Organic vs. Biodynamic Part 2, the soil

A very interesting aside in the 2005 ASEV paper “Soil and Winegrape Quality in Biodynamically and Organically Managed Vineyards” is that an annual ryegrass green manure crop was cultivated into the soil in 1996 and in 1997 the vineyard was composted:  “organic matter spiked in 1997 and then fell back to pre-compost levels by 2000.”  We don’t know how much or what the material was, but composting lasting only three years is consistent with my experience.   My reading of Biodynamic literature indicates great emphasis is placed on soil building, with composting and “preparations” as the main ingredients of that program.  Composting appears to be the main vehicle for adding Nitrogen to the soil for the growing of Biodynamic crops.  Certainly modest levels of composting will enhance the soil organic matter and in my experience the study’s results showing about a three year enhancement is about right for a single treatment.  But modest levels of manure compost may not provide sufficient Nitrogen for that farm.  IMO, Biodynamic principles are at risk here because the notion of a self-contained, composted farm is simply not practical without bringing in large amounts of compost and manure from other sources.  The Demeter Association allows up to 100 lbs of Nitrogen per acre under normal conditions and up to 150 lbs. of Nitrogen with “inherently nutrient-deficient (farms)…”  To add 100 pounds of Nitrogen with a 2% Nitrogen content requires 5,000 pounds of compost per acre per year.

 Here’s what I’m getting at: a vineyard produces shoots, leaves, stems and berries.  At Smith-Madrone the canes are chopped and returned to the soil, the leaves fly wherever the leaves want to fly, the stems are composted and represent about 5% of the total weight and the pomace is returned directly to the vineyard with only the grape juice being permanently removed.    However, the amount of pomace we generate and return to the vineyard is quite small when compared to the entire vineyard.  While it helps with sustainability, our pomace is not sufficient to build “healthier” soil.  One ton of grapes contains about 200 gallons of liquid (we get on average about 165 gallons out of the press with the rest going back to the vineyard with the pomace); this leaves an estimated 300 pounds of dry weight pomace and stems. That 300 pounds times our three tons to the acre results in a whopping 1/3 ounce of pomace and stems per square foot of vineyard.  Look at it another way; what is 900 pounds of pomace in the top six inches of soil when the average top six inches of soil weighs 2 million pounds per acre?  

 I suspect our cover crop produces more dry weight organic matter than the pomace and our prunings provide even more organic matter.  However, since we are a non-till vineyard all three sources of organic material must decompose slowly on the surface as opposed to being disked or plowed under the soil where the microorganisms have an easier way of getting to that organic material.

 Gardeners compost at rates that would be multiple times what our vineyard generates, maybe even hundreds of times greater. So you can see that while returning everything to the vineyard in a closed system may be sustainable, it means very little to building a healthier soil. That’s fine with me because I believe that soils are, by my definition, inherently healthy and need only an adjustment or so.

 But there is the problem of how to define a “healthy” soil?  Most farmers would agree that Class 1 Yolo Fine Sandy Loam may be some of the finest soil on earth.  But when we think of premium wine grapes those are not the soils of choice.  Gravel, rocks, bench, upland, mountain, mineral, low fertility and well drained are words that define great vineyard soils. One soil is superior for traditional crops and the other soils are superior for unique agriculture such as wine grapes.  Are the deep, rich and fertile soils healthy and the rocky, gravelly mountain soils un-healthy? 

 The paper also touches on the issues of soil fertility, soil depth and root penetration—three very important issues for vineyards.  Grapevines are deep rooted and in the sandy soils of the San Joaquin Valley grapevine roots have been found at the 100 foot depth by water drilling rigs.  There are almost no roots in the top 12 inches because of either cultivation turning over the soil to that depth, or with non-till the permanent cover crop roots tend to get that moisture first.  So the effective rooting zone for most of our vineyards is the one to five foot depth: this is where the real action is happening, this is where the vine gets its moisture and nutrition, not in the top inches of soil.  So earth worms munching through the soil, composting and green manure are great for the shallow rooted plants but they do little for the deep rooted vines and trees.   Remember that compost and green manure take time to break down into a form that the plants can use.  Unfortunately, the timing is off because the nitrogen becomes available only in late summer when we want the vines to stop their vegetative growth cycle and start the ripening cycle.  It takes the winter rains to drive those released nutrients down into the root zone. 

