Functions of Soil Organisms
Giving Life to Your Soils

Custom Search

There are millions of organisms in a fistful of soil and these soil organisms, many of them microorganisms too small to see with the naked eye, feast on organic matter like grass clippings, plant leaves and algae. They reduce the dead organic matter on the Earth's surface and discharge nutrients from the decaying organic matter for living plants to utilize.

• plants, algae and bacteria that photosynthesizes
  major function= seize energy
  1. employ solar energy to fix CO₂
  2. furnish organic matter to soil-biomass like dead cells, plant litter and secondary substance involved in metabolism.

• bacteria and fungi that decomposes
  major role= break down matter that remains after something has been removed
  1. block, hold back, nutrients in their plant materials and animal waste used as fuel
  2. produce new organic compounds that are origins of energy and foods for other organisms.
  3. make compounds that help attach soil into aggregates.
  4. attach soil aggregates with fungal hyphae.
  5. nitrifying and denitrifying bacteria change kinds of nitrogen.
  6. contend with or suppress disease-causing organisms.

• bacteria and fungi that mutate
  major role=discourage disease
  1. guard plant roots from disease-causing organisms.
  2. many bacteria stabilize nitrogen.
  3. many fungi build mycorrhizal associations with roots and process nutrients such as potassium and water to the plant.

• bacteria and fungi are pathogens
  
• nematodes, microarthropods parasites
  major role=encourage disease
  1. devour roots and other plant portions, causing disease.
  2. parasitize nematodes or insects, including disease-causing organisms.

• nematodes, macroarthropods like cutworm, weevil larvae and symphylans are root-feeders major role=devour plant roots
  1. possibly cause substantial crop yield losses.
  

• protozoa and nematodes are bacterial-feeders
  major role=superficial abrasion
  1. discharge plant available nitrogen and other nutrients when feasting on bacteria.
  2. contain most root-feeding or disease-causing varmits
  3. energize and control the action of bacterial masses
  

• nematodes and microarthropods are fungal-feeders
  major role= graze
  1. free plant available nitrogen and other nutrients if feeding on fungi.
  2. curb many root-feeding or disease-causing pests.
  3. stimulate and restraint the activity of fungal populations.

• earthworms and macroarthropods are shredders
  major role=decompose residue and heighten soil structure.
  1. tear up plant litter as they consume bacteria and fungi.
  2. furnish habitat for bacteria in their intestines and fecal spheres.
  3. improve soil structture as they make fecal pellets and tunnel through soil.

• nematode-feeding nematodes, larger arthropods like mice, voles, shrews, birds, and other above-ground animals are higher level predators.
  major role= contain masses
  1. control the many lower trophic-level predators.
  2. bigger organisms help soil structure by tunneling and by passing soil through their intestines.
  3. larger organisms transport smaller organisms over long lengths.