What are Humic Acids?

1. Humic matter 

Humic matter is formed through the chemical and biological humification of plant and animal matter (pic.1.1) and through the biological activities of microorganisms.

Picture 1.1 — Typical vegetation of the Tertiary period.

The best source of humic acids are the sedimentation layers of soft brown coal, which are referred to as Leonardite. (pic.1.2, pic.1.2a, pic.1.3) Humic acids are found in high concentration here.
 

Leonardite acts as a conditioner for the soil and as a biocatalyst and biostimulant for the plant (pic. 1.10). Compared to other organic products, Leonardite enhances particularly plant growth (biomass production) and fertility of the soil.

Another advantage of Leonardite is its long-term effectiveness, as it is consumed as quickly as animal manure, compost or peat. As Leonardite is a degradation product, it does not compete with plants for nutrients such as nitrogen. This is not the case with incompletely decomposed compost, whereby the organic substances in soil are rapidly consumed up by micro organisms and mineralize without any humus formation.

Our Leonardite-based products improve the soil structure for up to five years.

Picture 1.10 — Development of root system of Tomato plant with LIQHUMUS® (right) and with water only (left). (Copyright © Humintech 2018)

2. BENEFITS OF HUMIC ACIDS

Current scientific studies show that the fertility of soil is determined to a very large extent by the content of humic acids. Their high cation-exchange capacity (CEC), the oxygen content as well as the above average water holding capacity are the reasons for the high value of using humic acids for improving soil fertility and plant growth.
The most important feature of humic acids is their ability to bind insoluble metal ions, oxides and hydroxides, and to release them slowly and continually to plants when required. Due to these properties, humic acids are known to produce three types of effects: physical, chemical and biological.

2.1. Physical Benefits:

Humic acids physically modify the structure of the soil. They

• improve the structure of soil: Prevent high water and nutrient losses in light, sandy soils. Simultaneously convert them into fruitful soils by way of decomposition. In heavy and compact soils, aeration of soil and water retention are improved; cultivation measures are facilitated. 
• prevent soil cracking, surface water runoff and soil erosion by increasing the ability of colloids to combine.
• help the soil to loosen and crumble and thus increase aeration of soil as well as soil workability.
• increase water holding capacity of soil and thus help resist drought.
• darken the color of the soil and thus help absorption of the sun energy.

2.2. Chemical Benefits:

Humic acids chemically change the fxation properties of the soil. They

• neutralize both acid and alkaline soils; regulate the pH-value of soils.
• improve and optimize the uptake of nutrients and water by plants. 
• increase buffering properties of soil.
• act as natural chelator for metal ions under alkaline conditions and promote their uptake by the roots.
• rich in both organic and mineral substances essential to plant growth.
• retain water soluble inorganic fertilizers in the root zones and reduce their leaching.
• possess extremely high cation-exchange capacities.
• promote the conversion of nutrient elements (N, P, K + Fe, Zn and other trace elements)
  into forms available to plants.
• enhance the uptake of nitrogen by plants.
• reduce the reaction of phosphorus with (Ca, Fe, Mg and Al) and liberate it into a form that is available and beneficial to plants. The productivity of particularly mineral fertilizers is increased considerably.
• liberate carbon dioxide from soil calcium carbonate and enable its use in photosynthesis.
• help to eliminate chlorosis caused by iron deficiency in plants.
• reduce the availability of toxic substances in soils.

2.3. Biological Benefits:

Humic acids biologically stimulate the plant and the activities of microorganisms. They

• stimulate plant enzymes and increase their production.
• act as an organic catalyst in many biological processes.
• stimulate growth and proliferation of desirable micro-organisms in soil.
• enhance plants natural resistance against disease and pest.
• stimulate root growth, especially vertically and enable better uptake of nutrients. Increased root respiration and root formation.
• promote the development of chlorophyll, sugars and amino acids in plants and support photosynthesis. Raise in vitamin and mineral content of plants.
• thicken the cell walls in fruits and prolong the storing and shelf time.
• increase in germination and viability of seeds.
• stimulate plant growth (higher biomass production) by accelerating cell division, enhancing the rate of formation in root systems, which results in higher yield of dry matter.
• improve the quality of yields, their physical appearance and nutritional value.

Optimal Utilization of Nutrients

Effect in soils

 

Salinized Soils

Salts are split up by the high cation exchange capacity (CEC) of Humic acids. Cations (e.g. Ca and Mg) are bound and chelated. The high osmotic pressure within the root area is reduced.
(s. fig. 2.8, 2.9, 2.10, pic. 2.4).
 

