Humic acid is the remains of animals and plants, mainly the remains of plants. It is a kind of macromolecular organic weak acid mixture accumulated after the decomposition and transformation of microorganisms, as well as a series of changes in geochemistry and physics. According to their different solubility and color in different solvents, they are divided into types: fulvic acid, brown humic acid and black humic acid .
- Fulvic acid: Strong acidity, has a good complexation effect on metal ions, moves faster in plants, and has a stronger stimulating effect;
- Black humic acid: It migrates slowly in plants, has a slow stimulating effect, is easily absorbed by the surface of plants, and has a good effect on promoting root growth;
- Brown humic acid: It contains moderate oxygen active groups, and has slow migration in plants and moderate stimulation. Humic acid widely exists in soil, peat, lignite, weathered coal, oceans, lakes and swamps, and natural water also contains a small amount of humic acid.
The total amount of humic acid contained in the soil is the largest, but the average content is less than 1%; the total amount contained in brackish water is also a lot, but the concentration is lower, and it is impossible to develop it as a resource. Among them, the most promising humic acid resources to be developed and utilized are some geothermal value coals, such as peat, lignite and weathered coal, whose humic acid content reaches 10-60%.
Fulvic acid is a high-efficiency macromolecular organic compound. It is the water-soluble part with the smallest molecular weight and the highest content of active groups among humic acids. The interaction of its functional groups reflects a variety of specific physical and chemical characteristics. After entering the organisms of animals and plants, it can exert a variety of physiological functions, and act on the metabolism of animals and plants by inhibiting or activating enzymes, reflecting obvious stimulating effects.
1. Humic acid
Definition: A group of humic substances with relatively large molecular weight, which can only be dissolved in dilute alkali solution, not soluble in acid and water, have the structural characteristics of aromatic, aliphatic and various functional groups, and are black or brownish-black amorphous organic weak acid mixture .
Sources: Mineral humic acid: humic acid contained in weathered coal, lignite, peat and other minerals.
Biogenic humic acid: the biomass by-products of industrial and agricultural production are converted by chemical or microbial fermentation process into humic substances, which can only be dissolved in dilute alkali solution, and cannot be dissolved in acid and water.
2. Fulvic acid
Definition: a group of humic substances with a small molecular weight, which can be dissolved in dilute alkali solution, acid and water, and the dilute solution is yellow or brownish-yellow amorphous organic weak acid mixture.
Sources: Mineral source fulvic acid: using weathered coal, lignite, peat and other minerals as raw materials, extracted or prepared by chemical process, it can be dissolved in dilute alkali solution, acid and water, and the dilute solution is yellow or brown. components.
Bio-sourced fulvic acid: It is produced from the biomass by-products of industrial and agricultural production through chemical process or microbial fermentation process. It can be dissolved in dilute alkali solution, acid and water, and the dilute solution is yellow or yellow. Brown-yellow component.
3. The differences:
1. Humic acid contains fulvic acid, which is only one of the humic acids
Although both humic acid and fulvic acid are derived from organic acid mixtures that widely exist in nature, both are also derived from natural substances (such as weathered coal, lignite, peat and other minerals) or biological residues (such as Plant stalks, etc.) are extracted. However, fulvic acid is the essence product further extracted from humic acid, that is to say, humic acid includes not only fulvic acid, but also other substances (such as brown humic acid, black humic acid, etc.), but fulvic acid is the most active substance in humic acid (belonging to the most essential substance in humic acid), and fulvic acid is also the core substance for forming a good soil aggregate structure in farmland (the higher the content of humic acid in the soil, the stronger the soil fertility) .
2. The functional focus of them is different
Although both humic acid and fulvic acid can improve soil, cultivate soil fertility, promote absorption, enhance fertilizer efficiency, take root and strengthen trees, and improve resistance, etc., the functions of humic acid are more comprehensive and comprehensive, and its most prominent function is Related to “soil”, mainly to improve the soil:
- Improve soil aggregate structure,
- Improve soil porosity and permeability,
- Improve the bad condition of saline-alkali land,
- Increase the number of soil microorganisms,
- Activate and release soil nutrients to promote absorption,
- Degrade soil heavy metal ions and other harmful substances residues
As the most active substance in humic acid, fulvic acid has a relatively specific function, but its effect is more efficient and prominent. Generally speaking, the most prominent functional effect of fulvic acid is to promote the growth of crop roots and regulate the growth of crops.
Therefore, the functions of humic acid and fulvic acid fertilizer products are different: one is more beneficial to farmland soil (it is better to use humic acid to improve and regulate soil), and the other is more beneficial to crop growth and development (promoting and regulating crop growth It is better to use fulvic acid), if you want to achieve comprehensive purposes, choose humic acid, and choose fulvic acid for root promotion, growth regulation, drought resistance and disease prevention.
3. Different absorption effects
Generally speaking, the smaller the molecular weight of a substance, the easier it is to be absorbed by crops. In other words, the smaller the molecule, the faster the crop can absorb it, the higher the absorption utilization rate, and the faster the effect. In terms of humic acid and fulvic acid alone, the molecular weight of substances in humic acid is relatively large, and the molecular weight of substances in fulvic acid is relatively small.
4. The water solubility is different
Compared with humic acid, fulvic acid has better water solubility. Because fulvic acid can be well dissolved in acidic solution, weak alkaline solution and clear water, while humic acid can only be dissolved in weak alkaline solution but not directly in acidic solution and clear water.
5. The appearance and color are different
The liquid color of the diluted and dissolved humic acid is generally brown-black or dark black, while the liquid color of the diluted and dissolved fulvic acid is generally yellow-brown or yellow-brown.
6. The source affects the quality effect
Both have two sources: one is natural mineral source (mineral humic acid, mineral fulvic acid), and the other is artificial biochemical source (biochemical humic acid, biochemical fulvic acid).
Natural mineral sources are mainly extracted from natural minerals such as lignite, weathered coal, and peat that have been deposited for a long time.
The artificial biochemical sources are mainly produced by human beings through chemical process extraction of plant straws, wood chips, sucrose residues, biological residues and other organisms.
In terms of quality and effect alone, mineral humic acid is better than biochemical one, and mineral fulvic acid is stronger than biochemical one.
7. Humic acid and fulvic acid are effective when used together with nutritional fertilizers
They contain very few nutrients and have very little effect on supplementing nutrients for crops. If you want them to exert better effects on field crops, you generally need to mix them with large, medium and trace elements. Fertilizers and microbial bacteria can be used together to exert greater value.
8. Other matters needing attention in the usage
- Humic acid or humic acid-containing fertilizers are the first choice for soil improvement (humic acid water-soluble fertilizer, humic acid macroelement water-soluble fertilizer, potassium humate, sodium humate, etc.), and fulvic acid or humic acid is the first choice for root growth promotion, disease prevention and drought prevention. Fertilizers containing fulvic acid (potassium fulvic acid, etc.).
- Whether you buy humic acid or humic acid fertilizer, or buy and use fulvic acid or fulvic acid fertilizer, try to choose humic acid and fulvic acid from mineral sources (weathered coal, lignite, etc. as raw materials for production).
