Let’s take a look at the types of humic acid.
Humic acid primarily includes three types: black humic acid, brown humic acid, and red humic acid.
I. Black Humic Acid
Black humic acid refers to humic substances composed of organic matter such as humic acid and fumaric acid, which have relatively high molecular weights. Its color is generally dark brown to black, hence the name. Besides being found in soil, black humic acid is also widely present in the decomposition products of biomass such as peat.
Black humic acid has high stability and inertness, thus having a significant impact on the environment. For example, it can adsorb and detoxify heavy metal ions in the soil, promote root absorption of water and nutrients, and increase soil aeration and water retention capacity.
II. Brown Humic Acid
Brown humic acid refers to organic matter with smaller molecular weights, composed of organic matter such as oligosaccharides, proteins, and nucleic acids. Its color is dark brown to reddish-brown. Brown humic acid is one of the most abundant organic substances in soil and can be found in various types of soil.
Brown humic acid possesses high biological activity. It can promote plant growth, regulate soil temperature and humidity, increase soil aeration and fertility, and improve soil structure.
III. Red Humic Acid
Red humic acid refers to organic matter containing more sugars and nitrogen, and its color is generally reddish to brownish-red. It is present in lower concentrations in soils and is generally distributed in tropical and subtropical climates.
Red humic acid possesses certain biological activity. It can promote the development of soil microbial communities, improve soil physical and chemical properties, and increase soil fertility.
Therefore, it is easy to see from the above that humic acid mainly includes three types: black humic acid, brown humic acid, and red humic acid. Each type of humic acid has its unique properties and functions, playing different roles in different soil environments.
