Considera

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Science of biodynamics: 1 Ground Rules

By Tom Mansell, Science Editor

Back when I was first getting into wine, I was shopping at Red Feet Wine Market, an Ithaca boutique wine shop. I noticed that some of their shelftalkers had little stickers (seen above) with the letters "O", "S"or "B". Having lived in Ithaca for a bit, I soon gathered that "S" stood for "sustainable" and "O" stood for organic.

I had no idea what "B" stood for.

"Biodynamic," owner Dewi Rainey informed me. "It's like organic plus."

Intriguing.

She went on to explain that in addition to being 100% organic, grapes are farmed according to an astrological calendar and how racking and other winemaking processes were done according to phases of the moon.

Okay…

Years later, this conversation has stuck with me. Phases of the moon? Astrological signs? Do people really believe this stuff?

It turns out that people do. Lots of them. Even the hallowed Domaine de la Romanée-Conti has vineyards given over to biodynamic farming. Many in the wine community are enamored by biodynamic wines. The notion of a vineyard in balance with nature appeals to people.

Since the first wines were made, the consumption of wine has been linked to some kind of spiritual experience (to Catholics, during the Mass, wine is transubstantiated into the Blood of Christ!). Therefore, it's easy to see why the spiritual language that describes wine is ubiquitious (e.g., "the soul of a great wine", etc.) and why wine grown using spiritual or cosmic forces may seem appealing.

Not everyone is crazy about biodynamics, though.

Stuart Smith, winegrower and owner of Smith-Madrone Vineyards in the Napa Valley, recently started a blog called, flatly, "Biodynamics is a Hoax." In it, he provides critical readings of Steiner's lectures on Agriculture, in addition to pointed critiques of biodynamic farming practices in general. It's a highly recommended read if you are in to this sort of thing.


Organic Viticulture and Labeling

I'm not going to go into all the details on this, since there are plenty of resources out there on organic wines, but here is a brief synopsis of labeling standards for organic wine products. All claims of "organic" must be certified. The certifier in New York is NOFA-NY.

100% Organic: All organic ingredients, no added sulfites
Organic: at least 95% Organic ingredients, no added sulfites
Made from Organically Grown Grapes: at least 70% organic ingredients, sulfites allowed
Biodynamic: Certified by Demeter USA or other biodynamic certification body

Science of biodynamics: 2 Moonstones OR Gravitas Vos Liberabit

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A key tenet of biodynamics is the influence of celestial bodies (e.g., the sun, moon, and planets) on agriculture. While no one will deny the influence of the sun, it's not clear exactly what the moon might be doing to affect grapegrowing and winemaking.

Take the case of Aleš Kristančič of Movia in Slovenia. Thanks to glowing reviews and a high-profile section of Sergio Esposito's book Passon On the Vine, Movia has gained cult status for wine consumers. Kristančič is a very popular speaker around the world and is consulted often for his views on biodynamic winemaking. He makes a wine called "Lunar", farmed with biodynamic methods and bottled on the full moon. His explanation:

Flying stones. The "minerals" in the wine, which are somehow visible under a microscope, are lifted from the sediment by the gravitational force of the moon. It's not uncommon to hear biodynamic winemakers reference lunar cycles when deciding when to rack or bottle wine.

The Nature of Gravity

I think it might be prudent here to clear up some misconceptions about gravity. The force of gravity causes any two objects that have mass to accelerate towards each other. While its presence on Earth is obvious, gravity is actually the weakest of the fundamental forces, about 10-37 times weaker than the electromagnetic force, for example. It also gets weaker with the square of the distance (i.e., objects twice as far away will exert four times less gravitational force on one another). The earth is so massive, though, that when it attracts your face to the pavement, it still hurts like heck.

As I mentioned, everything with mass has gravity. The nearest massive object with enough mass to have non-negligible gravity is, of course, the Moon. The Moon is approximately 1/80th the mass of Earth (which is still pretty massive), but it is also about 220,000 miles away from us. However, the effect of the Moon's gravity is still evident in the rising and falling of ocean tides.

Fit to be tide?

It's a common belief that human behavior is affected by the moon.
Proponents of such a theory would argue that the moon's effect on tides
is due to an affinity for water and that humans are about 60% water, so
there must be an effect. However, despite the repeated anecdotal
assertions of emergency room personnel and police, incidences
of trauma and traffic accidents, there is no convincing evidence that any such events correlate with lunar cycles.

Gravitationally speaking, there's really no difference between the new moon and the full moon. In both cases, the sun and moon are aligned, contributing the largest total gravitational pull (even though the Sun's is about 50% of the Moon's). For all intents and purposes, the gravitational effect of the moon on the Earth is identical on the new moon and on the full moon.

Tidal changes in the ocean are observed (1) because the ocean is enormous and (2) because solid material, while affected by the gravitational force in the same way, does not get pulled around in a significant way. Indeed, the Earth's crust is affected by the Moon's gravitational pull, just not enough to be noticeable.

