of nuclear reactor.  Remember, growth and functioning of plants is all about energy, not about fertilizer.  Besides its energy reactions, it and iron are a major part of amino acid and protein production.  Sulfur is a physical part of the amino acids; cystine, cysteine, methionine.  It is also a part of the vitamins biotin, thiamine and co-enzyme A.  In addition to its function in other enzymes, it is involved in the physical structure as a part of lignin.

When a plant is short of sulfur, it can show chlorosis of lower leaves.  A more subtle, but very yield reducing symptom is the accumulation of sugar, starches and nitrates in the plant.  I have seen apple trees with a brix of 22 in the leaves at 9:00 AM and knew that it had not translocated yesterday’s production of sugar into the roots.

Soil test levels are supposed to be a minimum of 25 ppm or 50 lbs. of elemental S.  I consider that too low in most situations, but especially those involving forage crops.  When our factories in the US were spewing sulfur compounds, shortages weren’t a problem in many downwind croplands.  When nylon industry derived ammonium sulfate hit the market in Michigan in the mid 70’s, there was a hew and cry from Michigan State Univ.  about how Mich. soils didn’t need any sulfur.  Of course, when the product was applied, the benefits were obvious.  I have been recommending ammonium sulfate ever since, usually at 100-200 lbs./A in the fall each year on most all field and horticulture crops.  It checks out well radionically on most soils.  Some of the benefits of sulfur include reducing soil magnesium levels, increased water penetration, lowering of soil pH to increase nutrient availability, major improvement of forage quality, and increased heat tolerance of crops.


For those who are not allowed to use ammonium sulfate because its byproduct of manufacturing nature, other forms of sulfur are available that qualify as organic.  (Note that in Au., most of your ammonium sulfate is from the steel industry and it may have more contaminants than Nylon derived material)   Gypsum [calcium sulfate] is good for above pH 7 soils, but isn’t good for lower pH ranges unless accompanied by high calcium lime.  Elemental sulfur qualifies, but requires valuable soil oxygen and time to become available.  Sulfate of potash [0-0-50] is available in Australia, but it is usually more expensive than muriate of potash, and many local farm stores don’t stock it.  Laingebeinite or Sul-Po-Mag is a natural mineral and a source of sulfate sulfur.  However, the magnesium content may make it undesirable on many Au. soils.

CSI finds many soils with a high CEC content of magnesium, but low availability.  Using a few [5-40] lbs. of Epsom salts [magnesium sulfate] will usually act as an activator.  The small amount of magnesium added is not going to be a structure problem in high magnesium soils, but the active sulfur and magnesium may be just enough to stimulate other processes.  You can also foliar feed Epsom salts to correct plant constipation of nitrates or sugars.  Nitrate constipation is expressed by excessive early blossom or fruit drop.  The magnesium will counteract the nitrates and the sulfate sulfur will relieve the constipation, as it is a symptom of low sulfur.

During the original agricultural lectures by Dr. Steiner, he placed sulfur on a par with the other components of protein; carbon, hydrogen, oxygen and nitrogen.  He mentioned Langebeinite, (Sol-Po-Mag), as a source of sulfur.  From an anthroposophical viewpoint, he perceived sulfur as moving the etheric [a less dense physical form] body throughout the dense physical body of the plant that we perceive.  If a plant is short of sulfur, its etheric body form may not fill out the space of the physical form.  This leads to an imbalance of forces as well as an inability to gather/use the cosmic forces that regulate all plant life.  The result is less than optimum plant health with resulting disease, insect, etc. and a less than nutritious feed for animals and humans.

Steiner’s “remedy” for sulfur needs was to put yarrow flowers into a stag bladder and hang it in the summer sun and then bury it in the winter earth to capture the appropriate energies.  What he was trying to accomplish from a plant physiology standpoint, was to have the sulfur be able to carry/bring the other nutrients involved in protein to all parts of the plant.  A remedy made by Pfeiffer in the US in later years contained over 900 million acitinomycetes and bacillus type bacteria that are essential for N fixation.  The original ingredients contained only 300 aerobic bacteria per gram.  Steiner was also trying to capture the formative [making the unique shape of the plant species] forces associated with the planet Venus.  He used the stag bladder to take advantage of the stag’s ability to gather energy through its very sensitive antlers/antennas.  This is called remedy or preparation 502.

SELENIUM [Se]: Selenium began its history mainly in the form of hydrogen seleninide gas like sulfur.  Because it was a better transfer agent for electrons than sulfur, it was incorporated into the first living systems more easily that sulfur.  In fact, it is the only higher molecular weight, non-metal to be associated with an amino acid.  As oxygen became available in the atmosphere, aerobic organisms incorporated it as SeO2 or SeO4=.  Just as with sulfur, it does not readily cross membranes or react directly with carbon.

What selenium has become, in animals and humans, is a remover of organic peroxides, very active compounds that are formed naturally in the body.  These peroxides can become corrosive to the body and need to be controlled.  The immune system usually suffers when selenium is not present in adequate amounts.  Lack of Se in humans results in Kesham Disease and Kashin’s Beck disease, neither of which is very common.  However in livestock, deficiencies are more common.  In the late 50’s, White Muscle Disease [Nutritional Muscular Deficiency] was identified as a selenium deficiency.  The popular name came from the presence of calcium deposits in the muscle tissue.

