A healthy soil is one where there is life! — earth worms, insects,
bacteria, fungi, protozoa and nematodes. It is not just the balance of
nitrogen, phosphorus and potassium. One teaspoon of a healthy soil may
contain in 1 teaspoon millions of beneficial soil microorganisms
including 25,000 species of bacteria, 10,000 species of fungi which with
other soil microbes decompose organic matter, promote deep root
development, improve soil permeability and provide plants with
nutrition, moisture and resistance to pests. Plants thrive or suffer
depending on the life in the soil. Beneficial soil organisms make
nutrients available to plants, reduce disease, reduce nutrient losses
and help degrade toxic chemicals. You can't see much but you can smell
and feel the texture. Biological inputs must be chosen carefully to feed
the myriad of soil life. Bacteria feed on plant residue and root
exudates converting these compounds into body mass, this becomes food
for the next level of the food web. Protozoa that feed on these bacteria
excrete nitrogen as a waste product that then provides nutrients
essential to plants. 85% of all plant nutrients must be first cycled
through micro-organisms. Farming disrupts this process. We are gradually
mining the soil of organic matter that is the protoplasmic basis for
life on earth.. So that nutrients are cycled, disease is suppressed and
nitrogen is retained so there is no leaching. If you re-establish
healthy micro-organisms in the soil farm productivity goes up and costs
are cut by eliminating pesticides and chemical fertilisers.
/*"Every chemical-based pesticide, fumigant, herbicide and fertiliser
tested, harms or outright kills some part of the beneficial life that
exists in the soil, (or on the leaf surfaces) even when applied at rates
recommended by their manufacturers. ..( L)ess than half of the existing
active ingredients used as pesticides have been tested for their effects
on soil organisms."* /
There are others looking at pertinent issues like peak Phosphorus and
Nitrogen usage.
The reports are not very searchable at the moment - the new Nuffield UK
Director is interested in any feedback on improving this that users can
offer. The downloads are free to access, a fee is payable for hard copies.
Hope you find them worthwhile!
Susi Batstone
[permaculture] What is healthy soil. (FWD thread from other list),
Lawrence F. London, Jr., 07/06/2013