Humic acids

Humic acids or humus acids, are organic compounds formed during the natural decomposition and humification of organic material. They form an important part of the organic matter in soils and consist of various fractions, each with their own properties.

Within the group of humuszuren, a distinction is made between humic acids and fulvic acids. Together, they largely determine the biological and chemical activity of humus in soil and plants.

Humic acids and Fulvic acids

Humuszuren usually have a larger molecular weight and are mainly active in the soil. They contribute to soil structure, cation binding, and nutrient retention.

Fulvic acids consist of smaller molecules and are soluble across a wide pH range. This makes them more mobile in the soil and capable of transporting nutrients more efficiently toward the plant, and partially active through leaf uptake.

Role in soil structure and soil fertility

Humic acids play a central role in building and maintaining healthy soil structure. They promote the aggregation of soil particles, thereby improving air and water retention.

A good soil structure provides a better root environment, increases water-holding capacity, and makes the soil more resilient to drought or heavy rainfall.

Nutrient availability and chelating action

Thanks to their chemical structure, humic acids can bind nutrients and keep them in soluble form. This chelating action is especially relevant for trace elements such as iron, manganese, copper, and zinc.
This ensures nutrients remain more available to plants and limits leaching, contributing to more efficient fertilization.

Effect on soil life and microbial activity

Humuszuren serve as an energy and carbon source for microorganisms in the soil. An active soil life is essential for the breakdown of organic matter, mineralization of nutrients, and development of a stable soil structure.

By stimulating microbial activity, humuszuren can indirectly contribute to an improved nutrient cycle and long-term soil fertility.

Biostimulant effect on plants

Besides effects in the soil, humus- and fulvic acids can also directly influence the plant. They stimulate root growth, increase root branching, and improve the uptake and internal distribution of nutrients.

Furthermore, humuszuren can contribute to greater stress resistance in plants, such as during drought, salt stress, or temperature fluctuations.

Humic acids as a raw material for formulations

Humic acids are widely used as raw materials in liquid fertilizers, biostimulants, and soil improvers. Properties can vary greatly depending on the source and extraction method.

For producers, it is important to pay attention to parameters such as solubility, humic and fulvic fraction content, pH, color, and stability within formulations.

Application as a finished product

In addition to use as an ingredient, humuszuren can also be used as a standalone product, for example as a soil amendment to improve soil structure and soil life or as a supplement to regular fertilization programs.

Humic acids are used in both conventional and organic cultivation systems.