Humic and Fulvic acids

Humic and fulvic acids are complex mixtures of organic compounds that are formed through the breakdown of organic matter. Humic and fulvic acids can improve soil health and work as both soil improvers and growth stimulants. They can improve soil structure, enhance nutrient availability, stimulate microbial activity, and mitigate environmental stress.

What are Humic and Fulvic Acids?

Humic and fulvic acids are organic compounds that are produced by the breakdown of plant and animal matter in the soil. They are often referred to as humic substances, and are found in soil, sediment, and water. Humic acids are larger molecules that are less soluble in water, while fulvic acids are smaller molecules that are more soluble.

Humic and Fulvic acids in organic fertilizers

Organic fertilizers are derived from natural sources and contain essential nutrients for plant growth and improve soil health. By combining organic fertilizers with humic acids, you can enhance their overall effectiveness and provide additional benefits to the soil and plants. Here are some ways organic fertilizers enriched with humic acids can be beneficial:

  • Improved nutrient availability: Humic acids have a high cation exchange capacity (CEC), which allows them to attract and hold onto nutrients in the soil. When combined with organic fertilizers, humic acids can help retain and slowly release nutrients to plants over time, making them more available for uptake by plant roots. This can result in better nutrient utilization and reduced nutrient leaching.
  • Enhanced soil structure: Humic acids aid in soil aggregation, improving soil structure and porosity. When integrated with organic fertilizers, humic acids can help create a more stable and friable soil, which promotes better root penetration, aeration, and water infiltration.
  • Microbial stimulation: Organic fertilizers already contribute to the growth of beneficial soil microorganisms. The addition of humic acids can further stimulate microbial activity in the soil, leading to enhanced nutrient cycling and the production of plant growth-promoting substances.
  • Increased water holding capacity: Organic matter in the soil improves water retention, and humic acids are no exception. The combination of humic acids with organic fertilizers can further boost the soil’s water-holding capacity, reducing water stress for plants during dry periods.
  • pH buffering: Humic acids can help buffer soil pH, preventing rapid fluctuations. When incorporated into organic fertilizers, they contribute to maintaining a more stable pH environment, which is vital for optimal nutrient availability to plants.
  • Detoxification of pollutants: Humic acids can aid in detoxifying certain soil pollutants and chemical residues. When combined with organic fertilizers, they can contribute to the remediation of contaminated soils.
  • Sustainable soil management: By using organic fertilizers with added humic acids, farmers, landscapers and greenkeepers can adopt more sustainable soil management practices. The combination of organic materials and humic acids can improve soil fertility, reduce the need for synthetic fertilizers, and promote environmentally friendly agriculture.


MeMon can add humic and fulvic acids to fertilizers and soil improvers on demand. For solid fertilizers MeMon is using leonardite. Leonardite is a natural material derived from ancient, decayed plants. It is the richest natural material containing humic acids and fulvic acids. The quality of Leonardite can differ depending on the source of origin. MeMon is using high-quality leonardite with a humic acid content of more than 65% and a total carbon content around 50%.

Leonardite is allowed to be used in organic agriculture when obtained as a by-product of mining activities (EU 2021/1165). In the new EU fertilizer product regulation (EU 2019/1009) leonardite is also specifically mentioned to be allowed in organic and organo-mineral fertilizers and soil improvers.