Let's put some numbers behind this. The acceleration due to the gravity of the moon (at the perigee, when the moon is closest to the earth) is approximately 1.34 x 10-7 times g the Earth's gravitational acceleration. The force generated by the moon that opposes the Earth's gravity is one ten-millionth the force of the gravity of Earth.

To put this into perspective, the gravitational acceleration in New York City vs. Los Angeles differs by about 0.06%, which is about 6,000 times more than the tidal difference in gravity.

Gravity affects every object with mass, not just water. And it certainly doesn't discriminate between "minerals" and other sediment. Will your wine settle differently in LA than in NY? Yes, but the moon will have very little to do with it.

As for racking and bottling, while there may be a slightly different gravitational effect on a quarter moon (neap tide) than a full or new moon (spring tide), is it more likely that this infinitesimal effect will change the sedimentation profile of the wine, or that it will be affected by flow or shape of the tank or bumping of the lees with the racking wand or seismic disturbances or any other more terrestrial factors?

To rephrase an old adage, wines housed in a glass don't throw stones.

Further reading

M Sawicki, "Myths about Gravity and Tides," originally published in The Physics Teacher, 1999.

SO Lilienfeld and H Arkowitz, "Lunacy and the Full Moon", Scientific American, 2009

DA Thompson, SL Adams, "The full moon and ED patient volumes: Unearthing a myth", The American Journal of Emergency Medicine, 1996.

The Science of Biodynamics, Part 3: Organic Viticulture in Long Island

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I think we can all agree that sustainability in viticulture is important. I mentioned in my first post that our discussion about the science of biodynamics cannot leave out organic viticulture. I asked Alice Wise, viticulturist at the Long Island Horticultural Research and Extension Center (LIHREC) about some of the nuts and bolts of organic viticulture in Long Island.


NYCR: What are the primary challenges of organic viticulture in regions like Long Island?

AW: The goal is economically viable yields of high quality fruit – no matter what the management philosophy. Beyond that, growing season rainfall and morning dew favor fungal diseases such as black rot, phomopsis and downy mildew. The only National Organic Program (NOP)-allowed fungicide that provides significant control of downy mildew is copper, but no NOP-allowed material provides very good of control of black rot and phomopsis. Powdery mildew, on the other hand, is quite readily controlled by sulfur and mineral oil, both NOP-allowed.

NYCR: What are some ways to maintain nitrogen content in organic soil?

AW: Leguminous cover crops, though they must be tilled in for maximum benefit. There are organic nitrogen fertilizers such as peanut meal and others. They tend to be pretty expensive. For sandy soils, compost and/or composted manure helps with nutrition as well as nutrient retention. Realize that grapevines, at least vinifera on Long Island, do not need a lot of nitrogen so to me this is not one of the pivotal points of organic practice.

NYCR: How do organic treatments for downy, powdery, eutypa, botrytis, etc. differ from conventional treatments?

AW: The term organic is legally defined as it pertains to pesticide use. The NOP should have good information. Or go to http://www.epa.gov/pesticides/food/organics.htm.
The effective materials allowed for use by the NOP are all used by non-organic growers to one degree or another, particularly sulfur and mineral oil.

The exception might be copper. Some growers won’t use copper, or limit its use, because it has a 2,600 day soil half-life and permanently builds up in the soil to toxic levels with continuous use. This has not been an issue here but is an issue in more established winegrowing regions.

NYCR: Are conventional herbicides/pesticides really that bad for the soil?

AW: Anything that is done to soil potentially alters the structure and the biology – herbicides, cultivation, cover crops, they all have impacts. Regarding the impact of herbicides, I have read/heard discussions with arguments on both sides. One measure of potential impact (or lack thereof) of herbicides on the soil is their soil half-life*. A relatively low half-life means soil microorganisms consume the material and transform it to CO2 and H2O pretty quickly. Many modern herbicides have low leaching potential and short half-lives and are not considered “bad” for the soil. My opinion is that there is no perfect method to manage vegetation under the trellis, each option has advantages and disadvantages.

*Note: A word about half-life: Most processes are best assumed to occur in a first-order way. That is, things will undergo exponential decay. The term "half-life" is a function of the time constant of this decay. More simply, half-life is the amount of time it will take for half of the material of interest to degrade. After two half-lives, 25% (1/4) of the original material will remain. After 3, 12.5% (1/8), and so on. -tjm

NYCR: Copper is allowed in organic viticulture but – as you said – a common complaint is that it builds up in the soil. Are there any more eco-friendly copper alternatives at this time? Is copper buildup in soil as bad as some would claim?

AW: Copper use is limited and/or banned in some regions of Europe due to accumulation in the soil. Any soil copper level over 100 mg/kg is considered toxic and levels in French, Italian, Australian and New Zealand vineyard soils are not uncommonly found at 200, 300, 400+ mg/kg where copper has been used for decades. High soil levels of copper inhibit plant growth, impair soil microbial life, and drive out earthworms*. ‘Eco-friendly’ is not a legally defined term so I can’t comment on that. There are hydrocarbon-based, reduced risk options (for reduced risk definition, see http://www.epa.gov/pesticides/health/reducing.htm) for control of downy mildew but to my knowledge the only effective organic option is copper. Remember that both the active ingredient and inert ingredients must be approved by the NOP. Consequently, not all formulations of copper are organically approved. This holds true for other materials as well.

