You Gotta SIP, Not Slurp

[thailer]

y. Overall, shallow wicking treatments were the more favourable treatments in terms of
WUE and yield. This may be related to the relatively shallow (medium) rooting depth of tomatoes.

the tomato roots didn't grow past a foot in the field soil? well cannabis plants reach farther than that and it says that the 600mm (23") field soil was course and that would have affected its ability to wick water which is one of the points about wicking. Earthbox says with their SIPs that you can't even use compost because of the different aggregate size to peat moss. so i switched to a 2:1:1 base soil recipe and it works great. regular 1:1:1 base soil works pretty good but on hot summer days with a big plant, it seems to need watered more.

The deep soil bed wicking treatment (T1 W300/P600) had a lower yield than its corresponding
surface treatment, and was also lower than the shallower wicking treatments. The reason for the low
yield and WUE in T1 W300/P600 was initially considered to be insufficient supply of water to the root
zone, due to the greater height and the resultant difficulty in maintaining water supply to the roots
by capillary rise (noting that the amount of capillary water present in soil decreased with distance
above the water table). In support of this theory, soil evaporation observed in the unplanted deep
wicking treatment (T3 WN300/P600) was low when compared with the 300 mm WB T8 WN300/P300
treatment (Table 1), suggesting that less water was able to reach the surface by capillary rise. However,
the ETc in the deep soil WBs was not significantly different from the ETc in the shallower wicking
treatments, suggesting that a similar amount of water must have been delivered to the plant, despite
the greater soil depth. Although there was about a 22% water reduction in T1 W300/P600 relative to
the surface treatment (T2 S0/P600) which had an equivalent soil depth (Table 2), the wicking treatment
delivered lower yields and thus failed to produce a significant improvement in WUE. It should be
noted that the percentage of unmarketable fruits was lower in WBs compared to surface treatments
for the shallow soil plots, but not for the deep soil treatments. On this basis, it is inferred that the
use of wicking irrigation to grow tomatoes with a 600 mm soil depth was not effective. This depth
of wicking bed may, however, be suitable for deeper rooted plants.

they basically say that the deeper bed had too much air on top and that the shallow roots of tom's didn't grow down to the wetter soil area.

 

[thailer]

here's one study with soybeans:

Effect of Water Table Depth on Soybean Water Use, Growth, and Yield Parameters
by Yavuz F. Fidantemiz 1,Xinhua Jia 1,Aaron L.M. Daigh 2,Harlene Hatterman-Valenti 3,Dean D. Steele 1,Ali R. Niaghi 1OrcID andHalis Simsek 1,*OrcID
1
Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND 58108-6050, USA
2
Department of Soil Science, North Dakota State University, Fargo, ND 58108-6050, USA
3
Department of Plant Science, North Dakota State University, Fargo, ND 58108-6050, USA
*
Author to whom correspondence should be addressed.
Water 2019, 11(5), 931; https://doi.org/10.3390/w11050931
Received: 2 April 2019 / Revised: 22 April 2019 / Accepted: 26 April 2019 / Published: 2 May 2019
(This article belongs to the Special Issue Innovative Water Management and Reuse)
Download PDF Browse Figures Citation Export
Abstract
Water table contribution to plant water use is a significant element in improving water use efficiency (WUE) for agricultural water management. In this study, lysimeter experiments were conducted in a controlled greenhouse environment to investigate the response of soybean water uptake and growth parameters under four different water table depths (WTD) (30, 50, 70, and 90 cm). Soybean crop water use, WUE, and root distribution under the different WTD were examined. For 30, 50, 70, and 90 cm of WTD treatments, the average water table contributions were 89, 83, 79, and 72%; the grain yields were 15.1, 10.5, 14.1, and 17.2 g/lys.; and the WUEs were 0.22, 0.18, 0.25, and 0.31 g/lys./cm, respectively. Further analysis of the root mass and proportional distribution among the different soil layers illustrated that the lysimeters with 70 and 90 cm WTD had greater root mass with higher root distribution at 40–75 cm of the soil layer. The results indicated that 70 and 90 cm of constant WTD can yield higher grain yield and biomasses with greater WUE and better root distribution than the irrigated or shallow WTD treatments.

https://www.mdpi.com/2073-4441/11/5/931/htm

this one uses field soil as well but uses loamy soil which would work much better than the course soils of australia which is what the other study uses. think it had clay or something else.

