What are Humic Substances and How Do They Help with Climate Control by Sequestering Carbon?


Humic Substances Properties


The America Society of Agronomy classifies the three components of HS s based on solubility. Fulvic acids (yellow) are very soluble in water, but brown humic acids (HAs) precipitate when acid is added to HA solutions. Humins (with a brown-black color) are insoluble in water and are believed to consist of humic acid molecules firmly attached to clay (such as kaolinite) or a mineral (such as hematite).

Humic acids (HAs) are the major fraction of humic substances. They contain more carbon than all living things. HAs exist in plants, soils, water, municipal solid waste, compost and sewage, and they can be isolated from soft coals. HAs strongly retain water and they are the buffer and matrix of many chemical and biochemical reactions in soils.