*Note: Earthworms are important to soils for many reasons, including their burrowing behavior, which increases soil drainage, and repeated turnover of the upper soil layer. Exposure to copper in earthworms at low levels can have detrimental effects on burrowing activity and at higher levels can be toxic to worms. Pictured right: Copper sulfate powder. -tjm




NYCR: You are running a trial on organic viticulture at LIHREC. Can you share any preliminary results?

AW: We are running the trial on chardonnay, probably the most difficult candidate for organic management. Overall, we have had difficulty with black rot, phomopsis and downy mildew in organic plots. Cluster rots have been problematic as well.

However, we have harvested fruit every year, though yields have been reduced. Vine size has suffered as well and we’re not quite sure why. Our current thinking is that it is due to cumulative stress rather than any one factor. We ended up using a conventional nitrogen fertilizer this year just because vine size was declining so much. It definitely helped.

NYCR: I assume leaf removal is essential for disease control in an organic regimen. What are your thoughts on the Long Island cultural practice of 100% leaf removal from the fruiting zone vis-à-vis disease control and fruit development?

AW: The issue of timing and severity of leaf removal is not specifically related to organic viticulture. Leaf removal in the cluster zone is done for both quality and pest management reasons for VSP trained vines. The more extreme version of leaf removal is done, as I am told by vineyard managers who do it, so that only one pass has to be made rather than repeated passes to maintain adequate air flow and light penetration. Some feel ‘leaf stripping’ of the cluster zone has quality benefits as well and I have seen some data to that effect. I have also seen fruit with sunburn – we did a version of leaf stripping this spring and ended up with a lot of sunburn on exposed clusters on the west side of the trellis. Whether the fruit is riper, we’ll find out at harvest.

NYCR: How does the cost of organic farming compare to conventional methods?

AW: As organic vinifera is not common in the eastern U.S., a standard set of practices has not really been recognized. So much depends on which pesticides and fertilizers are used as costs vary considerably. Often organic management involves an increase in labor. However, there is just not any solid information on costs. The version of organic that we used in our trial was more expensive than conventional methods but we only evaluated spray materials. I would guess there might be data from the west coast where there are many organic vineyards. But it would not be completely relevant to Long Island as the viticulture is so different.

NYCR: Have you tested any of the biodynamic preparations (e.g., horn manure, horn silica, compost treated with yarrow, valerian, dandelion, etc.) in your vineyard? Why or why not? Did you discover anything?

AW: No, nor will you find any true replicated studies with these preparations. In science, we have to reduce potential variability in treatments as much as possible. To my knowledge, there are no legal standards for producing these materials, hence variability in product might account for treatment differences. Some may even fall into a legal gray area as well since any product applied for control of a pest must have EPA and NYSDEC approval.

Regardless, since biodynamics involves a degree of faith or mysticism or whatever you want to call it, this does not lend itself to rigorous scientific evaluation. It may be interesting, but it would be hard to do a valid scientific study. And as biodynamics is a systematic approach, it might not make sense anyway to evaluate individual components. There was a west coast study that looked at conventional vs. organic vs. biodynamic over several years. It is summarized in the ASEV journal. I think it was done in WA and CA.

Note: One of the studies referred to can be found here and here. We'll be addressing the results of these studies in a later post.

So it seems like downy mildew is a real bugbear. For those growers who want to avoid using copper, there is an alternative known as phosphites. Phosphites have been shown to be effective against downy mildew, but the fungus can develop resistance to this chemical.

My understanding is that phosphite compounds are moving towards organic certification.

This brings up an interesting question. As was discussed in the comments section of part 1 of this series, sulfur, copper, hydrogen peroxide and mineral oil are "okay" to use in certified organic viticulture, but they are synthetic chemicals. Phosphite salts seem to be in the same vein.

What differentiates a fungicide like Captan from Phosphites? Both are made in synthetic chemical processes. Both have relatively short half-lives in soil. Is it their overall toxicity? Captan can be toxic to freshwater fish but Fosetyl-Al, a commercial phosphite preparation, can also be toxic to mussels. Both have been evaluated by the EPA and "can be used without causing unreasonable adverse effects in people or the environment."

If "organic" includes synthetic products, then where do we draw the line on synthetic? Or should we?

Further Reading:

For more information about herbicides and pesticides, visit ExToxNet

Organic Agriculture Trials at LIHREC

H Eijsackers, et al., "The implications of copper fungicide usage in vineyards for earthworm activity and resulting sustainable soil quality", Ecotoxicology and Environmental Safety, 2005.

JR Reeve et al., "Soil and Winegrape Quality in Biodynamically and Organically Managed Vineyards" AJEV, 2005.

