# Foliar Application During Grow-In



## Movingshrub (Jun 12, 2017)

I don't know if this fits into soil fertility or general.

I almost want to put it into my sprigging thread but it *could* apply to cool season as well even though vegetative propagation via sprigs or plugs seem way less common.

I know I am not the only one who has, or will, established their lawn by vegetative propagation.

When I planted via stolonizing in 2017, I followed basic guidance from Univ of TN to put down 1lb of nitrogen, via fast release fert, weekly, for three weeks, followed by an all purpose (1lb of N rate as well) the fourth week, and then to repeat until grow-in was complete. I'm a bit ashamed to admit this thought didn't cross my mind until my second stolonizing project - Why am I applying so much granular fertilizer if the plant doesn't have roots yet?

I'm making some assumptions here, and if these are wrong, my theory breaks down.

I assume that the nutrients available to the plant are what it had stored before being harvested, whatever can be absorbed from the air, and whatever is applied via foliar application, rain, or irrigation.

I assume that the plant is not able to absorb nutrients from the soil until it puts down roots. I am entertaining the possibility that the plant is able to absorb some nutrients from the soil via physical contact of the stolon to the sand or soil but I am also assuming this is an insufficient short-term method of obtaining nutrients from the soil.

I assume is that the plant is able to put down roots based on whatever nutrients it contained prior to harvesting so long as it doesn't dry out, and that eventually the plant would deplete these nutrients if not able to put down roots successfully.

My hypothesis is that the rate of establishment will increase with foliar supplementation of nutrients, so that the plant is no longer hamstrung by lack of a root system, specifically during grow-in of sprigged or stolonized bermuda or zoysiagrass. Part of this convo picked up in my stolonizing thread at this point https://thelawnforum.com/viewtopic.php?f=2&t=421&start=200#p73528

My primary assumption - I assume that all other limiting variables - sunlight, temperature, and water, are not impairing the grow-in and that the limiting variable is nutrient availability.

To use a metaphor, imagine holding your breath and swimming under water. You can survive on the oxygen you inhaled but eventually that's going to run out. So, you can either surface and take another breath (equivalent of plant putting down roots), you can expire/drown, which is the least appealing option when I go swimming, or you can use a scuba tank (equivalent of foliar supplemental fertilizer).

Now that those are all out of the way, to my questions.

At what point after harvesting does the plant start to run out of which nutrients?
What nutrients does the plant need, and when does it need them? How is the answer different for bermudagrass vs zoysiagrass?
How long does it take for the plant to absorb those limiting nutrients after application?
Does the nutrient applied need to breakdown/be processed in any capacity prior to absorption?
Does the plant absorb different version in a way that's more beneficial or harmful to the plant, ie, does it matter whether I apply ammonium, nitrate, or urea as the N source? 
Is it better to apply during a particular part of the day to increase uptake? 
Is there a benefit to including a surfactant when applying foliar fertilizer?
Do the answers to any of the above questions, change throughout the grow-in process?
What impact, if any, is there to rate of establishment?
Will turfgrass established by seed benefit at all by a foliar app since the seed is trying to put down roots immediately?
If foliar application results in lower quantity of fert applied, will this result in a cost savings to the grower?

I'd love to hear thoughts, comments, criticisms of this idea.

Also, below are some different articles that seem to suggest my idea is bad or at least has limited application.

https://sportsturfonline.com/2017/07/18/maintaining-nutrition-while-growing-in-bermudagrass/
Same author as Univ of TN sprigging document

https://turf.arizona.edu/ccps101.htm

http://archive.lib.msu.edu/tic/tgtre/article/2000jul11.pdf
Some quotes - Foliar fertlization is not very efficient. Uptake by leaves is much less than that by roots although this can vary depending on the nutrient status of the foliage...Foliar feeding would never be recommended as a general fertilization strategy. Foliar applications do have a place for providing some micronutrients when a quick response is desired.

http://www.usga.org/course-care/how-efficient-are-foliar-applied-nitrogen-applications-21474860541.html
"Adjuvants did not provide enhanced uptake of urea-nitrogen. There also was no effect on uptake when tank mixing urea-nitrogen with turf care products such as chlorothalonil (fungicide),Primo Maxx(growth regulator), Renaissance (biostimulant), and Tracker (indicator dye) alone or in combination." I wonder if this changes with AN or AS nitrogen source.

http://gsrpdf.lib.msu.edu/ticpdf.py?file=/2000s/2003/031101.pdf "Birth of a putting green" Talks about spoon feeding N at lower but more frequent rates during establishment. 5 day rotation of 0.3-0.6lb of N per 1k of Ammonium Sulfate


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## thegrassfactor (Apr 12, 2017)

Movingshrub said:


> I don't know if this fits into soil fertility or general.
> 
> I almost want to put it into my sprigging thread but it *could* apply to cool season as well even though vegetative propagation via sprigs or plugs seem way less common.
> 
> ...