 Growers spend a great deal of brain power trying to figure out which rootstock will match best with both the soil and the intended grape varietal. Could Biodynamics’ emphasis on soil building and health actually be misplaced and counterproductive to wine quality?  I believe the answer is yes, but to be fair, that yes answer would apply to any grower who tries to change the soil characteristics by using too much compost and green manure.  Here’s what could happen with too much compost:

  • Organic content becomes too high – 1% up to 4%
  • Water holding capacity increases
  • Nitrogen content becomes too high
  • Potassium content becomes too high
  • Soil acidity becomes too low
  • Calcium and Magnesium become out-of-balance
  • Vine growth becomes too vigorous, especially in the short run
  • Vine growth becomes out-of-balanced
  • Natural soil system is disrupted
  • Rootstocks no longer match original soil conditions
  • Wine quality suffers
  • Grower now thinks soil is “healthy”
  • Grower is now polluting the environment

Soils have natural levels for nutrients, and if some of those nutrients like Nitrogen exceed the background levels then pollution begins.  Organic matter breaks down into the negatively charged nitrates which are easily leached from the soil and this is an especially harmful pollutant near water sources.  Phosphorus has similar issues.  Small amounts of manure compost to help with the soil organic matter may be helpful as one of many tools available to the farmer, but relying on the manure compost as the sole source of nutrition and Phosphorus can result in problems.  If I believe our vineyard or cover crop needs Nitrogen then I think it is more responsible to add just what is needed – it is the rifle vs. the shotgun approach.  And after all, the Nitrogen we use comes from the air, not from oil by products. 

 Why are we messing with Mother Nature anyway?  Why are we trying to make a sow’s ear into a silk purse, when the sow’s ear makes great wine and the silk purse doesn’t?  What happened to the idea that wine grapes should struggle in poor, rocky, well drained soils? Historically, it was the wine crafted from those difficult soils that gave us wines of distinction, character and uniqueness – what I call a sense of place and what others call terroir?

Stuart Smith

19 Responses to Organic vs. Biodynamic Part 2, the soil

  1. Cookie says:

    Organic does not mean anything anymore it’s an excuse for Big Food to enter the market and obtain the coveted green and white label and then charge double the price. All this whilst diluting the standards of “Organic” It is organic that is the hoax and this article is in defense of it because the author knows that Biodynamic is the real dea.

    • biodynamicshoax says:

      I feel your pain! While it’s true that organic has gone main stream and big business has learned how to cash in on the world-wide “green” hysteria, and I find many, many flaws with organic farming, it is still a viable alternative farming method that challenges the conventional wisdom and has value in the short to medium term. On the other hand, Rudolf Steiner was a con-artist and a fraud that spoke with the dead and created the hoax what so many soft-in-the-head folks call Biodynamics.

      Sorry Cookie, we just see the real world differently.

  2. Bill Dyer says:

    Stu, you wrote above: “Don’t forget that there is no Biodynamic produced wine. Biodynamics is limited to a defined farming method, which, of course, I think is bunk. Winemakers are free to treat the Biodynamically grown grapes in whatever way they feel will make the best wine, within state and Federal rules.”

