Small wicking box experiment

Plantoid, thanks for the info on the wicking, but esp the probe. It explains past failure/false readings. I just quit using them, even though I kept it in storage. The internet wasn't around or in it's birthing process for quick solutions.
Thank you again.

Yolos, interesting find.   At various times, he's used wicking beds as water storage in areas of intermittent drought, as a means to create healthy soil from barren dirt, and to remove CO₂ from the atmosphere.  He tends to go off on tangents from the topic titles, which makes it hard to find answers.

Interestingly, he recommends using organic matter rather than stones in the 'tub'.  He feels that the anaerobic decomposition creates a tea that is full of fungi that benefits the soil.  There was no research data provided to support his opinion.  

The more I learn, the more I learn how much more I don't know!    

boffer wrote:

The more I learn, the more I learn how much more I don't know!    

Yup.   

boffer wrote:Yolos, interesting find.   At various times, he's used wicking beds as water storage in areas of intermittent drought, as a means to create healthy soil from barren dirt, and to remove CO₂ from the atmosphere.  He tends to go off on tangents from the topic titles, which makes it hard to find answers.

Interestingly, he recommends using organic matter rather than stones in the 'tub'.  He feels that the anaerobic decomposition creates a tea that is full of fungi that benefits the soil.  There was no research data provided to support his opinion.  

The more I learn, the more I learn how much more I don't know!    

The problem with using the organic matter as the wick is that it can bring the water up too high and it will cause the plants  hair roots & tap roots to rot . You have to do some careful experimenting with your growth medium & the water levels as not all plants like their " feet "  in too wet a ground .


In fact it seems most plants like it a tad towards the dry side then a decent wetting and drying off a bit.. This might be something to do with the plant cell walls getting stressed and therefore becoming stronger and more self supporting of the plant.

One Week Update:

The chard plants are looking healthy.


On the second day, the water level dropped to 2 inches, and has stayed there since.  The surface of the  MM is beginning to dry out.


I didn't expect to see the roots growing through the muslin to reach water.

hey Boffer this is pretty neat!

reminds me of hydroponics.....  

I look forward to see how this goes.....I hope you have enough winter veggies to eat so you don't consume the project   

happy gardening
rose

Boffer, thanks again for sharing this experiment. 

I see the roots have penetrated that muslin -- I'm thinking muslin might be woven loosely enough to the point of easy penetration for a root. Do you think if you used a tighter burlap, or even something like weed fabric, you may not have had that problem? Do you have any worries of root rot?

It looks like this experiment is going somewhat well though. Would you say the bottom 50% of the soil is moist? Bottom 60%? 70%? Or in other words, how much percent of the top soil is dry -- the top 20%, 30%, 40%? And have you been going back over the top and adding any water?

Regarding planting different crops in wicking boxes, a few considerations:

Roots will always seek water, so if the water is not in the growing medium, often the roots will go to the water.

Some plants have deep root systems, some have quite shallow root systems. If the top portion of the growing medium is going to be dry, the plants with the shallow roots may suffer.

Good point camprn! You wouldn't happen to be able to name a few types of vegetables with more shallow root systems off the top of your head, would you?

I'm thinking for people who do have wicking beds/boxes, they should be conscious of which beds/boxes contain the vegetables with the more shallow root systems, in order to keep a closer eye on the top portion of the soil in case they'd have to sprinkle water from above more often.

One might even want to go as far as designating "deep-root wicking beds" and "shallow-root wicking beds," where instead of using 6 inches of MM in the "shallow-root wicking bed," one could use 4 inches of MM in hopes of a more uniform dispersion of moisture via capillary action/wicking. Does that sound feasible? I'm quite the newbie, so I'm just trying to feel things out a bit, I have no clue as to the validity of my ideas!?

Week 2 update:





The water level in the gravel has dropped to the 3¼ mark.  The MM is bone dry down to 5 inches, and being generous, it's a little dampish at the muslin.  