In an effort to survive, the plant taps into its carbohydrate storages - hence why the stolons are what's planted. the carbohydrates drive the production of roots. It's not going to produce a boat load of roots off its reserves, but it's enough to establish enough feeders to begin water uptake. Ultimately it's the water that plays a critical role in the establishment of the sprigs.



Movingshrub said:


> I assume that the plant is not able to absorb nutrients from the soil until it puts down roots. I am entertaining the possibility that the plant is able to absorb some nutrients from the soil via physical contact of the stolon to the sand or soil but I am also assuming this is an insufficient short-term method of obtaining nutrients from the soil.


Correct, the plant will not allow for much uptake via stolons and stems, but within days of sprigs being down, the production of feeder roots begins to happen. How long can bermuda truly survive without any water in the entirety of the plant? not for very long, so the most important function of the plant is to establish roots. That's what will happen first, so the water uptake can begin. If your nutrients are water soluble, that will happen quickly as well.



Movingshrub said:


> I assume is that the plant is able to put down roots based on whatever nutrients it contained prior to harvesting so long as it doesn't dry out, and that eventually the plant would deplete these nutrients if not able to put down roots successfully.
> 
> My hypothesis is that the rate of establishment will increase with foliar supplementation of nutrients, so that the plant is no longer hamstrung by lack of a root system, specifically during grow-in of sprigged or stolonized bermuda or zoysiagrass. Part of this convo picked up in my stolonizing thread at this point https://thelawnforum.com/viewtopic.php?f=2&t=421&start=200#p73528


It puts down roots based on carbohydrate storage, not so much the NPK values in the tissues. NPK plays roles in plant functions and efficiencies, but the plant can survive with fractions of available nutrients. The nutrients are nowhere near as important as water.

In an effort to conserve water, the plant will slow transpiration (cuticle thickening early into sprigging, therefore limiting foliar uptake to begin with) So even if applied foliarly, the uptake will likely be the same - through the roots. So i don't foresee any major difference between soil applied or foliar applied nutrient in the early part of sprigging. As the plant becomes more self suffcienct, new leaves are produced, then foliar uptake will be more efficient (new leaves have a lesser cuticle, more material can be absorbed.



Movingshrub said:


> To use a metaphor, imagine holding your breath and swimming under water. You can survive on the oxygen you inhaled but eventually that's going to run out. So, you can either surface and take another breath (equivalent of plant putting down roots), you can expire/drown, which is the least appealing option when I go swimming, or you can use a scuba tank (equivalent of foliar supplemental fertilizer).


i see your analogy, but I don't think this metaphor is fair. the production of roots will have to happen fast - very fast - or the bermuda will never make it because the plant will run out of water first. most soils contain a fraction of enough nitrogen to allow the plant to function. The tiniest of feeder roots that begins to uptake water, can also pull on that nitrogen freely existing in the soil.

So to recap, the presence of nitrogen is relatively unimportant compared to water. The recommendation to hammer it hammer it hammer it is because the tiny roots at the surface can't pull in a ton of it and it's very quickly out of the soil profile that the roots have access to. Those initial roots are pushed out not by the presence of nitrogen, but through stored energy in the plant. Once that is pushed out, water uptake and nitrogen uptake can occur, leading to more chlorophyll, leading to more photosynthesized energy, leading to more root development. But none of this can even occur if the water aspect fails. It's not that the plant has stored NPK, but rather it has stored carbohydrates. That's the energy that will allow the plant to survive and revegetate, not the NPK, which leads into the foliar vs soil debate. since the primary stress response will be water conservation, the plant will have diminished transpiration function (cuticle will decrease in swelling blocking pore spaces for nutrient penetration) ultimately slowing the plants ability to uptake nutrients foliarly. that being said, what is applied foliarly will still make it's way to the soil and be taken up there. urea in general is very inefficient. trials have shown worst case scenario 30-70% of urea is lost to the environment. so I would make the argument that it would require equal amounts of nitrogen, because nitrogen in and of itself is too mobile, not allowing enough time in the newly developed "root zone." As the sprigs begin to regularly produce new leaves, then the switch to foliar applications will up your efficiencies and reduce costs.


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## Greendoc (Mar 24, 2018)

@thegrassfactor Which is why I wait a week or two to let roots come out and leaves to show first. Because I can, application volumes are high as well. The most important thing is to water, water, and water some more. I want the area to look wet all day long for the first 14 days. I call this growing grass by hydroponics. If I have watered enough, I see roots and leaves. Time to start feeding.


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## cglarsen (Dec 28, 2018)

Can someone advise on a readily available soluble N-P-K?