    However, a spread sheet was passed on to me that was represented as outlining the specific practices Demeter requires for a certification category for “Biodynamic Wine” as opposed to “made from Demeter Biodynamic Grapes” and contrasts both categories with label requirements for “Made from Organically Grown Grapes.” I would post it here but I can’t find a way to copy an Excel spread sheet within this blog site. But the essence is that “Demeter BD wine” and “Made from Demeter BD Grapes” both prohibit nutrient additions other than yeast hulls or other organic ingredients; both prohibit fining agents other than BD/organic eggs: both prohibit copper sulfate; both require indigenous yeast (though there is a waiver for stuck fermentations in “made from BD grapes,” not BD wines); both require indigenous ML (though there is a waiver for new wineries and for stuck MLF in “made from BD grapes,” not for BD wines. The following are prohibited in BD wines, but allowed in “made from BD wines”): chapitalization, and water adjustment of brix. Tartaric addition of up to 1.5 g/L is allowed in “wine from BD grapes,” not in BD wines. Micro-ox is allowed in “wine from BD grapes,” but not in BD wines. No tannins or enzymes are allowed in either case. BD wines must be Estate, no such requirement for “from BD grapes”. Bentonite is allowed in either case. This spreadsheet was made available by a person representing Demeter to a winery considering submitting to their certification. It was not represented as being proprietary. I presume this information must be public information. I think there is also a difference in fee structure for the certification of the two categories, but I don’t have this information in front of me.

    • biodynamicshoax says:

      Sorry for tardy repley – getting some vacation time in! I didn’t know about the Biodynamic wine certification, wonder if it’s a new marketing ploy by Demeter, or if I just never ran across it in their literature? Also, I have a question that I’m trying to answer: It appears that to be Demeter certified, you must first be organic certified, and that Demeter accepts organic standards for what is allowed to be sprayed/dusted in the vineyards – is this correct? If a product is approved by the organic group, is it automatically ok for Biodynamic growers? The Demeter website is vague on this point – they are forceful in rejecting foreign organic products, but are silent on domestic organic products.

    • Bill Dyer says:

      My understanding is that the Demeter organization in Oregon accepts the organic standards of any organic certification organization that is recognized by the USDA.


    • biodynamicshoax says:

      Does that mean if OMRI (and the 50 others like OMRI) approve a product and or chemical for organic use it is then approved by Demeter?

    • Bill Dyer says:

      That’s the implication as it was explained to me by someone taking part in the Demeter certification process. But perhaps another reader who is Demeter certified (or from Demeter) would step in and answer this definitively.

  3. Graham says:

    Hi Stu
    Great website, thanks.
    Im wondering what your views on Aerated Compost Teas (ACTs) are, as promoted by Dr. Elaine Ingham:
    In some quarters it looks like people are claiming ACTs “prove” BD works, but a)ACTs and BD preparations are quite different; and b)there seems little evidence that ACTs do what is claimed for them either.
    Ive blogged about this here:


    • biodynamicshoax says:


      Only a quick look, but nice site and will spend more time there – thank you. I’m not familiar with ACTs but if they are similar to the Biodynamic teas then I’m very skeptica. I will look into them.

  4. This discussion is so cool. For someone who has been in the business for 20 years (on the sales side) but who has never taken a viticulture class or chemistry class past high school, this discussion is fascinating.

    What I particularly enjoy is how easy your writing is to read and understand and how engaging. Great work.

    I was wondering if I could ask a question about the difference between a “non-till vineyard” and a “tilled vineyard” and the pros and cons of each?

    Thanks and keep it up.


    • biodynamicshoax says:


      Welcome. Traditionally vineyards were “tilled” or “disced.” A disc has got a front axle with discs (think 22 inch diameter steel cupped dinner plates) and a rear axle with the discs facing the other direction. When the disc is open and pulled by a tractor, the two axles compete with one another and dig into the soil and turn the soil over. With several passes the cover crop is “turned under” and you see the dirt w/o weeds (mostly). There are off-set discs, which I just described, and a four-gang disc which is where the front axle is now two separate axles with the discs facing each other, same for the rear, this type allows more competing angles and thus is more effective in turning over the soil. I always preferred the off-set when we used it. We went to non-till in the mid-late 1970s.

      Discing has several advantages. It turns over all the cover crop and stops those plants from taking moisture from the vineyard. Discing also eliminates most summer weeds. If the disc has a wood or steel drag behind it, the soil will be both weed free and smooth. A smooth vineyard floor will absorb and hold the sun’s warmth into the evening and will provide several degrees of frost protection on a frosty night. Turning the soil over eases the cover crop breaking down into useable organic material. A clean, well disced and dragged vineyard looks well tended and professional (old school). Cultivating the soil during the summer is believed to “bring up” the moisture from deep within the soil through wicking – an advantage to dry farming. It’s a very effective fire break.

