What are Biostimulants?
The first theoretical approach to biostimulants began as early as 1933 in the USSR with research by the Russian physician V.P. Filatov. He observed that diseased and stressed organisms stimulated regeneration and suppressed pathological processes through treatment with biological material from animal and plant components. As early as the 1950s, it was also proven that biostimulants promote plant growth, improve nutrient efficiency and increase water uptake. Today, biostimulants are defined by the EU as "substances or materials (excluding nutrients and pesticides) which, when applied to the plant, seed or growing medium in specific formulations, alter the physiological processes of plants by improving growth, development and/or increasing tolerance to abiotic stress".
Biostimulants based on water-soluble concentrated humic acid extracts of leonardite and aquatic fulvic acids are already used worldwide as biostimulants in adverse climatic and soil conditions for the purpose of climate-adapted agriculture. Climate-related abiotic stress factors include heat, drought and salt stress, but also wetness, frost and cold. Humic-based biostimulants such as humic and fulvic acids serve to increase the tolerance of crops to these abiotic stress factors. For example, humic and fulvic acids are able to decisively reduce the salt concentrations in the soil solution through their adsorption capacity and thus enable higher-yielding agriculture again via the lower salt-induced osmotic pressure on the plants.
At the same time, humic and fulvic acid-based biostimulants increase the fertilisation efficiency of macronutrients such as phosphorus, nitrogen and potassium. Especially for the plant-available mobilisation of mineral fixed phosphates, humic substances play a decisive role in the soil. In addition, humic substances mobilise essential trace nutrients such as iron, zinc, copper and manganese, which otherwise cannot be directly absorbed by crops, especially in dry soils poor in humus.
The complexation of these trace nutrients by natural humic acids is an excellent alternative to persistent synthetic chelates such as EDTA. The adsorption of ammonium nitrogen by humic substances reduces emissions of the greenhouse gas ammonia from farm manures such as slurry and digestate, while at the same time helping to reduce nitrification and thus nitrate inputs into groundwater. Leonardite-based humic substances thus make a decisive contribution to the implementation of the European Green Deal and the agricultural strategy "From Farm to Fork".