I haven't added any water to the system.  At this point, I don't see any indication that the water in the gravel is keeping the  MM saturated.  The longest roots are following the water level.

I'm thinking that I'll let the water level drop to 4-5 inches before re-filling the reservoir.  Will a full reservoir drown the roots that are in the gravel?  Will the plants   begin showing signs of nutrient deficiency since the MM is dry?

tumtumsback wrote: I'm thinking for people who do have wicking beds/boxes, they should be conscious of which beds/boxes contain the vegetables with the more shallow root systems, in order to keep a closer eye on the top portion of the soil in case they'd have to sprinkle water from above more often.

One might even want to go as far as designating "deep-root wicking beds" and "shallow-root wicking beds," where instead of using 6 inches of MM in the "shallow-root wicking bed," one could use 4 inches of MM in hopes of a more uniform dispersion of moisture via capillary action/wicking. Does that sound feasible?

Sounds like TMW for me!

Boffer,

Just out of curiosity, why would you let the water drop down so far before refilling? I'm thinking that if your water level has dropped 3 inches in two weeks, that's about a 1/4 inch a day. In a setting like yours, I would probably want to top it off every 4 days, not letting the water level drop lower than an inch from the muslin. The farther away the water gets from the muslin, the harder it would be to initiate the capillary action.

I'm thinking that when I go to do my wicking beds, I am going to want to keep the water level as close to the muslin (or in my case, weed mat) as possible at all times. Since the reservoir in my bed is going to be 4'x4'x9", my volume of water is going to be much greater than yours, which (I think) will make it so I won't have to water as often, plus I think I am going to be using a combination of black corrugated piping with pea gravel, which will make for a much greater volume of water underneath. So much of your water is being displaced by the rocks, which is making your water level disappear much quicker than in a setting with black corrugated piping..

Also, how much MM is there in that box, 5 inches? It seems like more... Also, how moist was the MM to begin with when you put it in the bucket? Also, since my beds are going to be outside, they will see the rain, which will help keep things a bit more moist (especially from the top) than in your experiment.

tumtumsback,

Purpose of this experiment: To observe first hand how water can wick upwards through gravel to keep the growing medium sufficiently damp for the plants in it.

Nominally, there's 6 inches of MM and 6 inches of gravel.  I've read that the gravel filled tub should be no deeper than 200-300 mm.  6 inches≈150mm.  

The MM was nearly saturated when I started.  I'm letting the water level drop in the reservoir to simulate an absentee gardener. If I have to baby-sit this system by keeping the tub topped off, then I'm being less efficient  than using a regular SFG box that is well-mulched, or a wicking box system that uses 'baskets'.

Boffer,   I read the link that Camprn posted here https://squarefoot.forumotion.com/t3068p60-sfg-wicking-boxes#182757
It says that gravel acts as a wicking agent.  So I wonder if the gravel you are using is working as a wicking agent.

Rocks /  gravel can hold a surprising amount of water.  At first glance, they just look solid.

yolos wrote:Boffer,   I read the link that Camprn posted here https://squarefoot.forumotion.com/t3068p60-sfg-wicking-boxes#182757
It says that gravel acts as a wicking agent.  So I wonder if the gravel you are using is working as a wicking agent.

It's definitely not wicking, so I must have defective gravel!   

I'm using what we call 'crushed rock' in the PNW.  I'll try to come up with some pea gravel and then start over.

boffer wrote:

 

It's definitely not wicking, so I must have defective gravel!   

   

boffer wrote:

yolos wrote:Boffer,   I read the link that Camprn posted here https://squarefoot.forumotion.com/t3068p60-sfg-wicking-boxes#182757
It says that gravel acts as a wicking agent.  So I wonder if the gravel you are using is working as a wicking agent.

It's definitely not wicking, so I must have defective gravel!   