H Thao and T Yamakawa, "Phosphite (phosphorous acid): Fungicide, fertilizer or bio-stimulator?", Soil Science & Plant Nutrition, 2009.

For more info on downy mildew, see this post from Evan from about a year ago.

The Science of Biodynamics, Part 4: Hidden Alchemy in Compost

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"For there is a hidden alchemy in the organic process." – Rudolf Steiner, Agriculture

At the heart of biodynamic farming are the famous preparations. In this post and the next post, we'll look at the contents of the preparations and their proposed effects and mechanisms or lack thereof.

This week's post will focus on the preparations added to biodynamic compost.

Compost Preparations

Preparation Main Component Fermented in… Proposed function (Steiner) Proposed function (Josephine Porter Institute website)
502 Yarrow blossoms Bladder of a stag "Its homeopathic sulfur content, combined in a truly model way
with potash, not only works magnificently in the plant itself, but
enables the yarrow to ray out its influences to a greater distance and
through large masses." Permits plants to attract trace elements in extremely dilute quantities for their best nutrition.
503 Chamomile blossoms Cow intestines "…has sulphur in the precise proportions which are necessary to assimilate the potash…assimilates calcium in addition. Therewith, it assimilates that which can chiefly help to exclude from the plant those harmful effects of fructation, thus keeping the plant in healthy condition." Stabilizes nitrogen (N) within the compost & increases soil life so as to stimulate plant growth.
504 Stinging nettle shoot N/A "A jack of all-trades… It carries within it the element which incorporates the Spiritual and assimilates it everywhere, namely, sulphur….Moreover, the stinging nettle carries potassium and calcium in its currents and radiations, and in addition it has a kind of iron radiation." Stimulates soil health, providing plants with the individual nutrition components needed. "Enlivens" the earth (soil).
505 Oak bark Skull of a domestic animal "The calcium structure of the oak rind is absolutely ideal….[Calcium] restores order when the ether-body is working too strongly, that is, when the astral cannot gain access to the organic entity." Provides healing forces (or qualities) to combat harmful plant diseases.
506 Dandelion flowers Mesentery (gut lining) of a cow "t mediates the silicic acid finely, homeopathically distributed in the Cosmos, and that which is needed as silicic acid throughout the given district of the Earth. Truly this dandelion is a kind of messenger from heaven." Stimulates relation between Silica (Si) and Potassium (K) so that Silica can attract cosmic forces to the soil.
507 Valerian extract N/A "…stimulate [the compost] to behave in the right way in relation to what we call the 'phosphoric' substance." Stimulates compost so that phosphorus components will be properly used by the soil.
The preparations (that's 503 at right) are usually placed directly into the compost pile in small amounts, typically 5-10 grams or less for the solid mass, though they can sometimes be sprayed in the field in addition.

In his fifth lecture on agriculture, Steiner argues that the nitrogen content of biodynamic compost is improved by transmutation of elements such as potassium and calcium into nitrogen by organic processes.

"I know quite well, those who have studied academic agriculture from the modern point of view will say: "You have still not told us how to improve the nitrogen-content of the manure." On the contrary, I have been speaking of it all the time, namely, in speaking of yarrow, camomile [sic] and stinging nettle. For there is a hidden alchemy in the organic process. This hidden alchemy really transmutes the potash, for example, into nitrogen, provided only that the potash is working properly in the organic process. Nay more, it even transforms into nitrogen the limestone, the chalky nature, if it is working rightly."

This represents a misunderstanding of the nature of chemical elements, even by 1924 standards. The supposed phenomenon of biological transmutation, or the conversion of an element to a different element via a biological or organic process, quite simply violates the laws of physics.

It's important to note, though, that just because Steiner was a bit off in his explanation of the phenomena doesn't mean that these compost preparations have no effect at all. Many researchers have explored the effects of biodynamic agriculture, but until recently, these studies either compared conventional and biodynamic agriculture or lacked the statistical rigor required to make definitive conclusions. However, in the past decade or so, some intrepid researchers have taken a scientific approach to experimentation with the biodynamic preparations in an effort to gauge their efficacy and usefulness for modern farmers.

A review of peer-reviewed research into the effects of biodynamic preparations

One of the premier researchers in the compost field is Dr. Lynne Carpenter-Boggs, Biologically Intensive and Organic Agriculture (BIOAg) Specialist at the Washington State University Center for Sustaining Agriculture and Natural Resources (CSANR) and an affiliate Assistant Professor in the Department of Crop and Soil Sciences. She has been an author on several peer-reviewed papers comparing the effects of agriculture using biodynamic preparations to organic agriculture.

Washington Com-post

A 2000 study published in Biological Agriculture and Horticulture showed some differences in compost quality between
biodynamic and organic compost. The biodynamic compost had a
consistently higher temperature and 65% more nitrate (likely due to
aerobic nitrifying bacteria, not transmutation…) than the organic
compost. In addition, phospholipid fatty acid analysis gave different
results for biodynamic compost, suggesting that the microbial makeup differed slightly.

