Soil Health

Regenerating soils is one of the most important values in Biodynamic agriculture. It is the basis for the best outcomes for our food, our heath, and that of the planet Earth.


Humus is the dark organic matter that forms in the soil when plant and animal matter decays.  Humusis the foundation of living soil.

Importance of Humus for Soil Structure & Fertility in Soils

  • Soils that have a high humus content, have an abundant living biological activity to convert plant residues, leaf litter, animal dung and various biomass into stable humus.
  • Humus gives the soil the ability to absorb and retain moisture. They do not dry out and require significantly less irrigation.
  • Humus provides a reservoir for the plant nutrients available in the soil for balanced plant growth.
  • Humus plays a part in supporting soil bacteria, such as rhizobacteria so important for all legume nodulation and other well-known bacteria, such as the phosphate solubilizing bacteria.
  • An exudate from bacterial activity results in polysaccharides (a sticky substance) being released, which helps bind the small soil particles into a nutty crumb structure to a depth of 30cm or more.
  • Humus also supports the all-important mycorrhizal fungi, which form a symbiosis with many plants and are an important factor in the soil food web. The hyphae from these fungi help bind the soil particles to form a good soil structure.

Bio-dynamic Farming & Humus

An essential part of the art of farming is the observation of soil quality. When the biodynamic activity is working well in the soil of the farm, soils of all types have a common look to them. They have a crumbly, nut structure, and the humus content gives a slippery feel when rubbed between finger and thumb. A coarse feel indicates a lack of humus. By running your finger down the length of the profile you can determine the depth to which the humus is in the soil.

On a biodynamic farm, as the years’ progress, you will find that the soil has this slippery feel to lower and lower depths. The roots also penetrate deeper and deeper. Earthworm castings are found deeper too — down to where the subsoil and topsoil meet. The earthworms work to mix the subsoil and topsoil where they adjoin, increasing the depth of the living topsoil layer each year.

It is important to observe the degree of mixing of earthworm castings between the subsoil and the topsoil. A good soil on a dairy farm after a few years of Preparation 500 can have over 100 earthworms in a cubic foot.

A good fertile living soil will have a strong microbiological life where azobacter and rhizobacter support healthy nodulation on all legume plants, especially where Preparation 500 is being used.
Abstracted from ‘Grasp the Nettle’ by Peter Proctor

Root Nodulations Comparision

A good biodynamic soil allows roots to penetrate widely, so that they are not cramped and all the root hairs have plenty of room. Observe also that the soil clings persistently to the root hairs. This does not happen in a non-biodynamic soil. In a soil that has been treated with water-soluble fertilisers the roots are contracted and turned in.

In trials conducted at the Agricultural College of Indore comparing the effect of biodynamic preparations with that of conventional fertiliser application, there were dramatic contrasts in root development in the different plots. The biodynamic plot showed root development deep into the soil, whereas in chemically treated plots the roots were mainly near the surface.

Researchers at Massey University in New Zealand made several standard soil-quality measurements on soil from several pairs of neighbouring biodynamic and conventional farms. They found that :

the biodynamic soils were generally significantly superior to conventionally managed soils in regard to soil structure, friability, aeration and drainage, lower bulk density, higher organic matter content, soil respiration, and mineralisable nitrogen, more earthworms and a deeper topsoil layer.

Comparision of Root Development

Nodulation on a BD managed plot

Soil from a BD managed plot

Soil from a chemically treated plot

Vitality and Quality of Soil

The vitality and quality of soil can be improved by regular application of:

  • compost made with Preparations 502-507
  • liquid manures made with Preparations 502-507
  • cowpat pit manure made with Preparations 502-507

and in addition by:

  • turning in plant material such as green crops and straw
  • not using chemical fertilisers and pesticides
  • avoiding soil compaction by machinery or animals, particularly in wet weather
  • keeping soil covered by pasture, crops or mulch
  • not destroying the soil structure by poor farming practices such as excessive use of the rotary hoe or cultivation in unsuitable weather (too wet or too dry)
  • following the land by planting deep-rooting permanent pasture species or using green crops.