I'm using what we call 'crushed rock' in the PNW.  I'll try to come up with some pea gravel and then start over.

Yolos, who said gravel was wicking?

I'm curious why folks that have wicking boxes just don't put actual wicks in them.      

camprn wrote:

boffer wrote:

yolos wrote:Boffer,   I read the link that Camprn posted here https://squarefoot.forumotion.com/t3068p60-sfg-wicking-boxes#182757
It says that gravel acts as a wicking agent.  So I wonder if the gravel you are using is working as a wicking agent.

It's definitely not wicking, so I must have defective gravel!   

I'm using what we call 'crushed rock' in the PNW.  I'll try to come up with some pea gravel and then start over.

Yolos, who said gravel was wicking?

I'm curious why folks that have wicking boxes just don't put actual wicks in them.      

Camprn, in the quote box is a link to a thread about wicking boxes.  In that thread you referred to this link -




http://www.resilience.org/stories/2011-05-31/bottom-diy-guide-wicking-beds

In this link the article mentioned gravel as a wicking agent.  At least that is how I interpreted the article.  Here is an excerpt from the article.

Reservoirs with Media
Most of the DIY sites for wicking beds focus on building beds that use media, a layer in between the soil and the water reservoir, as their wick. This is an easy and cheap way of supporting the soil on top of the reservoir. Gravel is the most common medium, but there are a number of materials that do the trick. Here's a good DIY blog on media wicking beds.


I am not sure why they are not using wicks but I think it is because of the size of the beds and if gravel really does wick it is spread evenly throughout the box and supports the soil.  More contact with the soil ???    

Thanks for finding the details for me yolos! I 'preciate it, a lot!!!!! 
Hey Boffer, if you're interested, would you make a bucket with a few actual wicks and see how that does with the 6" of MM?

Very interesting experiment. I would also think that an effective wicking box needs an effective wick. I have 4 wicking boxes (2- 2x12, 2- 2x6) and found that the various materials I used as wicks (mostly old shirts and blankets stuffed inside plastic coffee cans with holes) work well when the cistern box is at least 1/2 full but need to be kept very full during dry times or the plants show stress. At one point, my heavy feeders (corn and sunflowers) roots had completely taken over the wicking basket and became very hard to pry up at the end of the season. Last year, I installed an effective gavity fed watering grid from a large IBC tote for my 2x12 beds and this made a big difference. At least this way, any water that is not used right away is stored in the bottom cisterns and I can add more consistent moisture. Another reason I opted for the water grid was to help keep the roots more shallow growing.

On a big FYI for anyone considering a wicking bed, my worst problem has been the SLUGS!    When the cistern would overflow, I would have tons of slugs come pouring out of the overflow hole. I will be attempting to battle them w/ essential oils diluted and poured into the cisterns to get them under control this year. I did have a lot of success with Sluggo last year.

I'm concluding this experiment because I'm seeing no wicking action whatsoever, and I want chard for dinner.    

The magenta chard is getting thirsty.


When I disassembled the bucket, the MM and muslin were totally dry, and here you can see that the top one inch of gravel is dry too.

Water Usage Chart:

Experiment Conclusion: I've found one method that doesn't work.  
But I don't know for sure why it doesn't.

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camprn wrote:....Hey Boffer, if you're interested, would you  make a bucket with a few actual wicks and see how that does with the 6" of MM?

  Can do!

I dumped the bucket.  Stuck in 3 strips of terrycloth.


Filled it back up.  Added 2 chard seedlings.



I left the cloth ends exposed intentionally.  I'm thinking they'll dry out quickly in the heat and fan breeze, and that will encourage more wicking action.

Boffer, I like your new experiment.

Boffer, thank you for sharing.

Update using wicks in gravel:

Plants are looking healthy.



Although the reservoir is nearly empty, the plants' roots are finding sufficient water in the MM.

Water Usage Chart:

Using 'wicks' is working good so far.