      The disadvantages: It takes a lot of horsepower and energy to turn over the soil and it may take three or four passes to accomplish the task. The later passes create lots of dust. There is more dust when the tractor goes through the vineyard for hedging, spraying and/or dusting with sulfur. If you don’t vary the cutting depth you can create a hard pan. Bare soil is more prone to soil erosion and bare soil is more prone to soil frost lift. Bare soil makes for higher summer time temperatures. It’s old school.

      Non-till is simply mowing the cover crop; it is also called a permanent cover crop. Think about mowing a lawn but not watering it. In the west the cover crop will die out.

      Advantages: Fewer trips through the vineyard and using less energy because you’re pulling the mower above the soil and not through it. Great soil erosion prevention. The cover crop germinates and grows faster because of the thatch (think dead lawn). That thatch also eliminates frost lift, which is where with early frosts, the ice lifts the seedling up and out of the soil and thus kills the seedling. Reduces dust to almost nothing which also reduces wear on equipment and is much easier on the operator and helps with pest control. Can help with soils that are overly fertile by reducing water availability. Results in cooler summer temperatures. It’s new school and more environmentally sensitive.

      Disadvantages: The grower has to get used to a messy looking vineyard and re-program conventional thinking about what a “professional” looking vineyard should look like. Summer weeds can become a problem. Tends to take more water from the vines, harmful to dry farming. Tends to provide more cover for rodents which in turn can increase rattlesnakes. Vineyard is now vulnerable to fire – there is no fire insurance available for the vines.

      Hope this helps.

  5. Donn R says:

    My question: if some of the best wines are grown in these rocky turfs with very little actual dirt or loam, then, does a vineyard stay that way for centuries, does it not need compost and organic material, and maybe, the only human role, is to NOT introduce added chemicals in the form of “fertilizer”. I am curious as to why the Burgundy vineyards existed for hundreds of years, yet, we are recently taught, that the use of chemicals in the last 50 to 100 years had negative impact on the vines, and hence the wines from these ancient sites. What is the real key to whatever benefit we actually derive from organic farming? Is it to refrain from adding chemicals, or is to actually add carbon based compost and manure?

    • biodynamicshoax says:


      Your question goes to the real heart of the matter. There are vineyards in Europe that have been continuously, and apparently successfully, farmed since the days of Rome. I would suspect that over such a long time frame certain nutrients may become depleted and some sort of supplement should be added.

      I don’t agree that chemicals are the downfall of vineyards anymore than I think that irrigation is bad. Some vineyards need more chemicals than others and some vineyards need water and others not. Most of these decisions come down to economics. If you’re growing Zinfandel grapes in the Sacramento Valley which are intended to sell at $5.99 then you’re going to fertilize and water the hell out of them and hope for 20 plus tons to the acre. If you’re growing on top of a rocky mountain and the wine is intended for the ultra premium collectors’ market then you might keep your crop to three tons or less, dry farm and use as little fertilizer as possible.

      Farmers, like most folks, tend to think if a little is good, a lot is better. I know this to be the case with irrigation and I suspect that was the case when fertilizers and pesticides first became available. We learned from our mistakes and that misuse is not the case today. Just the word chemical has a negative impact for most people, yet the plants don’t know, or care, if their nutrients (chemicals) come from the air, animal manure, green manure or a factory.

  6. Ron Rusnak says:

    Stu: great stuff!

    Question: With high consumer ‘concern’ about ‘sulfites,’ why do you feel so many organic and bio-dynamic producers quietly continue to add sulfiting agents as a necessary for stability and minimizing continued oxygenation?

    Not only is it hard to explain ……but many consumers (and few prodcers) seem to feel that it flys in the face of the bio and organic creedo (depite sulfintes being a ‘natural’ element).


    Ron Rusnak

    • biodynamicshoax says:


      I have lamented the lack of good research on allergies and headaches attributed to red wines for as long as I’ve been in the wine industry. Some feel it comes from the tannins and others believe it comes from the sulfites. When I was younger I used to think that the headaches came from liking red wine too much and hence drinking too much of it the night before. I wish I knew more.

