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Writer's pictureJohn Kowalski

Fulvic Acid Use for Cannabis Plants

Updated: Apr 25, 2023


Fulvic acid is the ultimate cannabis growth enhancement that infuses your watering with trace minerals, macro minerals, amino and organic acids, and phytochemicals from a prehistoric compost. Our internal and customer testing has proven excellent results and through a quick web search unveils a vast quantity of additional research.


Taking a step back:


Fulvic acid is a result of the microbial breakdown of organic matter in soils, known as humus. Humus contains humic acid. Within humic acid, a sub-set of smaller molecules develop known as the fulvic fraction.

Fulvic molecules chelate (bind) minerals in the soil creating fulvates. Fulvic molecules also exist in a free-form state meaning an acid that has no mineral attached.

The two forms of fulvic acid have a double action for plants and animals. The chelated minerals are easier for roots and cells to use, and the free-form fulvic activates your feed.

Our AGT-50 is fulvic-dominant and has both fulvates and free-form fulvic acid, as well as trace elements, other organic, and amino acids, plus phytochemicals.


In a recent Alchimia article they note “The use of humic and fulvic acids is becoming increasingly popular among all types of cannabis farmers, who can now take advantage of a healthy, rich and living soil that produces happy plants and therefore abundant harvests. Thanks to this substances, nutrient uptake and management are much more efficient, and root growth is simply spectacular.

Fulvic acids are applied via foliar spraying providing nutrients that are quickly absorbed by the plant. They can also be used via irrigation mixed along with your regular nutrient solution. They're ideal as fast-acting agents, being excellent root boosters.” Summarized below are potential benefits of using humic and fulvic acids:

  • Water retention, microbial activity and cation exchange are significantly increased

  • Improvement of drainage and buffering capacity of the soil

  • Better nutrient uptake (chelating action) and mobility, also via foliar spray

  • Soil toxins are less available for the plants

  • Plant metabolism is enhanced, being ideal for seed germination, rooting and transplantation

  • Enhancement of cell division, improving growth rates

  • Photosynthesis is stimulated, being ideal for plants in shady areas (especially when fulvic acids are applied via foliar spray)

Bozena Sera from Comenius University in Bratislava’s research abstract states, “Hemp seed (Cannabis sativa L.) were treated with humic substances obtained from various soil substrates. Aqueous solutions (200 mg / l) of humic acids (4 types) and one fulvic acid were used. The germination test was performed on Petri dishes under laboratory condition. The results obtained have to be critically analyzed with respect to the potassium content in the humic substances. Perspective results were monitored in seeds reactions to fulvic acid isolated from the O1 horizon (Březník, Šumava) and to humic acid isolated from lignite (Mikulčice).”


Our retail distributor, Mr. Fulvic, has a great article on Ganjapreneur, “To understand the effect Mr. Fulvic could have on cannabis plants the team conducted two controlled studies. One of these studies compared a crop of cannabis plants that were watered with their regular nutrient regimen and one that was watered with Mr. Fulvic. In this study, by the third week in vegetative growth, the plants showed distinct advantages in growth rate, height, size, number of leaves, leaf size, and water consumption. By the ninth week, the cannabis crop being fed Mr. Fulvic was 20% taller than the control group with a substantially higher number of flowering sites. These plants also showed more robust flower growth in the lower canopies and significantly better roots. By week twelve each crop showed nearly equal THC content, but the plants watered with Mr. Fulvic tested with 11.8% more terpenes along with 20.9% higher yield.”


Kevin Klein also published on Cannabis Training University titled The Benefits of Fulvic and Humic Acids in Growing Cannabis. He highlights, “More cannabis growers are taking advantage of the pros associated with fulvic and humic acid. For one, they are good for ensuring that the roots are healthy, and that the uptake of nutrients is better. This will eventually assure that you enjoy larger yields. If you are looking for growth enhancers that are natural, then you should choose fulvic and humic acids when growing cannabis.”

Digging more into the research, an article published in Frontiers in Plant Science titled Impact of N, P, K, and Humic Acid Supplementation on the Chemical Profile of Medical Cannabis (Cannabis sativa L), dives into the science (and impact) behind adding mineral nutrition. “These findings have led many to believe that HA supplementation can enhance the biosynthesis of therapeutic secondary metabolites in medicinal plants. This is especially the case with cannabis, where HA is claimed to increase production and a number of HA-based products are marketed for cannabis cultivation.”


To assist with achieving optimal yield, we recommend considering the outstanding results of the above scientific findings. Science has proven again and again that a well-rounded health and growth program can, without a doubt, help reach your desired outputs.


For more information on AgTonik information for livestock, soil, specialty produce, and more, contact us today.


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