# Foliar humic acid



## davegravy (Jul 25, 2019)

We started discussing this in another thread but it was getting pretty off topic. Does anyone have any insight into benefits (if any) of foliar humic?

The discussion so far:



occamsrzr said:


> davegravy said:
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> 
> > bernstem said:
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## davegravy (Jul 25, 2019)

Can anyone corroborate if humic acid causes FS to precipitate?


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## Babameca (Jul 29, 2019)

No, except if you apply urea as foliar and want to 'chelate' it. Minimal quantities will be needed and not much other benefit will be seen. Instead, you can simply water the urea in.
Oh, and if as me, you apply 'freely' your neighbors earthworms will move into your lawn and create you such a headache....


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## occamsrzr (Apr 27, 2020)

Thanks for starting a new thread, @davegravy!

I think most of my reasoning behind not using FS + Humic came from mostly hearsay and I don't mean to spread any misinformation. Some mention in the FAS thread having issues of using FS with Humic and seeing "flakes". I'm not sure if this is actually an issue or not and haven't been able to find a primary resource on this. https://thelawnforum.com/search.php?keywords=humic&t=211&sf=msgonly

There have been some interesting studies looking into using Humic Substances as a chelator of Iron. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538904/

What they show is Water Extracted Humic Substances (WEHS) are better capable of the uptake of iron when compared to other natural chelators (like Fe-citric acid). The humic substances also helped with the upregulation of genes that help bring Iron into the plant. What I'm not sure is if they went into differentiating between foliar and root uptake of these Humic Substances. Knowing that Fulvic acid is soluble in water across all pH levels whereas Humic acid is only extractable in high pH, they likely had a high amount of Fulvic acid in their WEHS and this Fulvic acid + Iron chelation likely had some foliar uptake.

Interested to see more info on this topic.


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## davegravy (Jul 25, 2019)

occamsrzr said:


> Knowing that Fulvic acid is soluble in water across all pH levels whereas Humic acid is only extractable in high pH,...


Ahh... This is good to know. I was considering adding humic *and* citric acid to my FAS but sounds like I should choose one or the other, and probably citric acid.


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## davegravy (Jul 25, 2019)

Babameca said:


> Oh, and if as me, you apply 'freely' your neighbors earthworms will move into your lawn and create you such a headache....


 :lol: the earthworm love hate relationship


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## Babameca (Jul 29, 2019)

@davegravy Too polite gets weird. I hate them by now.
Don't mix Humic with anything is the best call. Interaction with other soil applied products is not even cleared yet.
For FAS, CA and you can spice it up to N to taste :bandit: .
I run, as many, my PGR in it and my Kelp, plus 0.1N/M from Umaxx for the summer months. :nod: :bandit:


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## bernstem (Jan 16, 2018)

I have not tried Humic or Fulvic acid with Iron. Fulvic acids are small enough to be transported across cell membranes and are believed to transport across leaf surfaces into the plant. They would be my choice to try and chelate iron for foliar application. I looked at a few of the papers on whether Humic acid is absorbed by leaves and I remain skeptical. Even the studies that seem to show it can cross leaf surfaces did not show a lot of movement.

Looking at the effect on growth and plant health seems to be much clearer. Foliar application of Humic acid is good for plants. So is soil application. None of the studies I saw (though I didn't look too hard) looking at foliar application compared the effect to soil application as a control so I can't tell if the Humic acid applied foliarly was any different than soil application. It could be that foliar application of humic acid gets washed into the soil and works there rather than doing something on the leaf blades.


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## turfnsurf (Apr 29, 2020)

bernstem said:


> I was under the impression that Humic acid is too big and not taken up by plants so foliar application shouldn't do anything. Fulvic acids, however, can be taken up, but I don't know if that is only in roots or also at leaves. If that is wrong, someone correct me please.
> 
> I water in my Humic. I apply Humic spring, summer, and fall on a biweekly or so schedule.


@bernstem I am going to be applying humic acid with RGS today. I wasn't aware that this could be applied through the fall as well (which is good to know). Is there a maximum or minimum temp that you apply this at?