      You bring up a great question which I can only inadequately answer. Most of us know that sulfites are naturally produced in small quantities during fermentation, but the real answer is that sulfites allow us to make better wine. I am not particularly satisfied with the various “reasons” that most of us parrot, but that is what we do. I’m all ears.

      Don’t forget that there is no Biodynamic produced wine. Biodynamics is limited to a defined farming method, which, of course, I think is bunk. Winemakers are free to treat the Biodynamically grown grapes in whatever way they feel will make the best wine, within state and Federal rules. I am not sufficiently knowledgeable about organic winemaking to offer an opinion as to whether sulfites are consistent with the organic philosophy – sorry. But, again, it’s a great question.

  7. Tim M says:

    This is a complex topic (What is soil health anyway?), but you seem to be talking out of both sides of your mouth on this one. On the one hand, you argue that compost additions last for only 3 years anyway (but don’t supply enough N, and what they supply is released at the wrong time), and on the other that ‘soil improvement’ from added organic matter could mess with the ‘terroir’ by making the soils too fertile. Does this jibe with biodynamic ‘rates’? I think the numbered preparations can be discounted (silica, the cowhorn stuff), as they are applied at homeopathic dilution rates. That leaves prunings (2 lb grown pruning weight per vine @ 1,000 vines/acre would be 1 T organic material,or 0.1% of the 2M lb of soil/acre in top six inches)and the compost. 5T compost/acre would supply 10,000 lb/acre OM = 0.5% of the 2M – but this of course doesn’t translate into raising the organic matter by anywhere near that amount. My guess would be <<0.1% net,which would mean that 10 years of every year application would be needed to bump up organic matter by 1%. It takes a while to do this – and wouldn't it be possible that BD growers might adapt rates and timing to avoid going overboard with this? (does the compost have to be totally 'manure based'?) If N content of compost was 0.5%-1.0%,5 T would supply 50-100 lb/acre, but of course not all released at once.

    Bumping up OM and water holding capacity might have positive impacts – for example it might allow the grower to 'dryland' farm as opposed to irrigate.

    But would adding organic matter (even to excess) convert a gravelly hillside soil into a fertile, deep Yolo fine silty loam? Probably not. It's not going to alter the soil depth, drainage or overall water holding capacity – even if it modifies that top six inches.

    In short – I think one would have to really apply excessive inputs over several years to really mess up the soils to the extent you are arguing.

    And why repeat the old saw about 'vines have to struggle'? Is that what the science tells us? Or is it that water relations (and especially ET deficits from bloom to verasion) moderate shoot growth, resulting in an open canopy that impacts berry size, aromas and flavors, etc?

    • biodynamicshoax says:


      Agreed, it is a complex subject. Maybe I wasn’t as clear as I should have been. In the ASEV paper, I speculated that the onetime compost application was applied more as a general soil amendment for the organic material and not specifically for Nitrogen uptake. However, it is an entirely different matter if the farmers’ main source of Nitrogen comes from annual composting. We have to speculate on the compost material and percentages; is it mixed with poultry, cow or horse manure and in what ratio? Compost w/o manure is much lower in Nitrogen. However, annual manure composting can quickly get out of balance even in moderate amounts, especially when mixed with manures. Predicting the amount of Nitrogen released annually from compost is not simple – what is the real moisture level of the compost, is it a dry year or a wet year, did it break down quickly or not, were there sufficient rains to move the Nitrogen into the root zone and at the right time? As most of us know, we humans like to think if a little is good, a lot is better. If I may generalize about Biodynamic farmers, I tend to think that many of them are relatively new to farming and as such don’t have a solid grounding in soil chemistry and nutrition – of course I can be wrong.

