Humus Chemistry: Genesis, Composition, Reactions
Key Findings
- Definitive textbook on humic substance chemistry — humic acids, fulvic acids, humin
- Covers extraction methods, structural models, metal complexation, and biological activity
- Standard reference for humic substance composition and properties
The standard scientific reference for humic substance chemistry, cited across soil science, environmental chemistry, geochemistry, and balneology. Frank J. Stevenson’s textbook, now in its second edition (Wiley, 1994), is the work researchers cite when they need to establish what humic acids, fulvic acids, and humin actually are and how they behave chemically.
What It Covers
The book addresses the full lifecycle and chemistry of humic substances: how they form through humification (the decomposition and transformation of organic matter), their molecular composition and structural models, how they interact with metal ions, mineral surfaces, and water, and their biological activity. The treatment is comprehensive and referenced — this is not a popular science text but a technical reference for chemists and soil scientists.
Why It Appears in Peat Therapy Literature
Balneology papers frequently cite Stevenson for two purposes: establishing the basic chemistry of the humic substance fractions (what distinguishes fulvic acids from humic acids, what humin is, how molecular weight relates to pH solubility) and for the metal complexation data (the chelating capacity of humic substances, relevant to peat’s detoxifying and mineral-delivery claims). When peat therapy papers say fulvic acid is “soluble at all pH values” or describe the solubility fractionation of humic substances, Stevenson is the reference behind those statements.
Grade Note
The Grade A here reflects the quality and authority of the source, not a clinical evidence grade. This is not a clinical trial — it is the foundational chemistry reference that underpins the molecular claims made throughout the peat therapy literature.
Where this source is used on this site
Each page below cites this paper as evidence for a specific claim. The note shows what the page draws from it.
FA soluble at all pH values — remains bioavailable in bath water
FA soluble at all pH values — remains bioavailable in aqueous solutions
Chapter 9 — fulvic acid metal binding constants
Chapter 9 — metal-humic complexation
Physical properties of humic fractions
Organic acid contribution to soil/peat acidity — dissociation of carboxyl groups
Chapter 2 — humic substance content of organic soils
Chapter 2 — fulvic/humic ratio varies by peat type
Chapter on organic matter composition — tannins classified as polyphenolic compounds
Chapter 9: humic substance metal-binding constants — chelation of Fe²⁺, Cu²⁺ pro-oxidant ions