The relationship between soil microbiology and the biodynamic preparations

by Peter Proctor

How do the biodynamic preparations help the activity of soil?

Mycorrhizal fungi

There is a very interesting and easily read book for the layman on soil microbiology, which has been only recently published called “Tales from the Underground” by David W. Wolfe from Cornell University USA. It is published by Perseus Publishing Cambridge Massachusetts. Wolfe talks, among other things, a lot about soil bacteria and soil fungi and he describes the amazing connections between the bacterial and fungal life in the soil and plants. In particular the connections of the rhizobia bacteria (those are the bacteria that are responsible for the formation of nitrogen nodulation of the legume plants) and also the various mycorrhizal fungi which attach themselves to the roots of many plants in a symbiotic fashion. Mycorrhizal fungi form an association, with various plants, by means of their fine hyphae attaching themselves to the plant roots and seek out nutrients and moisture for the plant, in exchange for carbohydrates that the plant synthesizes by photosynthesis.

I have been looking at the nitrogen nodules on legumes resulting from nitrogen fixing bacteria, with the naked eye all my life and I am very familiar with the inoculation of various rhizobium species needed for different legumes. The rhizobia are host specific. Rhizobia needed for lucern are different from those needed for say soya bean, vetch or cow pea.

But of the mycorrhizal fungi I knew very little about except they existed on and grew around the roots of the pine trees, the silver birch and the oaks and aided their growth, but I had no idea that apparently 90% of all plants right through the world have a symbiotic relationship with the mycorrhizals. With an enlargement scope of 20X, these hyphae can be seen in and around the roots of the host plant and right through the particles of the surrounding soil. They are very fine and cobwebby looking, about 1 micron (finest merion or cashmere wool is 15-20 micron) and which penetrate the particles of soil. Not surprisingly they look like strands of fungus on mouldy bread. Incidentally these hyphae help bind the soil particles to form a crumb structure. Wolfe points out that the mycorrhizal fungi unlike the rhizobia bacteria are not always host specific and often spread from plant to plant and species to species. The strands of their hyphae are interconnected and apparently travel for very long distances seeking nutrients for the plants. Also often along with various helpful bacteria, plants are able to get their nutrition a long way from their root zone. A kind of food conveyor belt is in progress.

For instance, it is thus possible to have a symbiotic relationship between, the rhizobium bacteria which fix nitrogen from the atmosphere via the nodules on the roots of legumes, which are being grown between a crop of maize or sugar cane, and mycorrhizal fungi whose hyphae helpfully pass on the nitrogen from the legume to the roots of the crop. Apparently this is quite a comparatively recent discovery in research into the world of the mycorrhizal fungi and only since the last 10 to 15 years.

The Agriculture Course

Rudolf Steiner while giving the agricultural course in 1924 talked about the preparations for the first time and how they would enrich the manures and composts and also bring a sensitivity to the plant. When he had just finished talking about the dandelion preparation BD506, he said (in Chapter 5, page 104 Agricultural Course), “Now if you treat the soil as I have described, the plants will be able to draw on what they need from a very wide area. They will be able to use not only what is in their own field, but also what is in the soil of a nearby meadow if they need it or what is in the soil in a neighbouring forest.” He was obviously talking about the connecting hyphae of the mycorrhizal fungi.

So previously when I read this extract of Rudolf Steiner’s lecture, I had always found it difficult to understand. Now in relation to Wolfe’s explanation of the activity of the hyphae and the distances they could travel to collect nutrients and moisture, it all suddenly made sense! We are using the preparations, in one way to encourage this microbial soil life and the resultant balanced soil which supports healthy plants. Thus one function of the preparations is to improve the effectiveness of these soil mycorrhizae. And another function is that the healthy living soil allow the cosmic growth forces to stream into the soil to support plants of healthy and nutritious quality.

Research Work

There has been some work done recently by Prof. Barbara von Wechmar, a microbiologist at the Stellenbosch University in Capetown, So. Africa, of growing fungi and bacteria samples from the BD preparations and CPP in the laboratory on various substrates. These all showed a tremendous variety of fungi and bacteria. The BD500 picture was described by Prof. Barbara as an interesting and beautifully balanced collection of fungi.

Dr. Perumal from the MCRC Institute in Chennai, Tamil Nadu, India has tested the BD preparations for bacteria and particularly rhizobia. He found the BD500 cow horn dung and the BD504 Stinging Nettle have remarkably high numbers of this bacteria.

Work done at ICRISAT in Hyderabad, Andhra Pradesh, India has found beneficial bacteria, antagonistic towards Fusarium root fungus of chick peas, in compost treated with biodynamic preparations, which effectively combated the fungus.

This shows the benefits of the beneficial bacteria in the BD preps and which can be multiplied during the composting process.

The Preparations

The Biodynamic preparations, when applied to the soil in the various ways – through the stirred cow horn dung BD500, and the preparations BD502-507 which are used in composts, liquid manures or cow pat pit (CPP) – on one level actually work through the soil micro life and encourage the development of mycorrhizal fungi hyphae and the rhizobia as well as other micro and macaro soil organisms. They thus work to enliven the soil structure and make the plant nutrients more available. Again to quote Rudolf Steiner, “The plants then will be able to use not only what is in their own field, but what is in the soil of a nearby meadow if they happen to need it or of what is in the soil in the neighbouring forest.” The forces that are in the preparations work through the microbial life in the soil or the healthy nature of the soil. Cosmic influences come into the soil through healthy living soil.

Actually the preparations make the organic part of the soil active and living. The biodynamic farmer can actually see the changes in the structure of his soil and also most importantly the health and quality of his crops.

The enlivening of the soil through the increase of the living organisms therein, is the most important aspect of the biodynamic system of agriculture. Actually it is the preparations which make organic farming work.

We can now come to the thought that there is a spiritual impulse or connection, working out there between the soil, plant and the cosmos. The preparations when used on the land, can be seen as a bridge between the life of the soil and the wholesome growth of all plants. Rudolf Steiner talks about nature spirits or elemental beings which are also a bridge between the world of spirit and the world of plant and the world of animals. Thus, it is great if the farmer can develop a connection with his plants and his animals with enthusiasm for their well-being.

Rudolf Steiner calls it the etheric formative force, where Spirit is working out of Matter.