Vineyard & Winery Management Magazine
Feature Story
The Science Behind BiodynamicsDo academic trials back up growers' glowing testimonials?
By Jamie Goode
Biodynamic farming has achieved a level of respectability in the wine community that belies its rather strange roots. This form of agriculture, which has been widely adopted by leading winegrowers in some regions, such as Burgundy and Alsace, has its origins in a series of lectures by Austrian polymath Rudolf Steiner. Steiner's speeches, given shortly before his death, in 1925, shared concepts he developed not through experimentation or careful study, but through clairvoyance.
If this doesn't set alarm bells ringing among readers, then some of the principles behind biodynamics - specifically, those that differentiate it from organic farming - sound decidedly unscientific. For example, the preparations used in fields include cow dung, buried in a cow horn for a season; silica buried in cow horns, and flower heads of yarrow fermented in a stag's bladder - all of which are diluted and dynamized (stirred in a special, complex way) before application. The timing of interventions is also determined by a calendar that is alarmingly astrological in its conception. Indeed, biodynamics has been described as "Harry Potter does viticulture."
Why is biodynamics taken so seriously, then, if it is so weird? The simple answer is that it's the reputation of the producers who have adopted it. The roll call of winegrowers employing biodynamics includes some star names: Paul Dolan, Randall Grahm, the Benziger family. You could drink very well, indeed, if all you were to consume from this point onward were wines made from grapes grown biodynamically.
Frequently, producers already making good wine have switched from conventional viticulture to biodynamics and have seen an improvement in quality sufficient to convince them to switch their entire production to this way of farming. It is this plausible testimonial from people making world-class wines that has achieved for biodynamics the credibility that it now holds in the wine industry. In the United Kingdom, for example, a number of the leading supermarkets (which sell the majority of the wine in this market) hold their press tastings on the appropriate days in the biodynamic calendar when wine is supposed to taste best. The organizers may not be true believers, but in hedging their bets like this, they confer a high level of professional respectability on biodynamic farming.
But what does science have to say about biodynamics? Most scientists ignore biodynamics, because in their eyes the claims made are so outlandish, and couched in such non-scientific terms, that it simply isn't worth addressing them.
"Organic farming owes its origins in part to the development of biodynamic farming by Steiner," acknowledged leading plant biologist professor Tony Trewavas (University of Edinburgh, UK), in a review published in the journal Crop Protection in 2004. "However, this form of farming, with its belief in cosmic forces, has no place in any scientific discussion and is considered occult in character."
BIODYNAMICS ON TRIAL
This sums up the attitude of many scientists toward biodynamics. A few, however, are intrigued by the grower testimonials. Intelligent, competent, honest winegrowers are seeing benefits in their vineyards that translate through to their wines. Is this simply some sort of placebo effect, whereby the practice of biodynamics encourages people to work more diligently because they have bought into a philosophy that acts as some kind of motivational tool? Or are some or all of the claims of biodynamics, odd as they sound, explainable in scientific terms? To this end, a number of trials comparing biodynamics with other methods of farming have been attempted. We will come to these in a moment.
Most biodynamic growers have little interest in scientific trials. While many of them take a look-and-see approach before committing their vineyards to biodynamics, they are often sufficiently convinced by their experience not to require firm data to back it up. Generally, they will adopt the entire suite of biodynamic tools and practices, rather than pick and choose which elements to implement. This means that very few people have the motivation to conduct scientifically credible trials to examine the effects of the different elements of biodynamic farming.
Those who oppose biodynamics can't see any plausible way that these practices could work, so they also lack the motivation to do the required trials. There are two other obstacles in the way of rigorous research on biodynamics. First, because biodynamics sees the whole farm as a single "organism," the idea of separate, adjacent plots being farmed by different methods, in a trial-type scenario, doesn't really fit. A second difficulty is persuading research-funding agencies to pay for these studies, should the will be there to do them in the first place. John Reganold, a scientist at Washington State University who is one of the leading authorities on organic agriculture, told me that some of his research proposals have been vetoed by funding agencies because they have contained the word "biodynamics." "Many scientists won't even look at biodynamic farming systems," he said.
