Humates: small-scale applications

🚿Why humates + How-To use a hose-end sprayer

In this post we’ll cover the following:

• What are humates (brief review)

• Why use humates

• How-To start incorporating humates (for small-scale applications)

Let me preface this post by acknowledging that most humate products are mined and/or heavily processed and it’s difficult to find clear information regarding the varying quality and ethics within the industry 😵‍💫 I’m currently researching this topic and plan to write about my findings soon. My goal is to be able to think through humate options responsibly - whether purchased or self-made - and feel good about what I use on a per project basis.

For now, just know not all humate products are created equal, do not fall for bullshit greenwashing claims, use sparingly, and prioritize shopping with brands that are transparent with you about their practices.

What are humates & Why are they useful?

From a recent overview of different kinds of organic matter:

Humates are basically the end of the road of decomposition - the final molecular structure of whatever didn’t get used by the living organisms that contributed to the breakdown process. Humates can be derived from ancient biological sources like coal or more recent decomposition like composts or fertile soil. “Humates" is a catch-all term that refers to both liquid humic acid and solid or pelletized humates - chemically, they’re very similar.

The remarkable thing about humates is their molecular structure which, with all those versatile carbon atoms, allows them to grab onto many different kinds of chemicals - be it toxins like herbicides and fungicides, or plant nutrients from mineral or synthetic sources (which prevents leaching).

I kind of think of humates as a buffering system for the soil - if there is an excess of something, humic acid will “complex” it into its matrix curbing effects of toxicity, or on the other hand if there is a shortage of something, humic acid can hold onto it until it is needed by plants or other life. Lastly, fungi can feed on humic acid and improving fungal populations leads to more aggregation which equates to better soil structure.

From the innumerable potential benefits that humates can provide to a soil, here are a select few that strike me as relevant to the context of today’s how-to:

• Ensures irrigation water is not suppressing microbial activity

• Feeds fungi in the soil or compost to which it’s applied

• Complexes any harmful substances that were introduced historically, or currently via run-off, from neighboring sites

• Improves plant nutrient availability (including phosphorus!)

• Contributes to improved soil structure

The benefit I’ve been most excited about lately is the increase in fungi and spores in my thermophilic composts when I lightly feed humic acid during watering. Below is a testate amoebae with a belly full of fungal spores, found in my compost 😆(400x total mag)

How can I start using humates?

One easy way to start incorporating humates in small-scale contexts is by using a hose-end sprayer which can be used for nearly any hand watering tasks whether you’re wetting compost, watering in seeds or seedlings, giving trees an extra drink, hose watering a small yard, etc. 

Here is my hose-end sprayer :) 

LEFT: As water moves from the hose (left) to the sprayer head (right) it creates a siphon effect which pulls the liquid in the container up through a straw/tube, effectively incorporating the solution into the hose water. RIGHT: a view of the sprayer control (gray) and the dial for application rate (yellow)

Humic acid concentrate made from powder. I keep plenty of air in here and store in my garage which, according to the microscope, seems to work fine! PS: If my husband is reading, this is where that Nalgene went… 😬

How to apply humates using a hose-end sprayer:

For the purposes of this demo, I will focus on using a humate product which can achieve a higher concentration than the humic acids extracted from an excellent source of compost (though the latter is very useful too in many contexts - we’ll get into this more in an upcoming post!)

To start, hose water is turned OFF, the hose-end sprayer head is attached to the hose, the sprayer jar is detached.

1. Create a concentrate: If the humate is a dry powder or pellet, thoroughly mix in water in a separate container at the product's instructed rate of dilution. If using a liquid humate you can mix directly in the sprayer jar at the instructed dilution rate.

   Why: we want to avoid having sediment in the sprayer jar. If pellets or powders don’t dissolve entirely, consider sieving through a coffee filter, cheesecloth, or mesh of some kind. Being diligent up front will save lots of time dealing with a clogged sprayer.

1. Attach the siphon tube to the sprayer head

2. With the sprayer control in the OFF position, turn the hose water on: no water should come out unless you move the sprayer control to an ‘on’ position

3. Add pre-mixed humate to the sprayer jar, top off if necessary: you can either fill your pre-mixed solution all the way to the highest mark on the jar or you can fill the jar part way and further dilute the concentrate by topping off with some hose water using the sprayer controls

4. Test out the siphon: with the sprayer still detached from the jar, turn the sprayer setting ON (at any rate) and see if the solution in the jar is actually being siphoned up into the tube

   Why: sometimes it’s hard to tell as you’re watering if the solution is actually making its way into the water, so this will provide some peace of mind that it’s working properly and give you a chance to troubleshoot if its not (here’s a great video for troubleshooting)

5. Attach sprayer to jar: with the sprayer in the OFF position, hold the sprayer head steady and spin the jar onto the threads (this is the opposite of how you’d typically put a lid on a jar, instead thread the jar onto the lid)

6. Choose a rate of application: does your scenario call for a light feeding or a heavy feeding? Adjust the dial on the sprayer accordingly.

7. Provide humates to whatever you wish!

8. Clean the god*amn sprayer: if you have excess humates, store it in a partially filled jar (to allow it some air) or add foil over the jar it’s already in, and be sure to rinse the sprayer head and siphon tube by running the hose for a few seconds with just water, no solution in it before allowing it to fully dry, then store the sprayer equipment out of direct sunlight

Concluding Thoughts

Conventional land management practices have resulted in the loss of humates that would otherwise accumulate in a healthy, functional soil system. Truly regenerative soils produce their own humate compounds, as do thriving biologically active composts. Humate products are simply a tool we can use in the restoration process and in making even good compost, more fungal (which so many of our soils need).

Got Questions? Comment below or share them next Friday on our upcoming Office Hours thread.

Go make some soil 😎