# Boron test plot, possibly boronic?



## dwaugh (Aug 25, 2020)

So I got my soil report back and I'm low on Boron. From reading the forum, it seems the general consensus is that given boron's toxicity at relatively low levels, it's best not to mess with it. Seeing as I have a really crappy lawn, I thought it would be fun to try and experiment and see what happens if I add some to a test strip. I was thinking maybe 1X15 or 1X20 feet. I was hoping people could check my math on the rates to apply (math is not a strong point for me….)

So my soil report shows I have 0.5 ppm and "optimal" is 1.7-2.6 ppm. I found some other website that suggested 1.2 ppm was reasonable. That's a lower number (1.2 ppm) so I will go for that, mostly I want to see if my grass responds at all. So I want to add 0.7 ppm boron.
0.7 ppm =1.4lb/acre
=0.032lb/1000 square feet
If I use borax which is 11% boron, I need:
0.291lb/1000 square feet
=14.52 grams/1000 square feet
=0.01452/square foot
So for 15 square feet I need 0.217 grams, or for 20 square feet 0.2904 grams

Does that math look right? I would dissolve the borax in one gallon of water and spray the grass, and then water it in.
Yes, I realize I might kill the grass


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## dwaugh (Aug 25, 2020)

I got a test plot set up, it ended up being 31 feet long (by 1 foot) to make it easier to tie into hard points. So at 31 square feet, I think I need 0.45 grams...


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## dicko1 (Oct 25, 2019)

Borax isnt all that toxic.
It's LD50 (50% lethal dose) is 2.6g/kg in rats when ingested. Table salt's LD50 is 3000 g/kg in rats. So its just slightly more toxic than common salt.

MSDS for borax https://fscimage.fishersci.com/msds/21010.htm
MSDS for NaCl https://fscimage.fishersci.com/msds/21105.htm

A teaspoon of Borax is about 9 grams you're using .45 grams or roughly 1/20th of a teaspoon. You're using such a small amount I wouldnt worry about killing anything.


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## dwaugh (Aug 25, 2020)

Well, not sure if my math was correct, but I wanted to get it down. I don't want to leave the string up, as I'm prepared I might kill the grass, but I not ok with tripping the older dog and having her get hurt. How would I even explain that to the vet "oh, I set up a boron test plot in my yard....."

I should have gone into work and used a better scale, but this is how much I got for 0.45 grams. I measured some out on something with a smaller tare weight and got a similar amount (visually)


I dissolved that in hot tap water and then added that to one gallon of water in a sprayer. It actually took awhile to spray it all. After the spraying I watered it in, and will go out now and add more water (I didn't want to cause too much run off out of the test strip). 


If my math was wrong, hopefully I under applied


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## g-man (Jun 15, 2017)

What response do you expect?


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## dwaugh (Aug 25, 2020)

g-man said:


> What response do you expect?


My guess is nothing, or possible some short-term damage. I have no real basis for the following.... I would guess boron deficiency is real, as is boron toxicity is a bigger problem. If testing for it was meaningless I would assume people would not test for it and give optimum ranges. On the other hand, if it was the secret to perfect grass, people would be spending a lot more time talking about it. So my guess is that it's a non-issue, and I don't expect much to happen, but it seemed worth testing. Assuming my math is correct, and it could well be off, I think I applied enough that if my grass was truly deficient, there would be some reaction.


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## g-man (Jun 15, 2017)

Most of these soil test are testing a standard items regardless of the crop. If you are growing corn, then yes you might be more concerned about boron levels. In turf, I've seen it fluctuate. You can see my soil test results over the years and it goes up/down, but I've never applied any. We are talking about something in the 1ppm range. Sampling variability will play a big factor.

Hence why I just don't worry about. Unless you are seeing something in your turf that we can't explain via nitrogen, phosphorus, potassium, iron, sulfur; then we can do a deeper dive into the micros.

I think you can safely do 2tablespoon/ksqft of borax.


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## ken-n-nancy (Jul 25, 2017)

I just want to mention one thing that may cause different results than you would expect... The soil tests are just that -- a test of the *soil*.

When you converted from 0.7ppm to 1.4lb/acre, the 1:2 calculation presumes an "acre furrow slice" of soil, which is a depth of about 6.7 inches of soil for an acre. An "acre furrow slice" of soil weighs about 2,000,000 pounds, so that is where the 1:2 conversion for ppm to lb/acre comes from.

