humic acid

noun

1. a brown, melanin-tinted mixture of polymers, found in lignite, peat, and soils, where it acts as a cation exchange agent: used in drilling fluids and inks.

Word History and Origins

Origin of humic acid¹

First recorded in 1835–45

Example Sentences

The decaying mosses release humic acids and sphagnan, a complex sugar, that make life difficult for the microorganisms that would normally cause rotting and decay.

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All of it has darkened somewhat because of the development of humic acids.

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Organic-rich soils seem particularly problematic; they are ripe with molecules like humic acid, which behaves like DNA and can foul later sequencing.

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When a plant dies, decay brings organic material, a component of which is large carbon-based molecules called humic acids, into the soil and binds them to the soil’s molecules.

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This is made by aerating sugars, compost and humic acids in non-chlorinated water and then spraying the brew on plants and soil.

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