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Sun and Air

In discussing plant growth we tend to focus on soil factors, and forget that without sun and air there would be no plants at all. The sun provides the primal energy for photosynthesis, the only truly original manufacturing process on Earth. Air provides the carbon dioxide necessary for photosynthesis to occur, as well as nitrogen that is brought into soils by independent azobacter bacteria, and rhizobia bacteria in conjunction with plants. We must also remember that plant leaves can take in other nutrients from the air – all elements are present in air, in minutest quantities. We still don’t understand how relevant this is to plant nutrition, although the fact that leaves can take in nutrients has been abused by proponents of foliar feeding, who apply nutrients via foliar sprays, thus subverting the natural, sun-directed plant feeding process.


Professor Kervran makes the point that in agriculture, for biological transmutations to work, the soil must be alive, rich in microorganisms, and that adequate humus must be present. He also comments that all plants are different. For instance, some plants can make their own calcium in a calcium deficient soil whereas others can not. The same applies to other major and minor elements. Each plant has different root types and structures, and releases different exudates from its roots. Each plant lives in, fosters, and is fostered by, a unique community of bacteria and fungi.

We simply don’t know how many different species of living things are in the soil or understand the complex interrelationships that exist, or how they vary from plant to plant. We don’t know the full range of enzymes and coenzymes that are produced by plants and soil macro and micro-life or the biological transmutations they, the micro-organisms and possibly creatures such as worms might foster.

There is no question that the correct use of properly made and stored Biodynamic preparations enormously enhances soil biological activity. Organic matter levels in soils rise significantly. Microbial activity is greatly enhanced, root growth fostered[1], and colloidal humus formation promoted. As a direct result of this enhanced activity, soil colour darkens progressively, and soil structure improves. It is actively growing roots, in conjunction with soil biology that create and develop soil structure. Soils become deeper, even heavy clays becoming friable soil in time. Such dramatic soil changes, which soil scientists have stated would take Nature alone thousands of years to achieve, have only been achieved through the use of the Biodynamic preparations.

The soil spray 500 is a very concentrated source of microbes, as are the six compost preparations which are used in compost heaps and added to 500 to make the even more potent “prepared 500”. Dr. Pfeiffer, who was entrusted by Rudolf Steiner with researching the best ways of making and applying the BD preparations, discovered several novel microbe species in them. Sprayed on moist soil that is not too cold, the BD preparations have a unique and dramatic soil enlivening effect. The conditions for a rich soil ecosystem are well and truly established by their correct use.

Hand in hand with the use of the Biodynamic preparations goes a wide range of agricultural practices that have been developed since the late 1940s by Alex Podolinsky and the farmers of the Bio-Dynamic Agricultural Association of Australia. The whole focus of the Australian Demeter Biodynamic method is to foster the development of soil conditions that best enable the soil ecosystem to work at optimum effectiveness, resulting in the most vibrantly healthy, nutritious and delicious food. Some of the main Biodynamic agricultural practices are:

Rotational Grazing of Biodiverse Pasture

Pasture is divided up into many paddocks, at least five on a small farm, or up to thirty five or forty on a dairy farm. Stock are rotated regularly so that after a pasture is eaten down, it has time to grow back to an optimum height before again being grazed. After each grazing, many plant roots die, and are devoured by the soil life. Worm tunnels are created, which are again occupied by roots. The pasture roots go progressively deeper under rotational grazing, hand in hand with soil structuring and aeration. After grazing by cattle, pastures are harrowed (usually with split truck tyre “smudgers”) to spread the valuable manure, a form of “sheet composting”. The thinly spread manure is quickly digested and incorporated in soil humus by worms and microbes. Harrowing is not necessary if dung beetles are active, and is avoided when soils are wet enough to risk compaction by tractor tyres.

There is no doubt that permanent pasture is the best use of land for the development of the soil in terms of biological activity, soil structure, depth, and humus development. Peter Andrews, in his book Back From the Brink[2] describes a visit to one of the top racehorse stables in England in the 1960s. He complimented the manager on his pastures saying that they appeared to be free of weeds. The manager was obviously upset by this[3], and Peter later discovered that traditional English horse breeders considered that a good horse breeding pasture should contain at least 80 species. If the pasture had less than 40 species, it was considered to be in decline. When Peter had a closer look at the pasture he found many species of weeds there, in large numbers. The other essential was that pastures should never be ploughed, as experience had shown that when a pasture was ploughed, it would be no good for young horses for five years and would not produce a Group 1 winner for ten years. During the Second World War, English horse studs were compelled to plough their pastures to grow vegetables. When the militia arrived at this particular stud to make them comply, father and son stood at the front gate with shotguns until they relented.

