how to convert pounds to an acre down to ounces per square feet?

I am trying to convert '4# borax per acre' to x amount per 10 square feet to spread under my peach tree.

I know I could ask google or something and get a quick answer but I would like to know the steps in order to get to the answer.

I'm assuming it's tablespoons by the time it's downsized to a smaller area.

Just so I don't go with my usual 'maybe a handful' method I thought maybe someone here likes math and can help me see the process.

...and I did try, there are 43,560 sq ft in an acre, 10,890 sq ft to a quarter acre, so that's down to 1# borax.
then I got lost.

thanks😊

and a cup of borax apparently weighs 7.2 ounces.
I'm hoping to end up with spoon measurements though.

Seems to me, I would start with how many square feet are in an acre which I was told is 2.2956 square feet.

Then divide the amount of Borax by 2.2956.

Once you get that amount that can be divided into cups or tablespoons, teaspoons, etc.

I hope that some math wizard will say yes that is right.

Sometimes I'm so grateful for the metric system...

4lb is approximately 1.8kg

An acre is 4047 square metres

So 1800/4047 is 0.44, so that's the number of grams you need per square metre. Which isn't far from 10 square feet, assuming you don't really mean 10ft x 10ft.

I'm guessing a teaspoon would weigh around 5g, so you'd probably only need fraction of a teaspoon around your tree.

Or maybe I'd just wash my glassware with some borax to shine it up a bit then sploosh the greywater around the tree.

Edited because some days I'm a total dumbass...

Here's the math...


  4 lbs              16 oz/lb                 64 oz
-----------   *  -----------------     =    ------------  
 1 acre         43,560 sf/ac          43,560sf

=>

  64               x
---------  =  ----------
43560          10

=>

64 / 43560 * 10 = 0.015 oz per 10sf

that's not much...fraction of a tsp, probably.

Easy in metric system:
4 lbs = 1.8 kg
1 acre = 4047 m2
1.8 kg/4047 m2 = 0.44 g/m2
10 sq ft is around 0.9 m2 so for this area you would use 0.9*0.44 g = 0.4 g

Specific gravity of borax is around 1.8 g/cm3 so 0.4 g  would be around 0.22 cm3. Measuring spoon has 5 cm3. Precise 0.22 cm3 would be difficult to scoop with a tiny measuring spoon. I face these problems when preparing test enamels for ceramics. In your case I would use 1/8 measuring spoon (0.625 cm3) per 3 trees.

For plants boric acid should be used, as borax has lower boron bioavailability.
When I was using boric acid for my pistachios I dilluted half a spoon in a 5 gal bucket and used it for watering one tree.

thank you all!!!
I knew I could count on  answers from real folks😊
Who needs google!

The 10 square feet per tree is really a 3 foot circle of bare dirt around my tree to try to deter peach tree borer larvae...squared off to 3 foot by 3 foot is 9 square feet but for my math I thought calling it 10 square feet would be close enough and I'm not up to figuring out square feet of a circle.

I'm happy sprinkling a scant teaspoon of borax now.

Judith Browning wrote:
The 10 square feet per tree is really a 3 foot circle of bare dirt around my tree to try to deter peach tree borer larvae...squared off to 3 foot by 3 foot is 9 square feet but for my math I thought calling it 10 square feet would be close enough and I'm not up to figuring out square feet of a circle.

You're welcome! Bonus formula for you - the area of the circle is pi times the radius squared 3.14*(1.5^2) - so it's roughly 7sf

I think the one lesson I really learned from all this is why they do NOT recommend that you use borax in your grey water system. A regular dose of just a teaspoon or two is soon going to add up in a small garden!

Benedict Bosco wrote:

Judith Browning wrote:
The 10 square feet per tree is really a 3 foot circle of bare dirt around my tree to try to deter peach tree borer larvae...squared off to 3 foot by 3 foot is 9 square feet but for my math I thought calling it 10 square feet would be close enough and I'm not up to figuring out square feet of a circle.

You're welcome! Bonus formula for you - the area of the circle is pi times the radius squared 3.14*(1.5^2) - so it's roughly 7sf

Benedict,
thanks for that formula...
so 3 sq ft less than my really rough estimate...might be using a half teaspoon.

Peaches can use the boron though.

Cristobal, I do have boric acid so could use it instead.....there are several peach trees so can experiment.

Burra Maluca wrote:I think the one lesson I really learned from all this is why they do NOT recommend that you use borax in your grey water system. A regular dose of just a teaspoon or two is soon going to add up in a small garden!

yeah, probably not good at all in a grey water system.
We have it on hand to spray lumber as insect protection...very concentrated compared to soil amendments.

for the peaches I think I'l mix with water to apply as I 'm not sure how I could sprinkle that tiny amount evenly?