For example, will a standard bag of 10-10-10 dissolve sufficiently in 25 gallons to spray? So far I applied a little starter fertilizer (granular) and have just been spraying urea weekly (0.2 lb N / M) on my rennovation project. I'd like to mix in a complete fertilizer with this program.


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## Greendoc (Mar 24, 2018)

20-20-20 soluble readily available from vendors that service nurseries, greenhouses and hydroponic growers. You will want to apply 1 lb per K per application.


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## cglarsen (Dec 28, 2018)

Greendoc said:


> 20-20-20 soluble readily available from vendors that service nurseries, greenhouses and hydroponic growers. You will want to apply 1 lb per K per application.


Thank you sir - I'll check and see what i can find.


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## Movingshrub (Jun 12, 2017)

@cglarsen https://www.domyown.com/southern-ag-202020-soluble-fertilizer-p-8943.html


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## Movingshrub (Jun 12, 2017)

@Greendoc @thegrassfactor @osuturfman @Ecks from Tex Any of you guys interested in offering grow-in spoon feeding input, particularly if it involves foliar application?

The big take away I got from the previous conversation on this thread was, water the F out of sprigs/stolons during grow-in, use a water soluble N source, and apply small amounts frequently, so as to promote the likelihood of N near the small roots, and to avoid run off by excess N application. My assumption is that AMS is better than urea, due to being available to the plant ASAP. Is there any value in applying both Calcium Nitrate and Ammonium Sulfate so as to get both Ammonium and Nitrate available?


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## Ecks from Tex (Apr 26, 2018)

Movingshrub said:


> @Greendoc @thegrassfactor @osuturfman @Ecks from Tex Any of you guys interested in offering grow-in spoon feeding input, particularly if it involves foliar application?
> 
> The big take away I got from the previous conversation on this thread was, water the F out of sprigs/stolons during grow-in, use a water soluble N source, and apply small amounts frequently, so as to promote the likelihood of N near the small roots, and to avoid run off by excess N application. My assumption is that AMS is better than urea, due to being available to the plant ASAP. Is there any value in applying both Calcium Nitrate and Ammonium Sulfate so as to get both Ammonium and Nitrate available?


I treat that scenario exactly like I treat my annual flowers. Spoon feed through a backpack sprayer to get nutrients to the struggling root systems and higher foliar uptake. And I have always liked a soluble 20-20-20 like Greendoc says; its the professional blend so to speak. Peters Professional makes the original, but I use a knockoff from Southern Ag. I would look for something that definitely has a blend of the nitrate and ammonium.


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## Greendoc (Mar 24, 2018)

If you did not need P, I would be applying Calcium Nitrate and Potassium Nitrate 1-1 ratio of those at 0.25 lb N per 1000 sq ft. Those can be mixed without causing a brick to form. If you did not need even the K, straight Calcium Nitrate at 0.25 lb per 1000 sq ft is another option. If I remember rightly, your soil needed Calcium.


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## Movingshrub (Jun 12, 2017)

Greendoc said:


> If you did not need P, I would be applying Calcium Nitrate and Potassium Nitrate 1-1 ratio of those at 0.25 lb N per 1000 sq ft. Those can be mixed without causing a brick to form. If you did not need even the K, straight Calcium Nitrate at 0.25 lb per 1000 sq ft is another option. If I remember rightly, your soil needed Calcium.


Any particular suggestion on that frequency? Ever three days? Five days?


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## Greendoc (Mar 24, 2018)

7 days


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## Movingshrub (Jun 12, 2017)

Regarding nitrogen,

Does the plant care whether the nitrogen is in the form of NH4 versus NO3? Whether by foliar absorption or root uptake, is the plant more likely to absorb N during non-drought conditions?


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## adgattoni (Oct 3, 2017)

Movingshrub said:


> @cglarsen https://www.domyown.com/southern-ag-202020-soluble-fertilizer-p-8943.html


Anyone found anything a bit more affordable? I can't seem to find it in stores and everything online seems to be about $50/25lb bag ($10/lb NPK).


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## Movingshrub (Jun 12, 2017)

adgattoni said:


> Movingshrub said:
> 
> 
> > @cglarsen https://www.domyown.com/southern-ag-202020-soluble-fertilizer-p-8943.html
> ...


My best price was my local co-op.

Also, there is this http://www.growers-inc.com/peters-20-20-20-water-soluble-fertilizer-25/


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## sanders4617 (Jul 9, 2018)

adgattoni said:


> Movingshrub said:
> 
> 
> > @cglarsen https://www.domyown.com/southern-ag-202020-soluble-fertilizer-p-8943.html
> ...


I got a bag of 20-20-20 (25lb) from SiteOne... ProSol - was $36 if I remember correctly.

https://www.siteone.com/p/241187

That is the link.. Actually showing $31 for me.


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