@davegravy I am new to this - why do you want to apply humic acid foliarly? My understanding is that humic acid to correct the soil...so while I intend to spray mine foliarly because I am combining it with my liquid fert app, I intend to wash it into the soil the next day. Unless I misunderstand you, you intend to apply foliarly, and leave it as is and I am trying to understand why.


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## bernstem (Jan 16, 2018)

@turfnsurf I apply 1 Tbsp/1000 square feet. I don't think you can reasonably apply too much humic acid without going broke. I have seen recommended rates of 5-10 lbs/1000 square feet incorporated into the top 3 inches of soil twice per year for gardening.

I have never seen grass injury from Humic acids and I apply at any temperature.


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## occamsrzr (Apr 27, 2020)

turfnsurf said:


> bernstem said:
> 
> 
> > I was under the impression that Humic acid is too big and not taken up by plants so foliar application shouldn't do anything. Fulvic acids, however, can be taken up, but I don't know if that is only in roots or also at leaves. If that is wrong, someone correct me please.
> ...


I think there is maybe a misunderstanding what Humic Acids are and in the marketing of these, something gets lost in translation. If you're going to be applying something like Humic 12 or RGS, this isn't an all or nothing of just Humic Acid. Both of these are derived from Leonardite and have a wide range of Humic Substances. John from Green County Fert put out a video discussing this: 




In the video, he takes Humic 12 and separates the Fulvic Acid from this. He states that all of the Humic used in GCF products will contain some Fulvic acid.

Knowing that foliar application of Fulvic Acid will result in uptake in the leaf tissue, there are benefits of this. This allows these molecules to have biostimulant effects right away. It also allows for it to "carry" other nutrients through the cell walls and be usable right away. See the article about iron uptake I posted above for an example. I think there are benefits of foliar applications of Humic Substances even if the current science doesn't know how much benefit comes from foliar uptake and how much comes from root uptake.


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## corneliani (Apr 2, 2019)

davegravy said:


> Can anyone corroborate if humic acid causes FS to precipitate?


This older thread has some feedback from @Greendoc that you may find relevant. He does mention some Humics and FS not mixing well. 
https://thelawnforum.com/viewtopic.php?t=2990

I'll also add that I had a conversation with Chris from GCF earlier this year and amongst the myriad of tidbits offered, he mentioned to be careful with carbons & metals (I assumed it was due to the metals being heavy & wanting to fall out of solution). Not sure if it was due to any HA / FS solubility issue but considering they have products like the 0-0-2 MictoGreene with 8% HA and 6% Iron, it doesn't seem impossible to mix the two.


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## turfnsurf (Apr 29, 2020)

occamsrzr said:


> In the video, he takes Humic 12 and separates the Fulvic Acid from this. He states that all of the Humic used in GCF products will contain some Fulvic acid.


I wasn't aware of this prior to watching the video or reading your post. It's not important if you don't know...but do you know if fulvic acids are generally in all humic products? I don't know that I will be changing from Humic12, but if I do, I'd like to know how to look for the fulvic acid if it's _not _in other humic products.



> Knowing that foliar application of Fulvic Acid will result in uptake in the leaf tissue, there are benefits of this. This allows these molecules to have biostimulant effects right away. It also allows for it to "carry" other nutrients through the cell walls and be usable right away. See the article about iron uptake I posted above for an example. I think there are benefits of foliar applications of Humic Substances even if the current science doesn't know how much benefit comes from foliar uptake and how much comes from root uptake.


So even though I didn't know this until today, I would have inadvertently benefited from the foliar absorption of the fulvic acid prior to me washing down my Humic12 the next day. Now it makes sense why I was reading about people washing it into the soil as opposed to just applying it straight to the soil (which is what I thought people would do since I thought the product was only beneficial to the soil). Nice.


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## occamsrzr (Apr 27, 2020)

corneliani said:


> davegravy said:
> 
> 
> > Can anyone corroborate if humic acid causes FS to precipitate?
> ...


Ah, thanks a ton for finding this post. I think this was the post that led me to using my K4L's Fulvic with my FAS applications. I've been having luck and not seeing any issues with this mix. I've had issues with dissolving K4L's Extreme Blend as the Humic tends to leave a bunch of black specs behind. I would love to try getting some straight L-Amino Acids as these are also supposed to be great chelators and also have some biostimulant effects.


