HUMUS - the foundation of LIVING SOIL                                         

HUMUS - the organic constituent of soil,
usually formed by the decomposition of plants and leaves
[Latin, literally 'soil'] Oxford Dictionary

Organic farming has as its main basis, the health of the soil. Before the advent of modern agricultural techniques at about the beginning of the 20th century, all soils right across the world were healthy and living. This fertility being the result of thousands of years of careful husbandry where all the plant residues and all the cow and other domestic animal manures were returned to the soil. A wonderful soil microbial life had been built up over these years. This has been documented in many articles on soil written over the centuries.

Modern agricultural science holds the belief that to feed a hungry world and meet the demand for an increase in food supply artificial forms of nitrogen, phosphorous, potash and all micronutrients must be added as some form of chemical salt to grow food. Acid based chemical fertilisers kill off the various soil bacteria, beneficial fungus and earthworms, which support the all important humus, which is the great basis of soil structure. So the soil lost its natural fertility.

Plants now weakened by being fed with artificial fertilisers have developed all kinds of fungus diseases and susceptibility to many insect attacks, and as a consequence a whole regime of chemical plant pesticides and fungicides are now also being used. These chemicals are causing poisonous pollution of the soil, the water and of humans. The end result is that hectares and hectares of farming soils the world over have lost their structure, and are now degraded soils.

Importance of Humus for Soil Structure & Fertility in Soils
  Soils that have a high humus content, have abundant living biological activity to     convert plant residues, leaf litter, animal dung and vaious biomass into stable     humus.

It is said that the weight of the organisms in the soil, equals the weight of the animals above the ground that that soil can support. The micro organisms are bacteria, including rhizobia (nitrogen fixing), phosphate solubilizing bacteria, mycorrhizal fungi, algi, actinomycetes and protozoa. Then there are the macro organisms, such as nematodes, springtails, mites, ants, millipedes and earthworms.

 Humus gives the soil the ability to absorb and retain moisture. Such soils 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 rhizobacta 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 mycorryhzal 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 good soil     structure.

Bio-dynamic Farming & Humus
Abstracted from Grasp the Nettle by Peter Proctor

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.

Nodulation on a BD managed plot


Nodulation on a chemically treated plot

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.

There is a farm in Gujarat, which has been using all the biodynamic preparations for the last four years. The farmer has been using Preparation 500 and CPP (cowpat pit) since 2001, four times in a year. The ploughman who has been ploughing on this land with a bullock-drawn single-furrow plough for the last twenty years said to the farmer, 'Sahib, what have you done to the soil to make it so soft? It is like ploughing cotton and my feet no longer get sore!' Such anecdotal stories are backed up research.

Researchers at Massey University in New Zealand made several standard soil-quality measurements on soil from several pairs of neighbouring biodynamic and conventional farms. (Reganold et al, 1993). 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.

Soil from a BD managed plot


Soil from a chemically treated plot

The vitality and quality of soil can be improved by regular application of:
Preparation 500
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)
fallowing the land by planting deep-rooting permanent pasture species or   using green crops.