 

[flylowgethigh]

If the soil is directly on top of the wick (say perlite), with no barrier like fabric, do the roots stop at the soil/perlite interface, or will they grow down into the perlite wick also?

 

[Bmac1]

If the proper air gap exists they should air prune themselves.

 

[thailer]

they won't air wick. the cannabis plant sends down these thicker anchor type roots that shoot down into the reservoir and into the drainage pipes soaking up water while thinner feeder roots go right down to the perlite soil interface and they latch on to the perlite air section and cling to it. one i ripped the drainage pipes off, and then scraped away perlite that wasn't attached, there was still a two inch thick layer of perlite root mat. then a thick mat of roots on the bottom of the soil which grew upwards.


you can see the attached pic below what the tote looked like after the inside contents were dumped out. theres roots still stuck to the bottom which shows air and roots go down to the water bottom and don't rot all not getting air pumped inside or other stuff. its simple. easy. smoooth. lol

 

[Bmac1]

I stand corrected

 

[thailer]

i hope you all are having a great day! i have my four sips built but only three fit inside the room. i bought some foam flooring puzzle like squares that connect and are rainbow kid colored. i put those down before i put the sips down because the smaller totes i would raise off the cement using harbor freight furniture dollies. when you raise up the sips on something, even this 1/2" thick flooring, i also have to use it with the control box so i have the control box on a small section using the puzzle edges that detach so it is the same height using scrap pieces.

anyways, i went out there later and found the bulkhead on one wasn't screwed in all the way and was leaking, so that got an extra tightening. i am just waiting for some clones to take off and i need to switch the lights around. also need to go to the store to buy fertilizer but i guess they have basically shut down for covid and i am wondering where i am gonna buy it now. probably gotta drive to Concentrates in portland.

 

[eyesdownchronic]

the tomato roots didn't grow past a foot in the field soil? well cannabis plants reach farther than that and it says that the 600mm (23") field soil was course and that would have affected its ability to wick water which is one of the points about wicking. Earthbox says with their SIPs that you can't even use compost because of the different aggregate size to peat moss. so i switched to a 2:1:1 base soil recipe and it works great. regular 1:1:1 base soil works pretty good but on hot summer days with a big plant, it seems to need watered more.

Huh, does this mean that when running sips your soil has to be a monoculture.? I was planning on using coco and hydroton, with a little compost. will the hydroton+ compost disrupt the ability of the soil to wick? i haven heard of that before.

or are they reffering to very high levels of compost in the mix. iirc the cootz mix call for like 1/3 compost.

 

[thailer]

Huh, does this mean that when running sips your soil has to be a monoculture.? I was planning on using coco and hydroton, with a little compost. will the hydroton+ compost disrupt the ability of the soil to wick? i haven heard of that before.

or are they reffering to very high levels of compost in the mix. iirc the cootz mix call for like 1/3 compost.

that was just on the earthbox info for their product. they say to use slow release nutes and peat moss but i am using 25% compost and the 1/3 works fine too. i really don't know why they even say that except on principle, wicking works best when you use a medium that can make surface contact with the medium underneath and on top of it. maybe over the past two years they have removed that from their info? thats what i read in the beginning of this little venture. i ignored it and it works. i think it is regarding field soil which seems to be the only thing that is studied in these articles. lol

 

[Bmac1]

I use a water only mix with lots of compost/ewc in mine without issue. My mix is kind of a Coots/Stank Bros hybrid.