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## occamsrzr (Apr 27, 2020)

turfnsurf said:


> occamsrzr said:
> 
> 
> > In the video, he takes Humic 12 and separates the Fulvic Acid from this. He states that all of the Humic used in GCF products will contain some Fulvic acid.
> ...


I think this is rad overall. We've likely seen some benefits from Fulvic uptake regardless of knowing. I'm not sure if it practically makes a difference if we know how much is absorbed via the leaves vs roots. I guess it's just not as important to water it in right away.

As far as fulvic acids generally being in humic products, I think it really depends. As far as the GCF products, I think one of the reasons why they leave it off the label is because of differences in regulation between different states. I've used some Kelp4Less products and they seem to separate out Humic from Fulvic in their packaging. I would think most others are more similar to GCF. For example, both LawnStar and Simple Lawn Solutions market their Root Hume as being a blend of both Humic and Fulvic acids.

https://simplelawnsolutions.com/products/raw-organic-humic-fulvic-acid-root-hume-32oz
https://getlawnstar.com/products/root-hume-concentrate/


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## davegravy (Jul 25, 2019)

turfnsurf said:


> @davegravy I am new to this - why do you want to apply humic acid foliarly? My understanding is that humic acid to correct the soil...so while I intend to spray mine foliarly because I am combining it with my liquid fert app, I intend to wash it into the soil the next day. Unless I misunderstand you, you intend to apply foliarly, and leave it as is and I am trying to understand why.


I already do apply humic as part of my soil correction applications, but the  vendor where I buy the humic claims it has benefits both for soil application and foliar. They don't offer any scientific evidence for it, hence the question. I'm considering also adding it to my foliar FAS sprays depending on if it might be beneficial and it's not going to precipitate out the iron or anything like that.


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## turfnsurf (Apr 29, 2020)

I have a question about watering in humic acid (and RGS)

How long after foliar application should I be watering this in?
Since I will be walking on my lawn using my watering hose, about how long should I be watering the treated areas?


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## occamsrzr (Apr 27, 2020)

turfnsurf said:


> I have a question about watering in humic acid (and RGS)
> 
> How long after foliar application should I be watering this in?
> Since I will be walking on my lawn using my watering hose, about how long should I be watering the treated areas?


Are you applying this with a hose-end sprayer? I don't think you need to water it in if so.


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## turfnsurf (Apr 29, 2020)

occamsrzr said:


> turfnsurf said:
> 
> 
> > I have a question about watering in humic acid (and RGS)
> ...


I am using a backpack sprayer. Chapin 24V which holds 4 gallons.


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## occamsrzr (Apr 27, 2020)

turfnsurf said:


> occamsrzr said:
> 
> 
> > turfnsurf said:
> ...


Ah, if that's the case, I think the general rule is 4 hours after application, most everything that can be absorbed will be absorbed by the leaves by then. RGS doesn't really have anything that can burn the leaves so you should be good without watering in or timing it before a rain.


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## MarshalOfFire (Apr 22, 2020)

I also use a 4gallon backpack sprayer to apply RGS.

RGS and other humic products cover the leaf blade with visible product. I prefer to water it in or time it with rain just so my yard doesn't look orangeish.


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## occamsrzr (Apr 27, 2020)

If anyone has two hours to spare. There is a lot of good info concerning this topic from a recent show on The Grass Factor:

https://www.youtube.com/watch?v=FG4XpNqlNoA

I think it confirms a lot of what was talked about here as well as provides some times where humic and/or fulvic are a good fit in the lawn. It goes deep into the science behind all of this.


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## davegravy (Jul 25, 2019)

occamsrzr said:


> If anyone has two hours to spare. There is a lot of good info concerning this topic from a recent show on The Grass Factor:
> 
> 
> 
> ...


Nice. I will give this a watch.

This is the reason why I initially posed the question, by the way.

https://www.gardenerspantry.ca/images/phil/humicpowderapplication.pdf

Note the section on "Preplant In-Furrow, Sidedress and Foliar Applications"

Obviously just because a manufacturer gives a foliar application rate doesn't mean there's any benefit.


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