New Mexico Chile Task Force

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Soils: Organic Matter

Consist of plant and animal residue in various stages of decomposition, living soil organisms and substances synthesized by these organisms. Amount of organic matter that may accumulate in a soil from plant tissue depends upon the temperature, moisture, aeration, soil pH, microbial population, and the quantity and chemical nature of the plant residue returned to the soil.

Principal Benefits of Soil Organic Matter

  1. Helps build stable soil aggregates, thus improving soil structure and tilth.
  2. Improves aeration and water penetration.
  3. Improves moisture-holding capacity.
  4. Provides an abundance of negatively charged colloidal particles (humus) capable of holding and exchanging nutritive cations.
  5. Acts as a buffering agent by decreasing the tendency for an abrupt pH change in the soil when acid-or-alkaline-forming substances are added.
  6. Affects the formation of metal-organic complexes, thus stabilizing soil micronutrients that otherwise might not be available.
  7. Provides a source of many plant nutrients.