Weight of No-Till Bed

Hello again ICmag. Old grower, new account for legal distinction.


Question:

For those of you with organic/no-till beds indoors, what is the weight of those beds at their maximum?




In the past, I used 4'x8'x10" beds sitting on a raised platform above the floor. They used about 1 cubic yard of soil each and total weight was never an issue for those particular platforms. However, in this particular buildout, the business' production style is dependent on the maximum weight.

After years of growing organic beds, you'd think this information would be readily available but I have never paid attention to the physical weight of a the rootzone at its maximum -- typically the process involves building the bed and filling it.




By the Math:

Let's assume that each bed can hold 1 cubic yard of soil. Starting with an extreme like planting into 100% worm castings tells me that one of those beds loaded with plants, blumats, etc, is going to weigh about 1,300lbs-1,400lbs without watering (assuming worm castings weight 1,200lbs/cuyd).

If worm castings can hold appx 3 times their weight in water, we would be looking at around 4,000 lbs per bed.

However, the bed wont be made of 100% worm castings. The mix will be lighter with more air-filled pore space from char, perlite, volcanic rock, etc.

If a typical peat mix weighs about 1lb/gallon and I add 20% castings that weigh 7oz/cup, the same gallon will then weigh about 2.5lbs. This soilmix at 1 cubic yard = 500lbs. Holding 3x its weight in water puts the maximum capacity at 1,500lbs.




What would help:

I fell into a rabbit hole yesterday trying to figure out bulk density of organic media, looks like there's some disagreement on how to gather those measurements. But now I'm unsure of how to calibrate this calculation. Can you guys tell me if I'm on the right track?

Would anyone know how much their own fully-loaded beds weigh and you be willing to share specifications?



Thank you for any help!
Canis

Do you have your mix already made in a smaller volume? If you have that wet some to saturation point then weigh it out and do your calculation based on that weight (1 gallon, 2 gallons) there are good conversion charts from sun gro how many points per cubic foot so your math would be really easy to ball pack a reasonably accurate number.

Limeygreen said:

Do you have your mix already made in a smaller volume? If you have that wet some to saturation point then weigh it out and do your calculation based on that weight (1 gallon, 2 gallons) there are good conversion charts from sun gro how many points per cubic foot so your math would be really easy to ball pack a reasonably accurate number.

Click to expand...

Thanks for the reply! Yeah that was my thought too but unfortunately, I do not. Ultimately, it will be my plan once the investors decide on the location.

Just trying to get ahead of the wave. Thank you!

CanisMinor, the problem as I see it is in the unknown values of your other inputs stated earlier

The mix will be lighter with more air-filled pore space from char, perlite, volcanic rock, etc.

Click to expand...

Not only the quantity of each but equally important would be the source of each input-
scoria/volcanic rock for example.

Different sources of volcanic rock have different characteristics causing them to weigh very differently

Once you are able to define the weight of each specific input, I believe you will be one step closer to achieving your goal

1 yard of soil weighs between 2000-2500lbs depending on it's makeup.

Water weighs 8.34 lbs per gallon.

Your amendments are weighed going in so you should have that number.

Now weigh a smaller amount of soil. Say a gallon.

Now water that gallon of soil you weighed until it is to the point it would be if it was growing a plant. Weigh what's left of gallon of water you watered with.

Subtract that from 8.34.

Add together the weight of the gallon of soil plus the amount of water it took to wet it, and multiply by 202 ( gallons in a yard).

You should be able to get very close that weigh or ballpark it easy enough.

Rico Swazi said:

CanisMinor, the problem as I see it is in the unknown values of your other inputs stated earlier
Not only the quantity of each but equally important would be the source of each input-
scoria/volcanic rock for example.

Different sources of volcanic rock have different characteristics causing them to weigh very differently

Once you are able to define the weight of each specific input, I believe you will be one step closer to achieving your goal

Click to expand...

Rico, yes, I agree -- the build/production practices depend on a specific weight limit. It's a new challenge for me so thank you for the feedback!

Lester Beans said:

1 yard of soil weighs between 2000-2500lbs depending on it's makeup.

Water weighs 8.34 lbs per gallon.

Your amendments are weighed going in so you should have that number.

Now weigh a smaller amount of soil. Say a gallon.

Now water that gallon of soil you weighed until it is to the point it would be if it was growing a plant. Weigh what's left of gallon of water you watered with.

Subtract that from 8.34.

Add together the weight of the gallon of soil plus the amount of water it took to wet it, and multiply by 202 ( gallons in a yard).

You should be able to get very close that weigh or ballpark it easy enough.

Click to expand...

Lester, I like this method. There might just be enough media/compost around the house to make mock-soil for an approximate weight. Thank you!

Let me give these a try and get back to you guys.

Rico, yes, I agree -- the build/production practices depend on a specific weight limit.

Click to expand...

why don't you use the same build/design/production practices you have done in the past?
Were the old beds made out of wood ? What will be the material used for the new beds?

In the past, I used 4'x8'x10" beds sitting on a raised platform above the floor. They used about 1 cubic yard of soil each and total weight was never an issue for those particular platforms. However, in this particular buildout, the business' production style is dependent on the maximum weight.

Click to expand...

One would think if weight wasn't an issue in the past you are good to go rereviously built beds.
Pics of beds from the past would help as someone may see a structural flaw and save you some grief in future builds.

I honestly believe you are spinning your wheels trying to cobble together a mock soil .


The weight of bulk materials you plan on using for the actual build needs to be addressed. Accept no substitutes.

On recommendation, required materials were purchased, mixed, added to pot, and watered to saturation. After allowing the pot to sit overnight, I measured out 1 gallon, weighed, rounded up, and multiplied to reach the qty needed. Ended up just under 1,500 lbs for one cubic yard. Thank you guys for encouraging me to approach it this way.

Rico Swazi said:

why don't you use the same build/design/production practices you have done in the past?
Were the old beds made out of wood ? What will be the material used for the new beds?
One would think if weight wasn't an issue in the past you are good to go rereviously built beds.
Pics of beds from the past would help as someone may see a structural flaw and save you some grief in future builds.

I honestly believe you are spinning your wheels trying to cobble together a mock soil .


The weight of bulk materials you plan on using for the actual build needs to be addressed. Accept no substitutes.

Click to expand...

Hey Rico, thank you!

Yeah agreed and the reason for new info is that it's a new grow i.e. pre-buildout. We're looking at ways to incorporate vertical growing methods into no-till production and I'm seeing no reason it's impossible. Any thoughts here?

Through some searching online clear water is 1682.3 lbs per yard. Filling the beds with coco coir the most expensive and fluffiest media/amendment would give a max weight of slightly less than being filled with water. Mineral components like clay or stone can approach 3000 lbs per yard saturated. It would be wise to weigh one of the soil beds filled. The "no-till" soil you mention might have a density somewhere in between coco and gravel. Compost will continue to shrink as it decomposes.