Humic Acid: Your Crop’s Best Friend

When to apply humic acid to increase crop yield.

When to apply humic acid is a question that is asked often. It can be applied at all stages of your crop’s growth; from seed treatment, planting furrow drench, to foliar applications.  Humic acid is biostimulant that, with the aid of microorganisms, makes minerals in the soil available in plant soluble forms. Because it’s a biostimulant it’s not a fertilizer, but an adjunct to your fertilization program 

Whether you use compost, aged manure, or urea the addition of humic acid to your regime means you will need less because it makes all fertilizers more efficient.  

To get your crops off to a good start, a seed treatment with humic acid can be highly beneficial. 

Apply Humic Acid for Seed Treatment

Many farmers, perhaps you, buy pretreated seeds.  They may be pretreated with toxic chemicals and fertilizersIf you use humic acid in your farm management you won’t need those toxic seed treatments. Seeds treated with humic acid have been shown to have 

  • Faster germination rates 
  • Increased nutrition uptakes 
  • Better seedling root development 
  • Less susceptibility to pests and diseases  

Treating your own seed may seem like a bothersome step that you don’t want to take but the benefits far outweigh the effort. The recommended “recipe” to treat 2 pounds of seed with Humic Land, humic acid produced from sustainably sourced black peat extraction, is 

For 1 Kg (2 Lbs.) of seeds you will need: 

6 ml Humic Land = ¼ tsp 
1 Liter water = 1 quart 

Create the solution and soak the seeds for 10 hours. Then dry them to 10% moisture content. A benefit of treating seeds with our product, Humic Land is that it contains humic and fulvic acids, and promotes microbial activity. When you plant treated seeds, you add beneficial microorganisms to your soil. Your seeds are a carrier for the biostimulant, increasing the fertility of your soil as they grow.  Water with any leftover solution for added benefits. Scale this recipe up for larger quantities of seed.  

A study was done by Hartwigsen and Evans, published in the journal Horticultural Science, Vol 35 (7) examining the difference between soaking seeds or substrate drench using humic acid. They examined marigolds, geraniums, cucumbers, and squash. They found seed treatment increased germination rates and that soil drench created stronger root structures. Their conclusion was  App

“…humic acid application as a seed treatment or substrate drench is effective in increasing root fresh weight in cucumber, squash, geranium, and marigold. Therefore, the potential exists for using humic acid to increase root growth of seedlings and improve stand establishment in commercial applications such as plug production.”

That study, and many more, have been conducted in the last 20 years. They have all shown humic acid to be a beneficial seed treatment. In 2020 we conducted seed treatment tests with Humic Land on field corn. We found 23% more nitrogen uptake when soaking seeds. When we added Humic Land as a soil drench root masses increased by 28% to 48%. 

So, if you are feeling pressure to get your crops in and don’t have the time to soak seeds, another beneficial use of humic acid is as a drench in the furrow you’re planting. 

Planting Crops with a Humic Acid Soil Drench 

When you apply humic acid to your cropping rows you give your crops a boost. You will notice an improved ability of your crop to withstand drought (although we all hope this is not a drought year).  A soil drench of humic acid can be combined with a nitrogen fertilizer but contact us, we can advise you how much less nitrogen fertilizer you may need to use.  As the season progresses you will notice your crops  

  • Are stronger and healthier 
  • Have more blossoms and fruit set 
  • Increased yield, at harvest 
  • Increased pest and disease tolerance 

It doesn’t take very much humic acid to make a big difference.  

Your farm will benefit from both crop health and yield, and in the amount of inputs, you don’t need.  Applying humic acid to your crops will impact your bottom line in two ways: less inputs, more production. Which means more money in your pocket.  

Plants have many moving parts. All of them, roots, stems, fruits, and leaves – benefit from humic acid.  After your crop gets a little growth, and before insect pests find it, a foliar spray of humic acid will help your crop survive an insect infestation. 