However, the 0.045 grams of boron that you're adding isn't getting evenly distributted in the top 6.7 inches of soil in the 31 square feet you covered, but is instead being applied partly as a foliar application by spraying it onto the grass in the test plot. Well, except for the fact that 1 gallon on 31 square feet is a *lot* of water, so the application probably isn't even mostly foliar, as that application rate is more of a soil drench. Plus, your watering it in afterwards was probably intended to wash the boron off the leaves into the soil, too.

In any case, using your application approach the amount of boron which becomes readily available to the plant, and indeed ends up in plant tissue, is likely to be much higher than what would normally be the case if there were an additional 0.7ppm of boron in the soil.

That said, if the grass doesn't suffer any adverse effects, then it seems that your method of application could be safe. However, I think it will deliver far more boron to the plant, at least in the short term, via the partial foliar application, than if the borax were distributed with a granular fertilizer.


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## g-man (Jun 15, 2017)

I forgot to add, borax can be use as a weed killer. It is not the greatest and can kill your lawn, via foliar.


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## dwaugh (Aug 25, 2020)

@g-man and @ken-n-nancy I admit, it's likely this was a very poorly thought out experiment.


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## ken-n-nancy (Jul 25, 2017)

dwaugh said:


> @g-man and @ken-n-nancy I admit, it's likely this was a very poorly thought out experiment.


Hey, I don't think you have anything to be ashamed about. On the contrary, I think you have shown initiative and interest in learning something! It's not like any of us is trying to get a research study published in a turf journal!

I commend you for doing an experiment in somewhat controlled circumstances and having the courage to post about it!


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## g-man (Jun 15, 2017)

Test, experiment and do all you want on your yard. Just be ready to explain to the wife the section of mud if it doesn't go as planned.


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## Ridgerunner (May 16, 2017)

That photo of 4 grams or 0.45 grams of Borax? If it's 0.45g of Borax that's 0.049g of B, not 0.45g of B.
I think you're a decimal off on your calculations. I believe you applied 1/10 of the amount you intended to. That may be a good thing, as you could apply the rest via spoon feeding it by adding the same amount 9 more times. Test next year and see what change in B there is.


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## dwaugh (Aug 25, 2020)

Ridgerunner said:


> That photo of 4 grams or 0.45 grams of Borax? If it's 0.45g of Borax that's 0.049g of B, not 0.45g of B.
> I think you're a decimal off on your calculations. I believe you applied 1/10 of the amount you intended to. That may be a good thing, as you could apply the rest via spoon feeding it by adding the same amount 9 more times. Test next year and see what change in B there is.


I'll check my math again. I tried to take into account the borax being 11% boron, but my could be wrong. It was 0.45g that I added.


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## Ridgerunner (May 16, 2017)

1.4 lbs of B/acre divided by 43.56 = 0.032 lbs of B/M (thousand square feet).
0.032 lbs/M times 453 (grams in one pound) = 14.5g of B/M.
14.5g divided by .11 (calculating of the amount of 11% B content Borax needed) = 131.8g of Borax/M or 0.1318g of Borax per square foot.
To raise B levels by 0.7 ppm in approximately 17 cubic feet of soil (31 square feet to an acre furrow slice depth), 4.08g of Borax would be required.


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## dwaugh (Aug 25, 2020)

Ridgerunner said:


> 1.4 lbs of B/acre divided by 43.56 = 0.032 lbs of B/M (thousand square feet).
> 0.032 lbs/M times 453 (grams in one pound) = 14.5g of B/M.
> 14.5g divided by .11 (calculating of the amount of 11% B content Borax needed) = 131.8g of Borax/M or 0.1318g of Borax per square foot.
> To raise B levels by 0.7 ppm in approximately 17 cubic feet of soil (31 square feet to an acre furrow slice depth), 4.08g of Borax would be required.


I think you are right, I did the math again and got what you just posted.


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## dwaugh (Aug 25, 2020)

On the plus side, we have demonstrated that I'm bad at math and thanks to @Ridgerunner the importance of peer review.

@ken-n-nancy made a good point:


> In any case, using your application approach the amount of boron which becomes readily available to the plant, and indeed ends up in plant tissue, is likely to be much higher than what would normally be the case if there were an additional 0.7ppm of boron in the soil.


If the grass was truly deficient in boron, which seem unlikely, the small amount I added could help it..... I think the thing to do now is let this sit for a week or so and see what happens.


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## dwaugh (Aug 25, 2020)

It's been a week after the lower than planned application of boron.....

Below you can see nothing visibly changed in the test strip after 7 days.


A closeup (below) with the string added back for a respray.