Biodynamic pastures are composed of many species, the more the better, and weeds are generally regarded as useful contributors to the overall nutrition and biological activity of the pasture. Many “weeds” that would cause digestive disturbances or be avoided by animals on conventional farms, are relished and easily digested by animals on Biodynamic farms. Native grasses are also encouraged. Each plant species (including the “weeds”) brings a different quality to the soil, and benefits to the animals that graze. The large variety of species, each with its own unique biological activity, its own community of fungi and bacteria, enzymes and coenzymes, gives Nature a sufficiently varied palette to work with, to fulfil its aim of developing colloidal humus and bringing a balanced supply of nutrients to plants. Photosynthesis brings carbon in the form of sugars into plants and in turn into the soil. Legumes, in partnership with their co-working rhizobia, bring atmospheric nitrogen into the soil. Various herbs and “weeds” concentrate particular elements – for instance, heliotrope will flourish when copper becomes scarce, and is known to accumulate copper. Whether this is obtained from deep in the subsoil, or is in fact the result of a biological transmutation enacted by heliotrope in conjunction with its specific community of microorganisms and enzymes, is as yet unknown, but the fact is, it accumulates copper. In a biodiverse pasture, with a rich soil ecosystem and good humus levels, the transmutation of elements goes a long way towards providing a balance of nutrients to plants, and even though hundreds of tonnes of produce may leave a farm each year, taking nutrients with it, soils can continue to be productive for many years, despite no or only very low fertiliser inputs, as new elements are constantly being created from others.

There are limits however. Under current conditions, farmers have to export large amounts of produce to make a living, in contrast to European traditional organic farming of 150 years ago, whereby all farm wastes were conserved, and much of the production was retained to feed the extensive farm families. Only relatively small amounts were exported from the farm. Also, the European climate is much gentler and more conducive to no-input biological farming. In Australia, long drought periods depress biological activity and lower organic matter and humus levels. In practice, Australian BD farmers do generally have to import some non-water soluble fertilizers from time to time, albeit at considerably lower levels than do organic farmers, and vastly less than conventional farmers.

Soil Structure

Open, crumbly, friable soil structure is a fundamental aim of Biodynamics. Soil life (whose role is to turn organic matter into colloidal humus) functions best in a well structured, well aerated, well drained soil. It is soil life that creates well structured soil, through root activity, humus development and the creation of soil aggregrates (grown crumbly lumps). The proper use of well made BD preparations is instrumental in the creation of well structured, humus rich soil. Without BD preparations (also the use of poor quality preparations or the poor application of good preparations) soil development is far slower, and more fertilizer inputs are required to compensate for the less developed soil life, humus levels and structure.

Where existing sub-soil compaction exists, deep ripping (as first developed by Alex Podolinsky in the 1950s) is used in semi-dry soils to crack the subsoil and relieve the compaction, allowing roots and soil biology to extend well into the sub-soil.

The ability of roots to search widely and deeply in a well structured, well drained, biologically active, humus rich soil, is a major factor in the ability of BD farmers to produce high yielding crops year after year with minimal or no inputs. It also explains the fact that BD crops stay green for many weeks longer than conventional crops in a dry spell, often producing a viable crop in a drought whilst conventional neighbours’ crops fail.

Soil Cultivation

When soils have to be cultivated, the focus is on taking great care to disturb the soil structure as little as possible, and to avoid the creation of hardpans, or subsoil compaction. Soils should be slowly “broken” rather than cut. To this end, implements are chosen carefully: in general, tyned implements are preferred (such as the Rehabilitator plough[4], chisel ploughs, agro-ploughs, scarifiers etc.). Disc harrows or ploughs are acceptable if used with care in certain situations. Rotary hoes are very dangerous for soil structure, and require a high level of care and understanding. They are generally best restricted to shallow “chip hoeing”, to, for instance remove a dense grass mat before cultivation for a crop. Mouldboard ploughs can be used, but conventional mouldboards tend to create a hardpan, by cutting a “table top” under the soil. They are much better for the soil if a downward pointing tip is attached, to break the soil rather than cutting it. The Rehabilitator plough, made by Michael Fix (Victoria) is the state of the art Biodynamic plough, gently breaking and lifting soil, with low horsepower requirement.

