In their most general form, humic acid organic fertilizer are the components of humus made up of complex carbon chains composed primarily of carbon, oxygen, hydrogen, nitrogen and sulphur.
These substances resemble a black, hydrophilic powdery substance mined from the earth, with their composition, structure and functional groups varying depending on their age and origin. Nonetheless, the presence of this substance in a soil has a number of benefits on plants grown within the area, with studies showing plants grown on soils containing adequate humin, humic acids and fulvic acids being healthier, less subject to stress, higher yielding, and of higher nutritional value.
Alongside this, the presence of these complex organic compounds (humic substances) within a soil function to provide soil structure, porosity, water holding capacity, available carbon, the promotion of cell growth, improved cation exchange capacity (via the chelation of cations within the soil), and are involved in the chelation of mineral elements. Furthermore, the presence of these substances have also been found to work similar to a surfactant (wetting agent), solubilising hydrocarbons into water phases.
Humic substances are renowned for their ability to improve a variety of soil areas including:
Soil Improvement Properties (mainly due to humic acid )
- improve soil structure, texture, looseness, friability and decrease soil erosion
- improve water holding capacity for better drought resistance and reduction in water usage: (this is because of the large surface area and internal electrical charges humic substances have, allowing them to hold up to seven times their volume in water)
- improve drainage
- increase oxygen in the soil (stimulating microorganisms and providing better aeration)
- buffering properties (prevention of rapid changes in soil acidity related to humic substances and their ability to assist the soil in accepting or donating free hydrogen ions)
- improve soil wetting ability
Mechanical Improvements (humates)
- support larger, stronger root systems via favourable conditions
- desirable environment for beneficial microorganisms and stimulate soil biological activity (good source of energy for soil organisms)