Also in 2000, the same authors published a study in the Soil Science Society of America Journal which sought to evaluate the differences in soil treated with organic or biodynamic compost. The authors also compared the results of composted soils to soils supplemented with mineral fertilizers. Over the many parameters measured, compost was shown to beneficial to soil quality, but no significant differences were found in any parameters between organic and biodynamic compost.

From the conclusions section:

"The soil biological parameters tested indicated many differences between soils that had received compost additions and those that had not. Both biodynamic and nonbiodynamic composts increased soil microbial biomass, respiration, dehydrogenase activity [an indicator of microbial activity], MinC [an indicator of available carbon], earthworm population and biomass, and qCO2 [microbe respiration]. No differences were found between soils fertilized with biodynamic vs. nonbiodynamic compost."

Does it translate to plants?

Wheat


In 2010, Dr. Jennifer Reeve, Assistant Professor of Organic and Sustainable Agriculture at Utah State University and a former student of Dr. Carpenter-Boggs, was the lead author on a study of biodynamic compost and its effect on wheat seedlings.

In this case, the compost contained grape pomace, which would be a readily available source of compost from wineries. The authors tracked compost parameters like the 2000 studies and found evidence of increased dehydrogenase activity, which indicated increased microbial activity in the biodynamic compost.

In addition, wheat seedlings were fertilized with the different composts. According to the paper, "In 2002, wheat growth with BD compost extract or BD compost extract plus fertilizer was always greater or the same as wheat growth with the control compost under the same conditions….Wheat growth in 2005 was similar
between BD and untreated compost showing that possible differences as a
result of BD treatment are not consistent year to year. Whether or not
any small differences as a result of BD compost preparations would
incur a practical benefit to the grower needs to be further
investigated." Seedlings treated with either compost extract had higher shoot height and biomass and root biomass, confirming the beneficial effect of compost in general.

Okay, fine for wheat, but this isn't the New York Wheat Report. What about grape vines?

One of the first peer-reviewed studies of biodynamic compost on grapes appeared in the prestigious American Journal of Enology and Viticulture in 2005. Dr. Reeve and Dr. Carpenter-Boggs were co-authors on this study. A three-year study of application of BD compost vs. organic compost (the only difference being the addition of preparations 502-507).

Biodynamically treated vines in this study also received field sprays (preparations 500 and 501). I'll go more into the effects of field sprays in next week's post.

According to the paper: "No consistent significant differences were found between the biodynamically treated and untreated plots for any of the physical, chemical, or biological parameters tested….Also, no differences were found in the more sensitive measures of microbial efficiency known as biological quotients: dehydrogenase activity per unit CO2 respiration, dehydrogenase activity per unit readily mineralizable carbon, and respiration per unit microbial biomass."

Analysis of the grape chemistry showed very little difference among the three harvests. One exception was 2003, slightly increased (though statistically significant) Brix levels (25.88 vs. 25.55) and approximately 2.5% and 5% increases in total phenolic compounds and anthocyanins, respectively. From the paper: "Based on the fruit composition data, there is little evidence the biodynamic preparations contribute to grape quality. The differences observed were small and of doubtful practical significance."

OK, so maybe there isn't any practical significance in grape chemistry. The wine is what's important!

The same wine grapes from the 2005 AJEV study were vinified and compared in a trained sensory panel. The first test was to see if the panel could tell any differences between wines made from organic and biodynamic grapes.

From the paper: "Triangle test results indicated no significant differences at p<0.05 [that is, 95% probability that the result is not by chance] between the 2001, 2002, 2003 and 2004 biodynamically and organically grown Merlot wines."

Those that were able to correctly identify differences found slightly higher perception of in "musty/earthy" aromas in some of the organic wines. The only wine that was showed a notable preference was the 2003 vintage, where subjects preferred the organic wine over the biodynamic (p<0.1).

This is the same vintage where biodynamic wines had slightly increased Brix, and phenolics, which may explain the result that in that the 2003 biodynamic wine was notably (again, p<0.1) higher in bitterness.

This is hardly a resounding endorsement for the quality of biodynamic wine over wine produced organically.

If there really is an effect, then how might it work?

The possibility of an altered microbial population in BD compost found in the 2000 and 2010 studies led the authors to consider
microbial inoculation (i.e., the addition of beneficial microorganisms
from the preparations) as a possible reason for the change in the
compost. However, given the small inoculum (approximately 1 mg of
preparations per kg of compost), this mechanism was considered to be
unlikely but could not be ruled out.

I asked Dr. Carpenter-Boggs if
further studies have been done to examine the microbial makeup of the
compost. Her response was that the small, subtle changes in
biodynamic compost aren't really enough to justify further exploration
of the microbial makeup, which would likely be painstaking and expensive.

According to Dr. Reeve, "any mechanistic hypotheses are pure speculation at this point."

