What is the Difference Between Humic and Fulvic Acid

The main difference between humic and fulvic acid is that the humic acid is a large molecule whereas the fulvic acid is a comparatively small molecule. Furthermore, humic acid is not absorbed by plants while fulvic acid is absorbed by plants and it carries nutrients to the plant.

Humic and Fulvic acid are two of the three components of the humic substances found in the organic fraction of the soil, peat, and coal. The third component of the humic substances is humin, which is insoluble in water.

Key Areas Covered

1. What is Humic Acid
     – Definition, Formation, Features, Function
2. What is Fulvic Acid
     – Definition, Formation, Features, Function
3. What are the Similarities Between Humic and Fulvic Acid
     – Outline of Common Features
4. What is the Difference Between Humic and Fulvic Acid
     – Comparison of Key Differences

Key Terms

Absorption by Plants, Fulvic Acid, Humic Acid, Humic Substances, Humification, Molecular Weight

What is Humic Acid

Humic acid is a naturally-occurring organic acid in the deep earth. It becomes important due to its ability to preserve organic minerals and trace elements, making them available for plants. But, due to its high molecular weight, it will not be uptaken by the root system. Also, it protects the root from pathogen attacks while reducing inflammation. It fights against malignant cell growth as well.

Figure 1: Humic Acid

In the animal body, humic acid is involved in replenishing nutrient levels. It aids the function of the immune system as well.

What is Fulvic Acid

Fulvic acid is another natural organic acid occurs in the deep earth as a result of humification. It has a low molecular weight when compared to humic acid. Hence, it can be absorbed by plants. Also, it makes the cell membrane more permeable to up take nutrients into the cell. Therefore, cells can have more usable nutrients.

Figure 2: Fulvic Acid

Fulvic acid inside the body helps the natural detoxification process by binding with water.

Similarities Between Humic and Fulvic Acid

• Humic acid and fulvic acid are two components of the humic substances of soil, peat, and coal.
• Both occur in the deep earth due to the humification of seaweed.
• Also, it is possible to add different combinations of them to the soil.
• Looking at their functional similarity, both stimulate the growth of plants by improving the uptake of minerals.
• Also, they improve the natural resistance of plants to environmental stress.
• Furthermore, inside the body, they help in the digestion and the absorption of nutrients.

Difference Between Humic and Fulvic Acid

Definition

Humic acid refers to a variety of organic acids obtained from organic constituents of humus, which is soluble in water at certain pH levels while fulvic acid refers a variety of organic acids of the humus, which is soluble in water at all pH levels., Hence, the condition for solubility in water is one important difference between humic and fulvic acid .

Formation

Furthermore, humic acid forms from fulvic acid while fulvic acid forms by the humification of seaweed at about 200-250 feet underground.

Color

Also, in appearance, the difference between humic and fulvic acid is that the humic acid is black or dark brown in color whereas, the fulvic acid is yellow to yellowish brown in color.  

Molecular Weight

In addition, there is a difference in their molecular weight too. The molecular weight of humic acid is high while the molecular weight of fulvic acid is low.

Absorption by Plants

Moreover, plants do not absorb humic acid, but absorbs fulvic acid. Thus, this is also a major difference between humic and fulvic acid. 

Function

Besides, another difference between humic and fulvic acid is that the humic acid retains moisture in the soil while the fulvic acid carries nutrients to the plant.

Conclusion

Humic acid is the high molecular weight organic acid found in the soil, which helps to retain moisture. On the other hand, fulvic acid is the low molecular weight organic acid found in the soil, which helps to absorb nutrients faster by the root. Both humic acid and fulvic acid are two humic substances, which represent the organic fraction of the soil. The main difference between humic and fulvic acid is the molecular weight associated role.

Reference:

1. Smith, Harley. “Humic or Fulvic Acid: What Kind Are Your Plants On?” What Is Transpiration? – Definition from MaximumYield, 17 July 2017, Available Here
2. Wells, Katie. “Benefits of Fulvic and Humic Acid on Nutrient Levels | Wellness Mama.” Wellness Mama®, 18 June 2018, Available Here

Image Courtesy:

1. “Humic acid” By Yikrazuul – Own work (Public Domain) via Commons Wikimedia  
2. “Fulvic acid” By Michał Sobkowski – Own work (Public Domain) via Commons Wikimedia