 

[thailer]

However, the seed weight and total biomass of the treatments with constant water table depths were higher than the irrigated treatment. The deepest water table depth illustrated the highest biomass and seed weight compared to the other treatments. The roots response to the different water table depths were strongly indicated a relationship between root development and water table depth. The linear relationship was observed between the water table depth and the root distribution and mass.

they also screened the soil before they added it to the sips so it was uniform and then added sand till it was considered ideal. so this is much different than using australian soil i am quoting below,

The experimental soil was
purchased from a local supplier, and was a type especially developed for gardening, so was taken
as representative of urban garden soils. The soil was a poorly graded sandy soil, according to the
unified soil classification system (USCS) (90% sand and <5% fines). It had a field capacity of 30%,
porosity of 49%, dry bulk density of 1.33 g/cm3
, organic matter of 4.5%, and pH of 7.7.

 

[flylowgethigh]

The jury is still out on watering a bag by setting it onto a moist perlite SIP bed. The roots will be confined to the bag, and won't be able to reach into the perlite. Hopefully the kind of fabric they use in bags will encourage wicking - I am drying my test bag now.

Those roots in the drain tubes?, and nasty perlite entangled with roots, look like a mess to clean up. I really want this living soil / bag thing to work. Dump the used soil into the reclaim bin, and start again with a fresh batch from the big bin. Perlite lined totes stay in the tent, but also come out easily, with or without the planted bag in the tote. Easy logistics.

 

[thailer]

there is info at another forum on Noobwannab's Self Wicking Smartpot Ghetto Setup that has a long thread with loads of people praising the technique of SWICK which is fabric pot's on top of perlite beds in individual pots. i've used a 3 gallon fabric bag set inside a 5 gallon bucket with perlite in the bucket and the bag does wick and the roots will go into the perlite and YES it is a huge bitch to clean up.

inside these sip totes i made, the soil sits on a compacted bed of perlite so when i am removing soil with my hands, i can feel the perlite bottom and i just leave some of the soil and scrape what i want off and replace with freshened up soil as needed. i don't have the perlite all over the floor and stuck to the fabric bags when i harvest if i choose to pull them out.

i bet if you leave the fabric bag in place permanently, and scoop soil out of the bag instead of removing the bag itself to add new or refresh soil, you won't have a mess of perlite with your setup. just don't lift the bag out from the perlite bed and find away around it to complete your task.

 

[SamsonsRiddle]

IF YOU USE THE NOOBWANNEB'S VERSION OF FABRIC POTS ON TOP OF RESERVOIR/PERLITE; TO AVOID ROOTS GROWING INTO PERLITE, JUST PICK THEM UP EVERYONE ONCE IN A WHILE. I LIKE TO SPIN THEM. CAN'T HELP IF USING SCROG. IF YOU HAVE A NORMAL MIX YOU LIKE TO USE, YOU MAY WANT TO ADD A LITTLE EXTRA PERLITE....



DON'T USE ANYTHING UNDER 3 GALLON FABRIC POTS, 2 GALLON AND BELOW WILL WICK UP TOO MUCH WATER.

 

[flylowgethigh]

there is info at another forum on Noobwannab's Self Wicking Smartpot Ghetto Setup that has a long thread with loads of people praising the technique of SWICK which is fabric pot's on top of perlite beds in individual pots. i've used a 3 gallon fabric bag set inside a 5 gallon bucket with perlite in the bucket and the bag does wick and the roots will go into the perlite and YES it is a huge bitch to clean up.

inside these sip totes i made, the soil sits on a compacted bed of perlite so when i am removing soil with my hands, i can feel the perlite bottom and i just leave some of the soil and scrape what i want off and replace with freshened up soil as needed. i don't have the perlite all over the floor and stuck to the fabric bags when i harvest if i choose to pull them out.

i bet if you leave the fabric bag in place permanently, and scoop soil out of the bag instead of removing the bag itself to add new or refresh soil, you won't have a mess of perlite with your setup. just don't lift the bag out from the perlite bed and find away around it to complete your task.

Thanks for the insights. I can deal with the tote/bag/soil/rootball outside, I suppose. Maybe on the garden spot. How the hell do the roots get through the bag? So lifting the bag off the perlite bed acts as an air barrier and kills those adventurous roots? My lower scrogs are part of the tote, but I don't have to use them. It's starting to sound like the bag isn't adding much either.