However, she seems to favor an explanation involving molecules that are capable of influencing plant and/or bacterial growth in small quantities. These hormones, molecules such as cytokinins, certainly exist in nature, but proving this hypothesis would be equipment and labor intensive, requiring extensive chemical analysis.

Dr. Reeve admits "it's quite possible that these results are flukes," and she argues that there aren't enough practictioners of biodynamics out there to gain a statistically significant grasp on the benefits of biodynamics over organic farming.

Conclusions

Compost as fertilizer performs better in many soil health metrics (micronutrients, microbial populations, etc.) than conventional mineral/NPK fertilizer. However, the differences between biodynamic compost and compost managed without biodynamic preparations are few and relatively subtle.

Compost with biodynamic preparations may have slightly altered microbial populations, but when BD compost is applied to crops, it gives little advantage over organic compost. Grapes produced using biodynamic viticulture treatments showed very little practical difference, and wine made from those grapes showed no statistically significant differences to a large panel of subjects.

Rigorous research into the effects of the biodynamic compost treatments may have produced small blips on the radar, but these results have either been inconsequential overall or irreproducible.

Further research may elucidate possible mechanisms, if any. Meanwhile, one consistent result is the beneficial effect of compost on crops. So while composting may be beneficial, there's little evidence to support the use of biodynamic compost preparations.

Further Reading

R Steiner, Agriculture, 1974 translation.

L Carpenter-Boggs et al., "Organic and biodynamic management: effects on soil biology." Soil Sci Am J., 2000

L Carpenter-Boggs et al., "Effects of biodynamic preparations on compost development." Biological Agriculture and Horticulture, 2000

JR Reeve et al., "Influence of biodynamic preparations on compost development and resultant compost extracts on wheat seedling growth", Bioresource Technology, 2010

JR Reeve et al., "Soil and Winegrape Quality in Biodynamically and
Organically Managed Vineyards", AJEV, 2005

CF Ross et al., "Difference Testing of Merlot Produced from Biodynamically and Organically Grown Wine Grapes." Journal of Wine Research, 2009.

The Science of Biodynamics, Part 5: Field Spray Preparations: Stirring Controversy

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We now come to some of the most famous and well-known preparations in biodynamics, the field sprays. Cow manure or silica fermented in the ground in cow horns is practically the very symbol of biodynamics. These preparations are highly representative of the movement, but what, if anything, do they do?

Field spray preparations

Preparation Main Component Fermented in… Proposed function (Steiner) Proposed function (JPI)
500 Cow manure Horn of a cow "We preserve in the horn the forces it was accustomed to exert within the cow itself, namely the property of raying back whatever is life-giving and astral…. [T]he manure inside the horn is inwardly quickened with these forces, which thus gather up and attract from the surrounding earth all that is ethereal and life-giving." Stimulates root growth and humus formation. Stir one hour.
501 Finely ground quartz or feldspar Horn of a cow "It will prove most beneficial with vegetables and the like…. [Y]ou will soon see how the dung from the cow-horn drives from below upward, while the other draws from above." Stimulates and regulates leaf growth. Apply to foliage during the growing season. Stir one hour.
508
Horsetail (Equisetum) extract

N/A Assume now that the moon influence is too strong….Thus we see the forming of mildew, blight, rust, and similar diseases….This [horsetail tea] we dilute, and sprinkle it as liquid manure… wherever we want to combat rust or similar plant-diseases.
For preventing or controlling fungus diseases.

These preparations are diluted in water, "dynamized" (more on that later), and sprayed onto vines.

Dynamization

What is dynamization? From Steiner:

"You must, however, thoroughly combine the entire content of the horn with the water. That is to say, you must set to work and stir. Stir quickly, at the very edge of the pail, so that a crater is formed reaching very nearly to the bottom of the pail, and the entire contents are rapidly rotating. Then quickly reverse the direction, so that it now seethes round in the opposite direction. "Do this for an hour and you will get a thorough penetration. Think, how little work it involves! The burden of work will really not be very great. Moreover, I can well imagine that [...] the otherwise idle members of a farming household will take pleasure in stirring the manure in this way. Get the sons and daughters of the house to do it and it will no doubt be wonderfully done.

Nowadays, some farmers have lots of spray to make and stirring by hand for an hour, in spite of Steiner's assertion, can be tedious. Thus we have seen the development of flowforms. Flowforms are large structures containing basins with geometries that allow water to swirl in oppposing vortices as Steiner suggests (seen at the beginning of the video below).

video?

The theory behind this process is that it adds "energy" and oxygen to the water. What this "energy" is is ill-defined. From Nicolas Joly's book Wine from Sky to Earth: "Dynamization creates a profound intimacy between the solid and the subtle, between what one dynamizes and the water. The rhythm acts like an appeal." He then digresses into a discussion of artificial insemination of cows.

The addition of oxygen to the mixture, though, is real. Agitating the liquid will saturate it with oxygen, except this happens fairly quickly, not after an hour. The reason for this is that oxygen is not very soluble in water to begin with, only soluble at about 8 ppm, or 8 mg/L and it is even lower when the water is warmer. This low solubility is the reason we require the protein hemoglobin to transport oxygen in our blood, since the saturated level wouldn't be nearly enough to sustain our oxygen needs.

