| Themes > Science > Earth Sciences > Geology > Soils > Soil Composition > Components and Structure > The Soil Community |
The living part of the soil is just as critical to Plant growth as the physical soil structures. Soil microorganisms are the essential link between mineral reserves and plant growth. The cycles that pen nit nutrients to flow from soil to plant are all interdependently and they work only with the help of the living organisms that constitute the soil community. Soil organisms, from bacteria and fungi to protozoans and nematodes, on up to mites, springtails and earthworms, perform a vast array of fertility-maintenance tasks. Organic soil management aims at helping soil organisms maintain fertility; conventional (non-organic) soil management merely substitutes a simplified chemical system to provide nutrients to plants. Once a healthy soil ecosystem is disrupted by the excessive use of soluble synthetic fertilizers, restoring it can be a long and Costly process. In many cases, the excessive use of energy-intensive petroleum-based fertilizers and pesticides has destroyed the biological fertility of soil, so growers use ever-larger amounts of these materials to sustain crop growth. Like all living things, the creatures of the soil community need food, water, and air to carry on their activities A basic diet of plenty of organic material, enough moisture, and well-aerated soil will keep their populations thriving. Soil creatures thrive on raw organic matter with a balanced ratio of carbon to nitrogen, about 25 to 30 parts carbon to 1 part nitrogen. Carbon, m the form of carbohydrates, is the main course for soil organisms. Given lots of it, they grow quickly scavenging every scrap of nitrogen from the soil system to go with it. That's why adding lots of high-carbon materials to your soil can cause nitrogen deficiencies in plants. In the long term, carbon is the ultimate fuel for all soil biological activity and therefore of humus formation and productivity. A balance supply of mineral nutrients is also essential for soil organisms, and micronutrients are important to the many bacterial enzymes involved in their biochemical transformations. |
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