That Blumat moisture sensor is pretty good, not sure about the cheap remote one. I think the blumat could be used to measure moisture as you add water to the soil via the SIP. AND watch the plant suck down the moisture. Run the SIP until the blumat showed whatever moisture you like, then let the soil dry again. On my little test, the pot was taking days to drop moisture, even just a little. Having a thirsty plant will be totally different.

I am glad to hear that a bag on top of the perlite will wick and work. I am going to try my 7 gallon stuff for this first run, but already I am thinking of bigger stuff for the flower tent on a later run. I have the soil, so might as well use it. Bigger totes, and I could use the same kind of drain-pipe deal inside them that you guys are.

So, with the 1/2 inch black HDPE tubing, there is light in the tunnel. 1/8 turn quick disconnects, means you only put the 1/2" tube stuff together once:



Now that I have the 1/2" bulkhead stuff, I would not use the screw-in stuff I have on the tote. The bulkhead 90 can be easily positioned, and stays pretty tight from a slight taper. The barbs are bigger on them, so putting the tubing in boiling water was necessary to get it on the barbed end. Notice the increased diameter compared to the other barbed end.

 

[thailer]

if you place fabric bags close enough so they touch, the roots will grow into the neighboring bag too. they will grow anywhere moist so they escape the moist bag of soil and grow straight into the moist perlite.

i think when you lift the pots from the perlite every couple days, it pulls the roots out of the perlite and exposes them to air where they air wick themselves. i think that if you just left them there permanently, you won't have to lift them out of the perlite. at the end i would just leave the fabric pot in place so you don't have to deal with the roots making a mess with the perlite.

on that study earlier they used a SIP that had no plant at all and it held moisture a lot longer than ones with plants.

 

[flylowgethigh]

Mr. Thailer, I think you have pointed out the big flaw in this design. Roots will go down through the perlite, through the bag fabric barrier, and into the grill, and into the drain. UNLESS the grill and drain is dried and aired.

But really, why does my system need perlite anyways? Why can't I just wet the bottom of my tote/bag SIP style (bottom so much of the bag), and then drop the water below the grill the bag sits on during dry time? Hybrid of what I had and a SIP. Keep the roots in the bag like an earthbox.

Why do I keep thinkin of a tote in a tote, and a grill, and floating wick media, and some kind of simple way? Something that would float up and wet the bag, then during drying would sink away and expose the bottom of the bag to air?

Deep stoner thoughts at work again.

 

[thailer]

But really, why does my system need perlite anyways? Why can't I just wet the bottom of my tote/bag SIP style (bottom so much of the bag), and then drop the water below the grill the bag sits on during dry time? Hybrid of what I had and a SIP. Keep the roots in the bag like an earthbox.

as long as you're not flooding the soil itself and just flooding the perlite, i don't have too many reasons why it wouldn't work. i mean i am just guessing since i haven't used anything like that but part of the way capillary action works is that the water has some pooled at the bottom in which it uses as a base to thrust upwards vertically. if you flood it manually yourself and get the perlite bed wet and then drain it, i think this would have to happen as often as a hydroponic ebb and flow system to keep the perlite wet. you would have to keep up with the different surges in drinking that plants have like during stretch and you have more manual control but part of the beauty i like about the SIP is the set it and forget it so the water is added to the soil as the plant drinks it up so i am not guessing during high drinking periods and i am not overwatering when the plant slows down in uptake of water. so thats just my guesses on how it will work. i suggest you give it a go and see how you like it.

edit: i am not sure if just flooding it periodically will allow it to wick up enough to the soil and keep it moist

 

[eyesdownchronic]

Wondering what you guys think about using a standard mulch vs. living mulch. not sure which one i want to implement. leaning towards the living mulch but I' not sure...

TIA

 

[thailer]

flylowgethigh, in reply to a comment on a picture elsewhere, yes that is a 20 gallon fabric pot on a bed of perlite but i wasn't using it as a SWICK at the time. it would need more perlite or pumice in the mortar pan but that is basically my old SWICK setup; sans a few inches worth of aeration.