Biodynamics - Report from the Biodynamic Conference

This document was prepared as hand-out for a Biodynamic conference held in 1998.

Biodynamics is becoming more and more widely known in New Zealand farming and gardening circles as an alternative to conventional methods of agriculture.

For many years a small band of enthusiasts has been saying that when you take up Biodynamic methods, you can expect to see marked improvement to the soil. In 1993, this was confirmed by the publication of a four-year study that compared carefully matched pairs of biodynamic and conventional farms. This report, by a team of scientists from Massey and Washington State universities, has become known in Biodynamic circles as "The Reganold Report", after its senior author, Dr John Reganold of Washington State University.

The report concluded that biodynamic farms have roughly the same financial performance as conventional farms, but much better soil properties. Here, the term includes market gardens and orchards, as these were studied along with mixed arable, drystock and dairy farms. The report measured seventeen different soil indicators, including some that your average soil test doesn't go into. Soil respiration is one of these.

Soil Respiration

Soil respiration is measured by how fast a soil sample uses up oxygen. That tells us about the micro-organisms in the soil - the more there are, and the more active they are, the more air they'll need to "breathe". So, a soil sample that uses more air is likely to have more microbes at work in it, and probably also more worms and other larger soil organisms. The Reganold study showed that the biodynamic farms generally had substantially higher soil respiration rates than the conventional farms, and this gives us a clue to the real differences between Biodynamic and conventional agriculture.

Conventional Farming

In conventional agriculture and horticulture, the grower often thinks about feeding the plant. This line of thought reaches its maximum development in hydroponics, where there is no soil and the plant is fed directly from a nutrient stream. It can also be seen in many other parts of horticulture - for example the use of diluters to feed glasshouse crops, or the widespread use of water soluble fertilisers in many branches of agriculture. It's well known that water soluble fertilisers, such as ammonium compounds, urea can be rapidly taken up by plants.

Biodynamic Farming

Biodynamic agriculture, by contrast, sets out to feed the soil, and the soil organisms. It treats the soil as a living medium, one where living creatures can process organic and mineral matter that make them available to plants. For example, some recent studies at Massey University have found that earthworms can release a large amount of potash from the clay minerals that are found in many soils. This may explain something that some Biodynamic growers have noticed - that available potassium levels in their soils have been increasing, even though they have not been applying any dressings with potassium in them.

So, what is it that Biodynamic growers do that conventional growers don't?

Preparing the compost

To start with, they adopt good organic practice. That means that they aim always to keep the amount of organic matter in the soil as high as possible. There are various ways of doing this. One is through compost making, which is relatively easy to do on a large scale -it's a matter of having the right machinery, management system and materials. While, to the conventional grower, these may appear quite difficult to organise, that's only because their use is not yet so widespread that they're taken for granted.

Another way of keeping up the levels of organic matter in the soil is through the use of green manure. The biodynamic grower generally hates to leave land bare -exposed to the sun and rain. Between crops he or she will grow green manure -perhaps a legume, such as clover, beans or vetch; mixed with a bulky plant such as oats. The plants are turned into the soil before they seed.

 

Green Manure

Nature herself is always willing to help in this process, and enthusiastically provides "green manure" plants without being asked. We generally call them weeds, and often set out to eliminate them. But weeds have their place, as long as it is not one that threatens the crop. In practice this means that the biodynamic grower has a more tolerant attitude to weeds - so long as the crop is not threatened, weeds can serve several valuable purposes. They can provide habitats for predators - such as hoverflies- that will help deal with insect pests. Typically, a biodynamically managed crop will contain a much greater range of weed species than a conventionally managed one, where there may be just a few weed types - perhaps those that are resistant to a specific herbicide. It is worth stressing, however, that tolerance to weeds extends only as far as the crop can allow - it doesn't mean that a crop can be allowed to become threatened by vigorous intruders in any way.

Biodynamic Preparations

To the biodynamic grower it's not enough to just increase the amount of organic matter in the soil, valuable as this is. It's also necessary to get the soil organisms working on it, to increase the life and vitality of the soil. For this, the biodynamic grower uses the biodynamic preparations - specifically the one known as "horn manure", or "500". Horn manure is made by putting cow manure in a cow's horn, and overwintering it below ground. That short sentence introduces a task that takes as much skill, organisation and good farming practice as any other part of agriculture. There are those who can do it well, and those who can't. When the horns are dug up in the spring, the cow dung has changed into a pleasant smelling, highly colloidal material - which has a slippery feeling when run through the fingers. Its respiration rate - the amount of oxygen it consumes can be very high, showing that it has a high level of biological activity. Other tests have shown that during the overwintering, the faecal bacteria are almost entirely replaced by humus forming bacteria.

Biodynamic Horn Manure

Biodynamic horn manure is applied to the farm or garden once, or preferably twice a year, at the rate of approximately one ounce stirred into three gallons of water per acre (60g/hectare in 34 litres of water). On small farms and gardens the work is easily done by hand, but on the thousand - acre hill country farm it is stirred by machine, and applied from the air.

After two or three applications over a period of eighteen months or so, the grower usually notices striking changes to the soil. They include a larger number of earthworms; deeper rooting of grasses; more numerous clover nodulations; improved crumb structure; and the worms active to a greater depth; bringing sub-soil up into the upper horizons. Eventually this may result in a greater depth of topsoil.

This process gives another clue to the general difference between biodynamics and the conventional way of growing things. The biodynamic grower, beginning with his use of the horn manure in very small quantities, comes to realise that small changes, if appropriately timed and managed, can have great effect. This is a bit like the chap on the rugby field who brings down the massive opposing player just when all looks lost. He knows that a little force, applied at the right time and in the right way will help the opponent on his way to where he wants him to go. The difference for the biodynamic grower, is that both the grower and Nature are on the same "side" - trying to get to the same point - healthy soil and healthy plants.

The biodynamic grower has a repertoire of other methods, similarly designed to support Nature without disrupting her. Biodynamic growers also use six different preparations - specially matured plant materials - to control the breakdown of their manures and composts. These also help make various trace elements more readily available to the plant. The biodynamic animal farmer also finds that homeopathy fits naturally into his way of thinking, but generally finds less need for animal remedies, as livestock are generally healthier. This was mentioned in a MAF report on organic farms, published in 1987, but which has never been followed up by more detailed studies until now. The Bio Dynamic Farming and Gardening Association is now awaiting the results of comparative studies on animal health it arranged with Massey University.

The Bio Dynamic Farming and Gardening Association is also the organisation that growers and farmers can turn to for advice about biodynamic methods. Much of its work is supporting growers in some way. It runs seminars and field-days to help people understand how to start applying biodynamic methods to their land. It offers a supportive network of other farmers and growers who have been down a similar road. It has advisors - practical farmers and growers - who will go to properties and give help on changing to biodynamic methods. It runs a small lending library, and can direct enquirer's to a wide range of books that can be purchased. It wrote a book called Biodynamics - New Directions for Farming and Gardening in New Zealand specially for New Zealand conditions. Although this has now sold out, it's still available in libraries. The Association offers regular publications - an annual biodynamic planting calendar, a resource directory and Harvests, a quarterly magazine circulated to members.