Biodynamics is certified by an international organization called Demeter, but for wine, there is a second certifying organization, Biodyvin, based in France, with 52 members at the time of publication. (Typically, biodynamic winegrowers will get certification from either Demeter or Biodyvin, plus an official organic certification such as from Ecocert.) Biodyvin has commissioned a series of studies on biodynamics, yet results have not been published in peer-reviewed journals (the usual method of communicating scientific findings). Instead, these studies, on a variety of topics, are published on Biodyvin's own website (www.biodyvin.com). While Biodyvin's attempts to look at the efficacy of the various treatments is commendable, the organization would be much better off if its studies were designed by academics and published through reputable scientific journals. Non-peer-reviewed studies lack scientific credibility.
The key challenge for research on biodynamics is this: to show that the use of biodynamic preparations and the timing of their application has efficacy beyond organic farming. While in theory, biodynamics is quite different from organics - for example, biodynamics includes the notion that the farm is a whole "living" system, and the putative existence of life forces that influence plant growth - in practice, it looks very like organic farming with some extra elements added in. The notion of encouraging soil health through the use of composts and the benefits of no-till agriculture have a sound scientific basis. Does biodynamics give a grower anything more than the application of organics would? This is the central question.
ACADEMIC STUDIES
There have been a few academic studies of biodynamics, and some have found their way into scientific literature. In 1993, Reganold and colleagues compared the performance of biodynamic and conventional farms in New Zealand, and a report was published in the leading scientific journal Science. They found that the biodynamic farms had significantly higher soil quality, with more organic matter content and microbial activity, yet this doesn't show the efficacy of biodynamics over organics. In 1995, Reganold published a review of the various studies that had examined biodynamics, and which had met basic standards for scientific credibility. The conclusion was that biodynamic systems had better soil quality, lower crop yields and equal or greater net returns per hectare/acre than their conventional counterparts. Again, these gains could have been achieved by the organic, scientifically plausible component of biodynamics.
Lynne Carpenter-Boggs, a student of Reganold's and now a Ph.D researcher at Washington State University, looked at the effects of biodynamic preparations on compost development. In an experimental setting, biodynamically treated composts showed higher temperatures, faster maturation and more nitrate than composts that had received a placebo inoculation. However, these results were not published in a peer-reviewed journal. In a paper Carpenter-Boggs did publish with Reganold in 2000, they found that organically and biodynamically managed soils had similar microbial status and were more biotically active than soils conventionally farmed (that is, they had more life in them), but that while organic management enhanced soil biological activity, the additional use of the biodynamic preparations did not significantly affect the soil biotic parameters tested.
In May 2002, the results of a 21-year study comparing organic and biodynamic farming with conventional agriculture were published, also in Science. A group of Swiss researchers, led by Paul Mäder of the Research Institute of Organic Agriculture, showed that while biodynamic farming resulted in slightly lower yields, it outperformed conventional and organic systems in almost every other case. The biodynamic plots showed higher biodiversity and greater numbers of soil microbes, and more efficient resource utilization by this microbial community. However, this was general farming, not viticulture.
"This appears to be the sort of detailed, long-baseline work we are after," state Douglass Smith and Jesús Barquín, in an article addressing the credibility of biodynamics in The World of Fine Wine (Issue 12, 2006). "But buried in the supporting material, only available online, is the methodology behind the study. There we find that the biodynamic and organic farms began with composts prepared differently. Certain chemicals were added to the organic fields that were not added to the biodynamic ones. And these were only the ‘main differences.' What were the others? We aren't told." Smith and Barquin conclude that the results from Mäder's experiment may simply be due to differences in the original composts or in the chemical additions to the organic plots.
Perhaps the most interesting study, however, is the research conducted by Jennifer Reeve for her master of science thesis in 2003 (this work was published in 2005 in the American Journal of Enology and Viticulture). Titled "Effects of Biodynamic Preparations on Soil, Winegrape and Compost Quality on a California Vineyard," the thesis was supervised by Reganold, and looked at the same merlot vineyard in Ukiah, Calif., over a seven-year period (1996-2003).