Picture 2.4 — Highly Salinized soil.

Acidic Soils

Due to their high buffer capacity humic acids neutralize acidic soils, which decimate acid caused stress in plant roots. Elements harmful for plants, especially aluminium and heavy metals, are bound firmly and immobilized by humic acids. Hence, their toxicity is reduced and phosphate bound by aluminium is released (s. fig. 2.11, 2.12).
 

Figure 2.11 — Comp. scheme of acidic soils without and with humus acids. 
(Copyright © Humintech 2020)

Alkaline Soils

Alkaline Soil As a result of the high pH value, many essential nutrients and trace elements are not in plant available form. Humic acids buffer the high pH and convert nutrients and trace elements into
plant receptible form by complexation. Phosphate bound by calcium is resolubilized and made available (s. fig. 2.13, 2.12).
 

Figure 2.12 - Humic acid opimizes the soil for the root development, e.g.nutrient uptake, soil aeration, water-holding caoacity, cation exchange capacity (CEC) and the formation of clay-humus-complexes.

Eroded Soils
The addition of humic acids accumulates the organic matter in the topsoil. The erosion is effectively reduced by intensified root formation and stabilizing clay-humus complexes.

Dry Soils
Humic acids increase the ability of the soil to retain water. Thus, water is available for the plants in dry periods too. That way drought caused stress situations to the plants are avoided and the wastage of precious water is reduced.

Pesticide, Herbicide, and Fungicide Charged Soils
Humic acids raise the efficiency of pesticides, fungicides as well as herbicides and immobilize their harmful residues.

3. ECOLOGICAL BENEFITS OF HUMIC ACIDS

The ecological benefits of humic acids are diverse, present profitable and effective solutions for environmental problems along with the preservation of the environment.

First of all, soils with a high content of humic acids are a guarantee for low nitrate leaching and for optimum nutrient efficiency. A well developed root system, which is achieved by a high content of humic acids, prevents that nitrate and pesticides mix in with ground water (s.fig 3.1). Futhermore, a low content of nitrate is an indicator and a prerequisite for appropriate organic agriculture.
It happens very often that growers use fertilizers more than plants can take up. This leads to nitrate concentration in soil, which is later to be found in ground water. As a result, this contaminated water can only be purified by a complex and expensive wastewater treatment process.

Important: Instead of curing the symptoms (water contamination) only, the basic causes (nitrate leaching) need to be tackled.

Secondly, humic acids reduce the over salination problem in the application of watersoluble mineral fertilizers. Humic acids are able to decrease high salt con-tents in soils and thus the resulting toxicities. Especially the NH4-toxicity of fertilizers containing ammonia is reduced, which is of great importance for young plants particularly.

Generally, humic acids reduce root burning which comes about through excessive salt concentrations in soils after fertilization; in case of permanent high levels of salt in soils, these are reduced. Furthermore, when humic acids are mixed with liquid fertilizers, the undesirable smell is diminished.

Thirdly, humic acids are an effective means to fight against soil erosion. This is achieved by increasing the ability of soil colloids to combine and by enhancing root system and plant development.

Leonardite and humate -based products are certificated for organic agriculture by renown organizations and institutions of agriculture worldwide (s. fig 3.1).

4. ECONOMIC BENEFITS OF HUMIC ACIDS

Humic acids chelate nutrient compounds, especially iron, to obtain a suitable formfor plant utilization in soli, so the nutrient supply of plants is optimized. High increases up to 70% in yield, accompanied by a reduction up to 30% in the use of fertilizers and pesticides, as well as better and healthier growth of green grass, ornamentals, agricultural crops and woods can be attained with the regular application of first-quality humic acids. Furthermore, water holding capacity of soils is increased considerably, which means that the use of water can be reduced substantially. Best economic results can be obtained in light and sandy soils poor in humus as well as on recultivation fields.

The diverse positive impacts of humic acids are to be observed particularly in such soils. This is true for almost all soils in dry and warm regions. As a result of the high mineralization rate of organic substances, providing these soils with stable humic acids is indispensable for the maintenance and improvement of soil fertility.

5. HUMINTECH

HUMINTECH® offers a variety of products which successfully fulfil the needs of different soil conditions and plants (s. pic.5.1). As a result, soils treated with HUMINTECH® products secure qualitative and quantitative increases in yield and reduce material and labor costs. Made of humic substances of the highest quality, HUMINTECH® extensive product line has been designed to suit the demands of a healthy community.

Picture 5.1 — Some products of the HUMINTECH® product line