While it is possible that the fermented product could be consuming oxygen during this hour (fermenting wine, for example, would consume about 2 ppm of oxygen per minute), the small amounts of compost and/or silica added to the large amount of water make this unlikely. Therefore, it is probably safe to conclude that dynamization of a preparation of 100L will add approximately 800 mg of oxygen, about half the oxygen contained in one breath of air.

Spraying Science

While preparations 500 (horn manure) and 501 (horn silica) have been found to contain high levels of cytokinins (plant stimulatory hormones), research done by Dr. Jennifer Reeve (as mentioned previously) showed that "The biodynamic field sprays (500, 501 and barrel compost) were not shown to have any effect on soil quality." Thus, the mode of action, if any, of preparation 500 is likely similar to that of the compost preparations mentioned previously.

For more information about compost preparations, see the previous post in this series.

Silica and Sunlight

Steiner's proposed mechanism for the effectiveness of preparation 501 is the intimate connection of silica to cosmic forces. Recent rationalizations of silica's effect on leaves include postulating that the silica crystals (ground quartz) focus and/or refract sunlight like a "prism", causing more sunlight to contribute to photosynthesis.

The accompanying video has Mike Benziger of Benziger Vineyards giving his explanation of this phenomenon (around 1:18).

video?

This is rather unlikely for several reasons. First, the silica is white and thus reflective, so some sunlight that could have fallen on the leaves is reflected back. Second, prisms do not magnify light or shift colors. When light is refracted through a prism, it is broken into its constituent wavelengths, not redshifted significantly. Third, even if the silica did "bend the sunlight more towards infrared", the maximum absorbance of chlorophyll occurs in the purple-blue range of visible light, with a minor peak in the red-orange area.

Essentially, the hypothesis that quartz crystals intensify the sunlight that reaches leaves is likely bunk.

Silica and Fungus

An interesting thing about silicon is that while it is mostly inert (in sand, glass, quartz, etc.), it can be converted into bioactive forms and used by organisms. One obvious example of this is diatoms, whose silica skeletons form diatomaceous earth (kieselguhr). Silicon is also taken up by plants and incorporated into stems or, in some cases, segregated to large silicous masses inside the plant. This is the case with horsetail (Equisetum), the dry weight of which can be up to 70% silica.

Indeed, spraying plants with bioactive forms of silica has been shown to help protect them against fungal disease. Most of this research has been done with rice, but there exists studies where spraying with potassium silicate decreased incidence of powdery mildew on grapevines. In a 1996 study in the American Journal of Enology and Viticulture, Reynolds et al. concluded that applying potassium silicate did reduce incidence of powdery mildew, but not as well as the fungicide Kumulus S (sulfur).

It's unlikely that silica is directly toxic to microbes, so what could the mechanism of this silica effect be? We might speculate that the spraying of silica onto plants via horsetail tea and/or preparation 501 might invoke some sort of resistance in the plant. The hypothesized mechanism is due to what is known as systemic acquired resistance.

Essentially, since silicon naturally builds up at sites of plant injury and infection, it stimulates the production of the plant's natural defenses, antimicrobial compounds. Increased uptake of silica may trick the plant into thinking it is under attack, prompting the synthesis of these compounds so that when fungus does attack, the plant is at the ready.

It's possible, then that the silica, which enters a cow horn as inert quartz, could be converted by microorganisms into bioactive forms like silicates. In horsetail, much of the silica is already present in bioactive form. If this is true, preparations 501 and 508 could indeed be providing some measure of fungus control in the vineyard, but it probably has nothing to do with crystals refracting sunlight or dynamization imbuing these mixtures with cosmic forces.

Further reading

R Steiner, Agriculture

N Joly, Wine from Sky to Earth: Growing and Appreciating Biodynamic Wine

AG Reynolds et al., "Use of potassium silicate for the control of powdery mildew [Uncinula necator (Schwein) Burrill] in Vitis vinifera L. cultivar bacchus", AJEV, 1996.

Fauteux et al., "Silicon and plant disease resistance against pathogenic fungi", FEMS Microbiology Letters, 2005

The Science of Biodynamics, Part 6: Organic Vinifera in the Finger Lakes

http://newyorkcorkreport.com/blog/2010/ ... ger-lakes/

This series has provoked important conversations about biodynamics, organic growing, and sustainability. Organic grapegrowing should definitely be a part of this discussion, so just as I interviewed Alice Wise regarding organic viticulture in Long Island, the following is a profile of Richard Figiel and Silver Thread Vineyard in the Finger Lakes.

If you weren't looking for it specifically, you might not even know it was there. A small sign on Route 414, the Seneca Lake Wine Trail East, indicates that there is a Silver Thread Vineyard, but unlike many of the wineries on Seneca, it's not immediately off the main drag.

