Humic Acid vs. Fulvic Acid: Uncovering the Key Differences
Humic and fulvic acids are complex organic substances found in healthy, fertile soil. They play a critical role in plant nutrition and soil health. But what exactly are they, and what's the difference between humic acid and fulvic acid? This article will break it down for you.In the figure below,on the left is our company's fulvic acid, and on the right is our company's humic acid
1.What is Humic Acid?
- Humic acid is a major component of humus, the organic portion of soil. It forms through the natural decomposition of plant and animal matter by soil microbes. Humic acid molecules are large, with high molecular weights ranging from 10,000 to 100,000 Dalton. They are dark in color.
- The composition of humic acid can vary depending on the source, but generally contains carbon, oxygen, hydrogen, and nitrogen. Under acidic conditions, humic acid is not water soluble. However, it dissolves readily in alkaline environments.
- Humic acid attaches to positively charged soil minerals like calcium, magnesium, and iron. This prevents nutrient lockup, making essential nutrients more plant-available. The large humic acid molecules also help retain moisture in soil.
- In addition to providing nutrition, humic acid stimulates beneficial microbial activity in soil. It also promotes root growth and acts as a chelator, binding to toxic metals like aluminum and removing them from soil solution.
- Overall, humic acid improves soil structure and fertility. It creates an optimal environment for plants to thrive.
2.What is Fulvic Acid?
- Fulvic acid is another component of humus, like humic acid. However, fulvic acid molecules are much smaller than humic acid, with molecular weights ranging from 1,000 to 10,000 Dalton.
- Fulvic acid remains dissolved in water under all pH conditions, while humic acid precipitates out in acidic environments. It is light yellow to brown in color.
- The elemental composition of fulvic acid is similar to humic acid, containing carbon, oxygen, hydrogen, and nitrogen. However, it has almost twice the oxygen content as humic acid.
- Due to its low molecular weight, fulvic acid is an excellent natural chelator. It readily binds to positive soil nutrients like calcium, potassium, and magnesium, forming soluble mineral complexes. This makes the minerals more bioavailable for plant uptake.
- Unlike the larger humic acid molecules, fulvic acid is small enough to readily enter plant roots and leaves. This allows it to efficiently transport nutrition within plants.
- Fulvic acid also enhances cell membrane permeability, allowing for faster absorption of nutrients into plant tissues. For this reason, it is very effective when applied as a foliar spray.
3.Key Differences Between Humic and Fulvic Acids
Though humic and fulvic acids are closely related, there are some key differences between them:
- Solubility: Fulvic acid is water soluble at any pH, while humic acid precipitates out under acidic conditions.
- Size: Fulvic acid molecules are much smaller than humic acid, with lower molecular weight.
- Composition: Fulvic acid contains almost twice as much oxygen as humic acid.
- Function: Humic acid acts primarily to improve soil structure and fertility. Fulvic acid is more active at chelating nutrients and transporting them within plants.
- Usage: Humic acid is applied mainly to soil to release and retain nutrients. Fulvic acid works well when sprayed directly on leaves.
4.Benefits of Humic vs. Fulvic Acids for Plants
Though they have some distinct properties, humic and fulvic acids work synergistically together to benefit plants in several ways:
Humic Acid Benefits
- Improves soil structure
- Increases nutrient availability
- Stimulates microbial activity
- Promotes root growth
- Chelates toxic metals
- Improves soil water retention
Fulvic Acid Benefits
- Chelates and transports nutrients
- Improves cell wall permeability
- Enhances nutrient absorption
- Stimulates plant growth
- Is effective in foliar sprays
- Promotes microbial activity
5.Using Humic and Fulvic Acids Together
Most horticulturalists recommend using both humic and fulvic acids together to optimize plant nutrition and soil health.Though some products contain just one or the other, the two work synergistically to maximize benefits. Humic acid conditions soil while fulvic acid shuttles nutrients into plants.Look for high quality products that contain both humic and fulvic acids. Follow label instructions for best results.For most growth stages, adding these acids to soil is beneficial. Fulvic acid foliar sprays are great for seedlings and transplants. Always avoid spraying flowers, as the acids may interfere with pollination.Investing in quality humic and fulvic acid supplements can really boost plant performance and improve the sustainability of your soil. Give them a try in your garden!