Soils should never be overworked, but left in a rather rough state, only fining the top few centimetres if fine seeds are to be sown. Soil should never be worked too wet or too dry, and should always be worked slowly (no faster than a horse walks). Soil should never be “chucked”, or dust created. Tractors should be of as low weight as practical for the particular farm needs. Even when caterpillar tracks or balloon tyres reduce the weight applied to the topsoil per square centimetre, this is illusory, as the overall weight still presses as a whole on the subsoil, and can cause compaction.

Green Manuring

Green manuring is an invaluable way of providing humus for subsequent crop growth, whether it be vegetables, grains, berries, or in orchards or vineyards.

In Biodynamic green manuring, as in pasture composition, we aim to include a very wide range of species, with the leguminosae and graminaceae (grain) families predominating. Each plant species brings its own unique qualities to the mixture, its own associated community of microbes and fungi, its own root exudates, and associated enzymes. Each plant brings a different composition of elements and a different capacity to concentrate different elements, whether through biological transmutation or by the roots and associated soil life seeking out particular elements. One of the finest examples of Australian Demeter Biodynamics in Europe, Agrilatina Cooperative, Italy, uses up to 90 species in its summer green manures and up to 30 in its winter green manures.

Alex Podolinsky has suggested that there may well be a qualitative difference between an element contributed by one species and the same element contributed by another species, just as there is a qualitative difference between the C sharp played by a trumpet and an oboe in an orchestra. The richness of a very diverse green manure may contribute more to the soil and to humus in a qualitative sense than simply the sum of the elements it provides, just as an orchestra provides a richness and diversity of sound even when the same note is played by all instruments.

When the green manure is ready, it is cut up as finely as possible (best by a mulcher), and worked into the soil (best with a Rehabilitator plough, several times), where it undergoes in-situ composting, with the assistance of a prepared 500 spray. The following crop is planted or sown when the green manure has been broken down and converted into colloidal humus. The more diverse the green manure, the better balanced nutritionally will be the colloidal humus that results.

Weeds as Green Manure

Pioneered by Western Victorian Biodynamic farmer, Barry Edwards, this technique recognises that Nature will always try to bring balance into the soil. The ground is left to grow whatever wants to come, until the weeds, herbs and grasses reach their optimum development. While the plants are still green, they are incorporated in the soil, are broken down and converted into humus by the soil life. The subsequent crop always flourishes, as Nature has ensured that the wide array of plants that constituted the green manure would bring whatever elements were lacking in the soil. An additional benefit is that, as the weeds grew there to balance a deficiency, once that deficiency is rectified, they don’t need to grow there again for some time.

Under this system, Barry Edwards only needs to apply 3kg of phosphorus (non water soluble) per hectare per crop (2 crops in five years) compared with the 12-20kg (water soluble) applied by conventional growers. His crop yields are generally comparable with his neighbours’ conventional crops.

Biodynamic Compost

Is the perfect plant food, being 100% colloidal humus, and is an invaluable input in many situations, from home gardens to market gardens, orchards, berry farms, and dairy farms. It contains a wide variety of elements brought by the manure of grazing animals and the varied plant material used, and is a rich source of beneficial microbes.

We have here only considered factors involving the soil, air and sun. There is much evidence that plant growth and nutrition are also influenced by the moon, planets and zodiac star groupings. Some of these factors are employed to good effect by Biodynamic gardeners and farmers. However they are beyond the scope of this article.

The reason Biodynamics works so well is that every aspect of the method, based on scientific understanding, meticulous experiments and extensive field trials, is focussed on building and protecting the essential soil life, whose collective function in Nature is to convert organic matter and any free soluble elements into stable colloidal humus, which feeds plants as Nature intended, under the jurisdiction of the sun, not indiscriminately through the soil water. The Biodynamic preparations are the most powerful (and unique worldwide) stimulators of biological activity in the soil, and, when combined with associated biological agricultural practices, enable farmers and gardeners to produce food of the highest quality with absolutely minimal inputs.


By John Bradshaw

Thank you John for permission to reprint.

© Biodynamic Growing magazine, June 2010