Humic and fulvic acids play an important and vital role in maintaining soil fertility, nutrition and plant growth. Crops grown in soils that contain a sufficient amounts of humic (HAs) and fulvic additives (FAs) have increased resistance to abiotic stress, are healthier and ensure higher yields. In addition, the nutritional value and quality characteristics of harvested products are significantly enhanced. The contribution of humic and fulvic additives to soil fertility and plant nutrition is related to the various functions that these complex organic compounds exert on our planet, as a basic and integral part of the life cycle.

According to several reports, humic and fulvic acids are widely recognised by the scientific community as the most important feature of a healthy and fertile soil. With a better understanding of how these carbon-based substances work, it is possible to design both products and nutritional solutions for more sustainable and rational farming.

What are humic and fulvic acids?

Humic acids (HAs) include a mixture of weak aliphatic and aromatic carboxylic acids, which is poorly soluble in water under acidic conditions, but readily soluble under alkaline conditions.

Fulvic acids (FAs) are a mixture of weak aliphatic and aromatic carboxylic acids, which is readily soluble in water under all pH conditions. Their composition and structure are quite variable.

Fulvic acids (HFs) are smaller in size than humic additives (HAs), with molecular weights ranging from about 1,000 to 10,000. Fulvic acids (FAs) have twice the oxygen content of humic acids (HAs). They have many carboxyl (COOH^–) and hydroxyl (COH^–) groups, thus fulvic acids (FAs) are much more chemically reactive. The exchange capacity of fulvic acids (FAs) is more than twice that of humic acids (HAs). This high exchange capacity is due to the total number of carboxylic (COOH^–) groups present.

Due to the relatively small size of fulvic acid (FA) molecules, they can easily enter the plant both through the root system and foliage. As they enter these plant parts, they carry trace elements from the foliage surfaces into the plant tissues. For these reasons, fulvic acids (FAs) are marketed as essential components of high-quality foliar crop nutrition products.

However, the greatest contribution of humic and fulvic acids is related to their effect on soil. It has been calculated that the addition of the above humic compounds to the soil solution improves the following:

• Cation exchange capacity (CEC). The carboxyl groups size of humic and fulvic acids, which are added, leads to negatively charged nutrient-attracting valences.
• Soil structure. Humic and fulvic acids contribute to the increase of macropores, which leads to better ventilation and drainage conditions for the soil. At the same time, the combined presence of micropores ensures the ideal retention of water and nutrients.
• Release of radicals and growth enhancement of the aerial part of the plant.
• Biological properties of soil. As a source of carbon, humic and fulvic acids enhance the development of the network of beneficial – symbiotic soil microorganisms (mycorrhiza).
• Availability of phosphorus. The availability of phosphorus is increased as a result of the adsorption of humic compounds on the surfaces of aluminium and iron oxides.
• Urea efficacy. The addition of humic compounds from leonardite has been estimated to reduce the loss of ammonia gas.
• Root cell elongation.
• Availability of iron and zinc nutrients.

At Phytothreptiki, innovation is a key feature of our company identity. We are constantly developing and enriching an extensive list of organic crop nutrition products, using high-quality humic and organic matter.