By the time you reach the bottom of a bumpy ride downhill on 3/4 mile of dirt road, you're convinced that you were in the wrong place — except you see grapevines. Just before harvest began back in September, I journeyed out to Silver Thread to talk organic viticulture.

The winery itself is set into the hillside of a deep slope on the shore of Seneca Lake. I entered to find owner, winemaker, vineyard manager, and pretty-much-everything-else manager Richard Figiel in the cellar taking Brix measurements on gewürztraminer juice. The cellar was much cooler than the outside, even on one of few milder days of early September. Figiel immediately explained that the winery being practically underground provides natural temperature control for his fermentations, though the small wood stove (the winery's only heat source) is there for colder winter days.

Silver Thread grows riesling, pinot noir, cabernet franc, chardonnay and gewürztraminer, producing 1,000-1,500 cases per year in what is essentially a one-man operation. Figiel has been growing grapes at this vineyard since the mid-1980s, and organic production was always part of his vision. Long before organic was a buzzword (when, according to him, the only people interested in organic were "hippies"), Figiel saw organic grapegrowing as "a responsible way to farm."

Organic in the Finger Lakes

The winery was certified organic in 1992, but a change in the buffer zone requirements (i.e., regulations for proximity to conventional vineyards) caused it to lose its certification in the late 1990s. Nowadays, it seems that NOP certification is not really the highest priority, though Figiel's commitment to responsible growing has not gone away with the certification paperwork.

Organic practices are still the baseline here, with only small deviations.

For example, not long after the period where the vineyard was completely organic, grape leafhoppers had become a problem. These insects feed on grape leaves and in high numbers can cause significant damage to vines. A treatment with a pyrethrum-based insecticide took care of the leafhopper infestation, and they haven't been back since.

The familiar, groomed herbicide strips of the average vineyard are completely absent from Silver Thread. In fact, parts of the vineyard are downright wild. Figiel uses no spot herbicides, and his main tool for weed control is the grape hoe.

Fighting fungus

One of the biggest challenges of organic viticulture is control of fungus, and the biggest problems in this region are powdery mildew, downy mildew and botrytis. Without the luxury of conventional fungicides, organic growers turn to interesting alternatives.

JMS Stylet Oil, which Figiel uses to control powdery mildew, is a highly refined mineral oil, a by-product of the petroleum industry. Its specific mode of fungicide action is not entirely understood, but a possible explanation is the creation of a physical barrier between fungal spores and the air, making it difficult for them to germinate. Other explanations include disruption of fungus membranes and the activation of natural plant defenses. Stylet oil can be effective against powdery mildew and botrytis, but is not effective against downy mildew.

Also part of Figiel's toolkit is Serenade, a fungicide whose active ingredient is a strain of Bacillus subtilis, a bacterium known to be agonistic to fungus. He also uses sulfur (of course) and copper hydroxide, though his soils have not shown a significant increase in copper over the years. "Ideally, in a year, I won't use it at all," Figiel says regarding copper. (See Part 3 of this series for information on copper fungicides and soil health.)

Finally, horsetail grows wild on the site, and Figiel makes his own horsetail tea to spray for fungus control. Horsetail extract is rich in bio-available silica, which, as previously discussed in this series, has been shown to have fungicidal properties. It is also known as biodynamic preparation 508.

Regarding other biodynamic practices, Figiel composts pomace and local sheep and goat manure, and does add some biodynamic preparations to the compost, though biodynamics per se doesn't seem to be too important to him. You won't find horn silica or manure, and you won't find him consulting an astrological calendar for harvest days.

In the Winery

When it comes to winemaking, Figiel likes to keep it simple. No chemical yeast nutrients such as DAP are added. Most of his reds begin with wild fermentations, which are then finished off by inoculation with commercial yeasts.

As mentioned, temperature control is accomplished by the cellar itself. Slight additions of SO2 (20-30 ppm based on pH) and fining with bentonite are common, as is sterile filtration at bottling, a regional standard. Figiel characterizes his practices as "simple, rustic winemaking." I agree.

Silver Thread strives to be a winery that makes quality wines with as little impact on the environment as possible. This is evident in all aspects of the winery from the gravity-fed water supply, the meager wood stove heating, the natural temperature control of the cellar, and the commitment to organic viticulture. Figiel even dreams of replacing his tractor with horses to reduce carbon dioxide emissions. Horses would also provide a ready source of manure for fertilization and compost.

In 2010, Silver Thread's viticultural regimen was strictly organic. Some readers might be surprised to learn that there is an as-organic-as-possible vinifera vineyard in the Finger Lakes, but Figiel is not going to be the one shouting from the rooftops.

In fact, if you weren't looking for it specifically, you might not even know it was there.



Further Reading:

Dell et al., "The Efficacy of JMS Stylet-Oil on Grape Powdery Mildew and Botrytis Bunch Rot and Effects on Fermentation", AJEV, 1998

Resource Guide for Organic Insect and Disease Management: Oils http://www.nysaes.cornell.edu/pp/resour ... 09oils.php