What is Organic Matter Made Of?
Organic matter is primarily composed of the remains and waste products of living organisms. This includes both plant and animal material.
Organic matter is a complex mixture, but its main constituents include:
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Plant Residues: These are the leftover parts of plants after they die, such as leaves, stems, roots, and fruits. These residues are rich in cellulose, lignin, tannins, and other complex carbohydrates. [Source: Wikipedia, SARE, Agriculture Victoria]
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Animal Residues: This encompasses the waste (feces) and remains of animals, both large and small, including insects and microorganisms. [Source: Wikipedia, Quora]
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Microorganisms: A significant portion of organic matter consists of living and decaying microorganisms like bacteria, fungi, algae, and protozoa. These organisms play a crucial role in the decomposition process. [Source: SARE, Quora, UVM]
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Humic Substances: These are complex, dark-colored organic molecules formed during the decomposition of plant and animal matter. They are vital for soil health. [Source: Wikipedia]
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Other Organic Compounds: Proteins, lipids (fats), and sugars are also present in varying amounts depending on the source of the organic matter. [Source: Agriculture Victoria]
Aboveground vs. Belowground Organic Matter
The composition of organic matter can vary depending on its location:
- Aboveground: Primarily plant and animal residues.
- Belowground (Soil): Includes living soil organisms (fauna and microflora), partially decomposed plant and animal residues, and humic substances. [Source: Wikipedia]
Examples of Organic Matter Sources
- Agricultural fields: Crop residues, animal manure, compost.
- Forests: Leaf litter, decaying wood, animal carcasses.
- Aquatic environments: Dead algae, decaying plants, and animal remains. [Source: USGS]
- Glaciers: Surprisingly, glaciers also contain organic matter, the composition of which varies depending on the glacier's location and surrounding environment. [Source: EOS]
The percentage of organic matter in soil is a key indicator of soil health and fertility, with most productive agricultural soils containing between 3 and 6% organic matter. [Source: Cornell] Most soil organic matter originates from plant tissues, which are composed largely of carbon, oxygen, and hydrogen. [Source: FAO]
