Monday, September 21, 2015

Healthy Soils

Healthy soils are full of life. This life is comprised of literally millions of different species and billions of individual organisms both large and microscopic. Forty million bacteria can fit on the end of one pin. Other microbes include algae, protozoa, yeasts, fungi and nematodes. Some of these organisms feed on dead organic matter, while others feed on other microorganisms. As a group, they help to recycle nutrients, build the soil structure and most important, help to convert organic matter into rich, stable humus. It is the humus which is the life support system of the soil.

The following soil problems can be corrected by adding humus:

1. compacted soils,
2. fluctuating pH levels,
3. infertile soils,
4. sandy soils 
5. clay soils and
6. in addition, a soil rich in humus will help reduce pest insects and disease pathogens in the soil.

How do soil organisms build better soil? 
Bacteria – feed on organic matter, store and cycle nitrogen and decompose pesticides.

Fungi – some feed on dead organic matter like crop residues; others are parasites that attack other microbes. Some live in association with plant roots delivering nutrients to the plant.

Protozoa – eat bacteria, fungi and algae. The consumption of bacteria slowly releases nitrogen into the soil. Protozoa also convert organic nitrogen, not available to plants, to nitrogen forms which are available.

Mites – decompose organic matter.

Nematodes – these microscopic worms eat other worms in the soil and are an important part of the nitrogen cycle. Some nematodes attack plant roots but most are non-pathogenic.

Earthworms – expel partially decomposed organic matter which produces  nutrient rich casts. In addition, the worms create some small tunnels which aid in the development of good soil structure and water movement in the soil.