Fulvic acid is the component with the smallest molecular weight and the largest activity in humic acid. And it is the essence of the active ingredients of humic acid. It is a gray-black powdery substance soluble in water, it is a plant growth regulator that can promote plant growth.
- Important in combating drought
- Can improve plant resistance
- Yield increase and quality improvement
Specific characteristics of fulvic acid:
- It has a small molecular weight and is easily absorbed and utilized by plants;
- The content of functional groups of fulvic acid is more, the physiological activity is greater than that of general humic acid, and the complexing ability to metal ions is relatively strong;
- Humic acid cannot be directly dissolved in water, it needs to be converted into potassium, sodium and other monovalent metal salts or ammonium salts to dissolve in water. The aqueous solution of these salts becomes alkaline, while fulvic acid can be directly dissolved in water, and its aqueous solution becomes acidic.
The effects on soil, fertilizers and plants in the agricultural field:
1. Physical effect of fulvic acid:
Improve soil structure. Prevent soil cracking and erosion, increase soil water holding capacity, and improve cold resistance. Darken the color of the soil, which is conducive to the absorption of solar energy. the
2. Chemical action of fulvic acid:
- Adjust soil pH value and increase soil buffer capacity
- Improve and optimize plant uptake of nutrients and water
- Rich in organic matter and minerals necessary for plant growth.
- Improve the solubility of organic fertilizers and reduce the loss of fertilizers.
- Transform various nutrients into a state that is easily absorbed by plants.
- It can enhance the absorption of nitrogen by plants and reduce the fixation of phosphorus.
- It can protect and store nitrogen, phosphorus, potassium and other elements that penetrate into the soil in the soil, and can accelerate the process of nutrients entering the plant body, improving the application effect of inorganic fertilizers.
3. Biological effects of fulvic acid:
- Stimulates the growth and reproduction of beneficial microorganisms in the soil
- Improve the ability of plants to resist natural diseases and pests
Detailed explanation of the role of fulvic acid:
1. Improve soil aggregate structure:
Fulvic acid belongs to humus substances. It can affect the properties of the soil, promote the formation of a more stable aggregate structure in the soil, increase the aggregate content of ≥0.25mm in the soil by 10-20%, and increase the organic matter content by 10%. Keep the soil moisture and increase ventilation, which is conducive to the growth of crops.
2. Enhance the water retention of soil:
It is a kind of hydrophilic colloid with strong water absorption capacity. The maximum water absorption can exceed 500%, and the weight of water absorbed from the saturated atmosphere can reach more than twice its own weight. Mineral colloids are much larger; fulvic acid inhibits crop transpiration, slows down soil water consumption, and increases soil water content accordingly.
3. Enhance soil fertility:
Fulvic acid itself is an organic acid, which not only increases the dissolution of minerals in the soil, provides soil nutrients, but also increases the availability of nutrients through complexation. As an organic colloid, fulvic acid has positive and negative charges, which can absorb anions and cations, so that these nutrients can be stored in the soil and will not be lost with water, and improve the utilization rate of fertilizers, which is of great significance in sandy soil.
4. Adjusting the pH of the soil solution:
Fulvic acid and fulvic salts can transform into each other to form a buffer system, thereby regulating the pH of the soil solution.
5. Reduce soil salinity:
The colloidal structure formed by fulvic acid complexation and chelation of metal cations in the soil and its porosity (larger specific surface) can absorb ions or molecules in the soil solution and reduce the concentration of soil solution salt.
6. Physiological effects:
It contains a variety of oxygen-containing functional groups, which determine its physiological activity, thereby regulating life activities, promoting the growth and reproduction of beneficial bacteria, and inhibiting the number of harmful microorganisms; the carboxyl and phenolic hydroxyl groups in fulvic acid have Must inhibit the role of the virus.