      As I’m sure you know, most of the vineyards in California are mono-crops and not farms in the older sense with mixed uses. The only form of agriculture that can compete with housing in California is wine grapes and having a mixed use farm is just out of the question economically. Napa Valley vineyards sell (or did) for $250,000 per acre or more; devoting such land to chicken, cows, hogs and horses for their manure is just not in the cards. So I have to ask the question, if the vineyard doesn’t produce sufficient organic matter to provide the annual Nitrogen needs, where will the additional organic material come from, and doesn’t that suggest the close system concept of Biodynamics as unworkable?

      We both agree that no amount of money or amendments of any kind will turn a class III soil into a class I soil. However, it’s not that difficult to over supply organic matter, especially with a high manure content, and get into an adverse chemistry problem affecting both vine growth and pollution.

      While it may be more difficult, it is my belief that most soils can be dry farmed if the grower decides to do so. Historically vineyards have always been dry farmed; it is only in recent times that irrigation of vineyards became common practice. I remember when most vineyards in the Napa Valley were dry farmed and it wasn’t until the early 1970s that drip irrigation was first introduced from Israel.

      I stand by my statement that the best wines come from vines that have to struggle; that is the conventional wisdom of the ages and is still the generally accepted standard. That having been said, all conventional wisdom can and should be challenged, so have a go at it, but I think it will be infinitely more difficult for you than my skepticism of Biodynamics.

    • Tim M says:

      Thanks for the response. I agree that BD farmers would have to import organic matter from elsewhere (one of your major points)- and also that it’s possible to oversupply N and mess up your soils for a few years (at least) with excessive compost.

      This may be a little off the BD focus, But hasn’t there been a lot of science getting at the mechanisms behind the ‘vines must suffer’ idea? Don’t we have a more specific, science-based idea of what is going on? My understanding of this is that much of what is referred to as ‘terroir’ boils down to water relations – how much is available to vines and when. Dr. Kees van Leeuwen has done a lot of work on this in Bordeaux – and if I recall correctly, he spoke about the desirability of water deficits and moderate stress in controlling vigor roughly between bloom and veraison – and that a vine’s water status explained a lot of the ‘terroir’ effects.

      I also recall a presentation from a study done in a large eastern WA vineyard, where deficit irrigation between bloom and veraison was enough to regulate vigor and eliminate the need to hedge and leaf pull-and produce much better wine.

      Third example is a speaker from Napa who had a single block straddling a hillside (high quality) vs valley floor (low quality) – who was able to raise the quality of the valley floor grapes by eliminating every other vine and extending the cordons farther – thereby managing the excess vigor.

      Maybe this doesn’t speak to the best, most elite sites, but there are plenty of metrics describing shoot density, cane length and diameter, and vine spacing that ultimately express themselves in optimum canopy density, light interception, and leaf area to fruit ratios-in other words ‘vine balance.’ Much of which is mediated by water status and soil fertility/depth.

      So my intent wasn’t to dispute the general truth of the ‘vines must suffer’ conventional wisdom, but rather to suggest that there is a large body of science (of which you undoubtedly have a deeper understanding than I do) that offers explanations of why this might be the case. Besides, vines only really like to suffer up to a point- I’ve seen enough drought stress and its impact to be convinced that stress at the wrong time and intensity can damage vines.

      Thanks for your time and effort in managing this blog, which I greatly enjoy reading.

    • biodynamicshoax says:

      I think you are mostly correct on a subject that is still more conjecture than fact. If you’re willing to accept the premise that not all vineyard sites, soils and climates are capable of producing fine/great wine, then the next question should be how can we we improve quality, and that’s where those studies come in. Manageing water, growth and crop seize are important for how you define your goal in viticulture. Sutter Home farms a vineyard in the Sacramento Valley for their White Zinfandell program and feel 14 tons/acre is a crop failure. Some of us in the mountains feel 3 tons /acre is a banner year, but if you’re on valley soil and produce average quality Cab grapes and your winery rep says they need better quality or you need to find a new home, then working with water availability is a sound practice.

      I think we agree about the notion that vines must suffer to produce great wine when the goal is ultra-premium wine grapes. Mountain viticulture inherently provides most all of the limitations necessary for high quality grape production, whereas valley grapes don’t have those limitations – and it is the exceptions in both areas that make for so much verbiage in the press.

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