Two treatments were compared in this 12-acre vineyard: organics, and exactly the same management, yet with added biodynamic preparations. The biodynamic field sprays (cow dung buried in a cow horn for a season, silica buried in cow horns, and barrel compost) were not shown to have any effect on soil quality, and analyses of the grapes showed surprisingly few differences (over the seven years of the study, the biodynamic treatments resulted in significantly higher tannins in 2002 and Brix in 2003, but these were the only significant differences). Nutrient analyses of leaf tissue, clusters per vine, yield per vine, cluster weight and berry weight showed no differences.
BENEFITS BEYOND ORGANIC?
Overall, from the few studies that have been carried out, there seems to be little support for the efficacy of biodynamics beyond the benefits of organic farming. But we need to bear in mind that (1) biodynamics is very difficult to study in a trial environment, because there are so many variables to look at; and (2) there have been precious few scientifically credible studies devoted to this topic.
Some of the spray preparations unique to biodynamics could be having an effect that is scientifically explainable. For example, they could be acting as microbial inocula, seeding the vineyard with tiny but significant levels of microbes that could then colonize the soil and vines. Or some of the tea sprays could be enhancing the vine's resistance to disease through inducing systemic-acquired resistance.
Besides, it would be foolish to discount the placebo effect of such treatments, if by buying into the philosophical system of biodynamics, growers are developing a deeper relationship with their vineyard, and are working more diligently because of this. It's too soon to conclude that biodynamics has no scientific basis, but the evidence so far does seem to suggest that certain elements of it (such as the common parts it shares with organics) are likely to be more efficacious than the more esoteric components.
RESCUED VINEYARDS
For sake of balance, though, we need to mention a phenomenon that seems to support the efficacy of biodynamics, and which hasn't yet been explored scientifically: that of "rescued" vineyards. Of course, these accounts are anecdotal and are delivered by advocates, but there is little reason to suppose that they are lying.
Anne-Claude Leflaive of Domaine Leflaive reports that the domaine's plot in Bienvenues-Bâtard-Montrachet was "rescued" through the use of biodynamic practices. In 1990 the then, 30-year-old vines were in bad health, and they were subject to replant. The leaves were chlorotic and the wood was small; the vines had been yielding badly. Leflaive and Domaine Leflaive team member Pierre Morey decided to do an experiment on these "lost" vines. They stopped using herbicides, opened up the soil and employed the biodynamic preparations. "We were the first to be astonished by the response of the vines to the new treatment," she said. "Now these vines are the oldest of the domaine, more than 50 years old."
In the Napa Valley, leafroll virus is a problem that has caused many vineyards to be replanted before they are 20 years old. Ivo Jeramaz of Grgich Hills Estate recalls how a 50-year-old vineyard in Yountville, Calif., that now yields his best cabernet sauvignon came within a whisker of being yanked out of the ground. "We had very low yields and the vineyard couldn't ripen properly," said Jeramaz. "We'd be lucky to get to 22 Brix and the grapes were pink." Instead of replanting, Jeramaz cultivated the vineyard with biodynamic principles. The results were that the heavily virused vineyard suddenly sprang back to life. "After three years the vineyard had rebounded dramatically, and it now makes our most expensive cabernet. There are fewer red leaves and the vineyard wants to go to 30 Brix."
Barry Wiss of Trinchero Napa Valley reported a similar experience in the winery's 23-acre Chicken Ranch vineyard in Rutherford. The cabernet sauvignon vines in this vineyard had a bad leafroll virus problem, and within a few years of biodynamic farming this was reportedly cured. This sort of reversal could easily be examined scientifically - and the results might even help convince the skeptics.
"What we see when looking over the biodynamic landscape is a vista of starry eyes and good intentions mixed with quasi-religious hocus-pocus, good salesmanship and plain scientific illiteracy," concluded Smith and Barquín in their article presenting objections to biodynamics. "It is the esoteric, occult aspects that give biodynamics its originality and raison d'être. Get rid of the esoterica, and it is not clear that any point remains for the small industry of consultants, conferences, press articles, books or fanciful homeopathic dilutions."
Jamie Goode is a London-based wine writer specializing in wine science and technology issues. He writes a weekly column for a national newspaper in the UK, publishes www.wineanorak.com and is columnist for The World of Fine Wine. Before turning to wine, he worked in science and has a Ph.D. in plant biology.
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