Foliar Spray with Humic Acid 

You may usually think of foliar sprays as fungicides or pesticides but think of a humic acid spray as a nutrient boost.  It’s also an insect repellant for your crop. 

Soil scientists have found that both root applied and foliar applied humic acid increase a number of plant enzymes that are reacting to a mild stress. Cytokinins and jasmonic acid (JA) both are increased with humic acid applications, especially foliar.  These enzymes act as signalagainst eventual pathogen attacks.  

Plants have amazing defense mechanisms. When an insect, or other animal, feeds on the leaves of a plant it releases JA, which activates protease inhibitors. That just means the plant makes itself no longer a high-quality source of protein for the insect, and the insect moves on. A light foliar spray with humic acid activates JA before an insect gets to take a nibble out of your crop.

Humic acid also enhances plant antioxidant defense systems. The mild stress of the humic acid causes the plant to create chemical compounds, phenols and enzymes. The plant does this because its above ground growth does not naturally come in contact with humic acid. So, the plant senses it as both an external aggressor and a source of nutrients. The nutrients are absorbed and JA is activated as an antibody to what the plant perceives as an antigen. 

When you apply humic acid to your crop at an early developmental stage, you’ll get root elongation (which is beneficial if this should be a drought year). Later sprays will give you greater sugar content, larger fruit size, and heavier grain weight. It will also aid in pest and pathogen attacks.

The mild stress the plant experiences from its leaves coming in contact with humic acid doesn’t cause any decrease in plant vigor or productivity. In fact, field tests have shown a 20% increase in cilantro foliage after use of our humic acid product, Humic Land.  

There are more than drought, pests, and pathogens that can steal your crop.  A silent, and cumulative enemy is the buildup of salts. 

Humic Acid Reduces Soil Salts Buildup 

Many years of irrigation and commercial fertilizers leave fields with buildups of numerous salts; calcium chloride, sodium sulfate, sodium bicarbonate, magnesium sulfate, calcium sulfate, calcium chloride, potassium chloride, and potassium sulfate. One, or more of these will probably sound familiar if you’ve been irrigating for any length of time. They are all naturally occurring but when the water from your irrigation system evaporates from your soil the salts are left behind.  

This seriously affects the fertility of the soil. The greater the salts content in the soil the less water plants have available.  If your soil is crusting or becoming less productive it’s time for a soil test; a detailed salinity analysis.  

Cimrin et al conducted a study on the effect of humic acid on pepper quality and quantity in moderately saline soils. Foliar spray with humic acid was beneficial for soil and plant health.  They found significantly increased levels of N, P, K, Ca, Mg, S, Mn, and Cu in pepper seedling shoots. They also found humic acid was beneficial in root nutrient uptake, including all the above and Zn. Both shoots and roots of the pepper seedlings had decreased levels of Na. They concluded

“…humic acid treatments can ameliorate the deleterious effects of salt stress on pepper plants and humic acid could offer an economical and simple application to reduce problems of pepper production in moderately saline soils.”

The Na content of both shoot and root of pepper decreased, in Cimrin’s study, with the addition of foliar spray of humic acid at 10 days after transplant.   

Humic acid is a mighty tool in your farm management toolkit. Plant health and crop yield are directly tied to soil healthHumic acidis your crops’ best friend because it’s a natural biostimulant, activating microbial activity in the soil that turn minerals into plant-available nutrients. It also enhances your crops’ defense mechanisms.  

For more information on soil health, human health, their interconnections, and Humic Land check out our blogs. Our product, Humic Land is sustainably sourced from peat with as little soil disturbance as possible. It’s a slow-release gel that gives your crops and soil a steady stimulation of soil biology that increases health, productivity, and your farm profit. 

Get our blogs about soil health & regenerative farming straight to your inbox.

Follow us

and find original content on soil health and regenerative farming


Call for Price

I agree to my email being stored and used to receive the newsletter.