To correct the selenium deficiencies, vitamin E was found to be synergistic with Se, so the popular Bo-Se/Mu-Se injectible with E and Se came on the market for livestock use.  If an animal is on pasture, the additional E is probably not needed.  Selenium feed and water supplements are also available.  The logical way would be to supplement would be to add selenium to soil to provide bio-active Se from feedstuffs.  However, there is great fear of excess Se in some parts of the US, which can be a problem.  Blind Staggers of cattle or chronic alkali disease was identified in the 1930’s as an excess of selenium.

A college level plant physiology textbook of 1983 makes no reference to selenium as a plant nutrient.  Steiner’s original lectures make no reference either.  Yet there is a lot of data from NZ, Au. and the US showing that supplementation of Se can increase milk and protein production, reduced retained placentas, increase sheep growth and wool production, and solve a lot of reproductive and immune system problems.

Some western parts of the US do have toxic levels of selenium in soils that can be expressed in forages.  Most of the East, South and Mid-West US, as well as Au. and NZ, are deficient.  There are few processed fertilizers that contain Se in the market place. Containers of common selenium salts are usually marked with toxicity labels, so handling/mixing can be a problem. Graziers should be aware of Se levels in all forages, including weeds and herbs, that their livestock have access to.  Blood levels should also be monitored for maximum health and production.

The author is unaware of any good mineral deposit in Australia containing significant selenium and other essential micro or macronutrients that would be suitable for agronomic application.  In the current marketplace, garlic, an accumulator of selenium, appears to offer a reasonable source.  Garlic is processed into juice that makes verifiable claims of increasing the immunity of plants and thereby repulsing harmful insects.  It is the sulfur and selenium compounds that produce this effect.  For livestock, the juice could be introduced into a water supply or placed on feedstuffs in a very diluted fashion.  However, carry through to milk could be a problem.  The better way would be to use the garlic juice as part of a nutritional foliar spray.  Garlic juice is highly systemic and will translocate itself and accompanying materials throughout the plant, regardless of type of materials or type of plant.  The garlic odor dissipates rapidly [to humans] and has no beneficial or detrimental effects.

SILICON (Si): Although classed as a non-mineral, Silicon is very similar in size and charge to its mineral neighbors in the periodic table of elements like sodium (Na), magnesium (Mg), aluminum (Al) and calcium (Ca).  As a result, it is found in the physical structures of most soils.  These compounds can be string like, plane or plate like and three dimensional arrangements of sand, silt and clay.

Silicon was first incorporated into some of the earliest living creatures, diatoms, whose silica shells have survived to this day.  We mine these deposits for DE or diatomacious earth, which is used as a wormer and external duster for livestock.  We also use it for kitty litter and soaking up spills.  In spite of silica’s pervasive presence through the world’s sands and soils, little mention of it was made in historical agriculture.  The 1983 plant physiology book suggests that it may be essential for rice and millet.  A 1999 conference of silica in crops still did not class it as necessary, but showed it as beneficial to rice, wheat, barley, cucumber and tomato.

Silicon is taken up by plants in the soluble form of silicic acid.  It becomes polymerized as a silica gel on the surface of leaves and stems to form a protective barrier.  Affects of increasing the uptake by plants include; suppression of powdery mildew and stimulation of most other plant defense mechanisms against diseases.  Although seemingly in inexhaustible supply in soils of all types, intense cultivation can result in soil depletion of available Si.  The rice and sugar cane fields of Florida, and Queensland and many other countries have responded to added silica.  While I was in Queensland a year ago, research reports indicated an over 50% increase in sugar production with the application of calcium silicate.

Calcium silicate slag [CaSiO3] appears to be one of the few forms that offer any response.  It can not be registered as organic, again because it is a byproduct of industry.  [The author finds this situation as rather sad and non-scientific and suggests the true measure of acceptability ought be based on cleanliness, bio-enhancement properties and contribution to yield/nutrition/ health rather than origin. Should we fill up our landfills [waste] materials that could grow healthy food for animals and humans because they are a byproduct of our industrial society?]

Much to my surprise and pleasure, one of the research reports of the 1999 silica conference was a report on silica in Biodynamic agriculture by a presenter from the Univ. of San Paulo, Brazil.  BD Preparation 501 is pulverized quartz (silica) in a dilute water solution.  The prep is designed to affect light incorporation into plants.  Research by Abele in 1987 showed higher yields in sugarbeets, and cereals grown under reduced light and treated with prep 501.  This confirmed earlier research by Kolisko in 1939 on 501.  Silica is important in the morphological and structural development of plants.  It also leads to greater insect and fungal resistance.

As you can see, minding your S’s can lead to more optimal soil, plant and livestock response as well as production of more optimum nutrition of foodstuffs. Shouldn’t our goal, as farmers/graziers, be to produce the maximum nutrition/energy possible in our products while being environmentally friendly/sustainable?