Given comments by @Ridgerunner and @ken-n-nancy it's probably not best to apply the full dose all at once, and luckily due to my math error that didn't happen. So the original intent was to apply 4.08grams to 31 square feet, but I only applied 0.45 grams, so I'm 3.63 short. I figured I would add 1.5grams, which I did today (in one gallon water, watered in via two 5 minute hose sprays to wash it off the blades, spaced 20 minutes apart to avoid runoff into the surround grass).


I can't find the NIST traceable calibration for the scale 

I guess I will let this sit for a year and see what happens. My guess is nothing.


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## ken-n-nancy (Jul 25, 2017)

Curious to see how this turns out.

Ironically, I just bought a box of 20 Mule Team Borax at the store today -- the box I bought back in 2014 and have been applying to our lawn little by little is just about gone...


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## dwaugh (Aug 25, 2020)

ken-n-nancy said:


> Curious to see how this turns out.
> 
> Ironically, I just bought a box of 20 Mule Team Borax at the store today -- the box I bought back in 2014 and have been applying to our lawn little by little is just about gone...


Just don't use my math 

I will have to pull the stakes up, but I have enough measurements to locate the strip again, it should be dramatic enough (if anything occurs) to see if anything happens (appearance wise), and I would guess the non-visual stuff like roots growth, general health etc. would show up in winter and summer stress periods.

If nothing else, the box suggests all kinds of other uses


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## dwaugh (Aug 25, 2020)

For the 0.2 people watching this thread. There has been no visible effect.


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## ionicatoms (Mar 8, 2020)

Thanks for following up.


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## Ridgerunner (May 16, 2017)

ionicatoms said:


> Thanks for following up.


 :thumbup:


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## Ridgerunner (May 16, 2017)

So any next step? Are you planning to increase the app significantly?


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## dwaugh (Aug 25, 2020)

Ridgerunner said:


> So any next step? Are you planning to increase the app significantly?


Well, working under the assumption that if my grass was actually deficient (which I think is unlikely), I should wait and watch for a year and see if anything happens. Even though I am not looking at clippings yield or root growth, times of stress (which this is not) should show something (if in deficit). Although it tempting to keeping upping the dose until something happens  I think the Dwaugh Turfgrass Experimental Station will be moving on to understanding and testing for soil compaction.


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## Deadlawn (Sep 8, 2020)

Interesting experiment. However, in the grand scheme of things, boron as well as other micro nutrients are easily and most safely corrected by increasing organic matter. Or to put it another way, if you are deficient in boron, you are probably deficient in organic matter.


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## dwaugh (Aug 25, 2020)

Deadlawn said:


> Interesting experiment. However, in the grand scheme of things, boron as well as other micro nutrients are easily and most safely corrected by increasing organic matter. Or to put it another way, if you are deficient in boron, you are probably deficient in organic matter.


My goal in this case was/is to test if I am actually lacking boron (I'm guessing I'm not really), so adding organics would introduce other variables.


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## Deadlawn (Sep 8, 2020)

dwaugh said:


> Deadlawn said:
> 
> 
> > Interesting experiment. However, in the grand scheme of things, boron as well as other micro nutrients are easily and most safely corrected by increasing organic matter. Or to put it another way, if you are deficient in boron, you are probably deficient in organic matter.
> ...


I may have misled you. When I said organic matter, I am talking about things like compost, rotted plant matter, etc., not organic fertilizers. If you are low in boron, you are most likely low in organic matter (non mineral soil matter). I'm pretty sure a compost topdressing or compost tea application would only help.


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## dwaugh (Aug 25, 2020)

Deadlawn said:


> I may have misled you. When I said organic matter, I am talking about things like compost, rotted plant matter, etc., not organic fertilizers. If you are low in boron, you are most likely low in organic matter (non mineral soil matter). I'm pretty sure a compost topdressing or compost tea application would only help.


I figured you meant stuff like compost, and agree it could certainly help my sad lawn, but it would not have worked for my "experiment". Now I'm all for running a compost test plot


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## Deadlawn (Sep 8, 2020)

dwaugh said:


> Deadlawn said:
> 
> 
> > I may have misled you. When I said organic matter, I am talking about things like compost, rotted plant matter, etc., not organic fertilizers. If you are low in boron, you are most likely low in organic matter (non mineral soil matter). I'm pretty sure a compost topdressing or compost tea application would only help.
> ...


Just get a pile of bulk compost and spread it at 1/2 to 1 inch over your lawn as long as most of the blades are sticking up through it. Prepare to mow more often after that!

BTW, looking at the pics of your lawn, it doesn't look too "sad" to me, but then again I'm not too fussy.


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