Soil Conditioners
Black Treasure, Leonardite
Soil conditioners are natural or organic materials used to promote plant growth and improve the physical and chemical structure of the soil. Research on materials such as vermicompost, biochar, humic acid derivatives, and leonardite shows that the use of these additives increases the soil's water-holding capacity, helping to retain moisture in the root zone. These products also support microbial activity, restoring soil vitality.
In 2023, Saliha Dorak at Bursa Uludağ University published her doctoral thesis, "Comparison of the Effectiveness of Biochar, Vermicompost, and Leonardite Applications in Saline and Calcareous Soils," which examined the effects of organic and natural conditioners on plant nutrition and productivity in challenging soil conditions, making a significant contribution to the literature.
This study comparatively investigated the effects of different organic soil conditioners (vermicompost, biochar, and leonardite) on saline and calcareous soils. According to the study, vermicompost supports root development by increasing organic matter and microbial vitality; leonardite improves ion exchange and water retention capacity thanks to its humic and fulvic acid content; and biochar significantly increases plant yield, particularly in calcareous soils, by improving the availability of nutrients. The research results show that when these three conditioners are used together, they restore soil vitality and offer a strong alternative for sustainable agriculture by reducing dependence on synthetic fertilizers.
Leonardite is a natural organic material formed by the oxidation of lignite coal, containing high levels of humic and fulvic acids. It contains carbon, oxygen, hydrogen, nitrogen, and sulfur. Its working principle is based on these acids increasing the soil's ion exchange capacity, allowing plant roots to absorb nutrients more easily. It also regulates the soil's pH balance, increases its water-holding capacity, and reduces heavy metal toxicity. A simple visual illustration of this mechanism is provided below.
Sources;
Dorak & Gazi University (2021) – Technological Investigation of the Usability of Leonardite in Agriculture in Türkiye
MTA Energy Raw Materials Survey Department (Şengüler, 2012) – Leonardite: Properties, Importance and Economic Value
Turkey possesses rich deposits of Leonardite. High-quality Leonardite reserves are particularly found in the Afşin-Elbistan, Soma, and Tunçbilek regions. These resources offer an economical and domestic alternative for use in both agricultural and environmental projects. While the benefits of Leonardite use have been known for the last decade, it is not yet being utilized to its full potential.
Investors are being sought to utilize the approximately 2 billion tons of leonardite reserves located at the Elbistan thermal power plant in various sectors such as agriculture, livestock farming, cosmetics, and pharmaceuticals, thereby contributing to the national economy.
Source: Analiz Newspaper. Read the full text.
Leonardite is generally applied in granular, powder, or liquid form. In field conditions, it can be mixed directly into the soil or added to irrigation water. The application rate varies depending on soil analysis, but is generally between 2–5 kg/da. Application close to the plant root zone maximizes the effect of humic acids.
Our leonardite application at our project site.
Information brochure we prepared for our project stakeholders.