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Soil mix

Manijahtor

Member
hello amigos! my english is no good but i wanted to hear opinions & critics about my mix.
im from argentina (south america) & been growing for 4 year, here we have great quality soil, the thing is that i noticed a few differences in the mix between countries, lets hear your opinions

30% worm castings
20% river undertow
20% compost
20% mix of peats (sphagnum & blonde)
10% vermiculite

+plus some oriental sand

then i add the fosforrus: 1spoonfull of fish flour and another spoonful of bat-guano in 8-9 litres of soil mix (for flowering i add another spoonfull of bone meal which it composts during flowering and starts giving "real" food after 1 month when guano is over)

i use the same mix in flowering but i add the potassium: 1spoonfull of wood ashess every 5 litres of soil mix

:thank you:
 

grapeman

Active member
Veteran
I think you would do well to add some "dolomite lime" to your mix since you are using peat in your mix.

I think you should visit this site
https://www.icmag.com/ic/showthread.php?t=53792
and follow one of the recipes on the first page. LC#1 or LC#2 for soil mixes. then below that you can read about different ways to fertilize your plants.
 
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Manijahtor

Member
thanks for the advice bro! but i really dont think its necesary to use dolomite, the worm casting neutralizes the peat, plus the ashes are very alcaline.
 

h.h.

Active member
Veteran
If it's working good for you...Cool.
I'm guessing about what the "undertow" is. River bottom?
Sounds like a lot of possible essentials along with a lot of fine material.
With only 10% vermiculite, I wonder about aeration and perched water.
Rather than change a mix that is working, adding a wick might be an idea. I would consider upping that 10% to 20 or 25% using rice hulls, pumice, diatomaceous earth, and char.
The wood ashes...I use eucalyptus, which has a high p content. They say on here to use corn cob or I think grapefruit or cucumber skins turned to ash. I soak mine and use the water. It still leaves some salts if not boiled down though. Not sure it makes any difference other than keeping the soil cleaner on the hands.
Again consider the dolomite. Cheap and doesn't contribute heavily to the alkalinity of your soil as I understand it. Being more of a buffer, it's more of an insurance policy.
Interesting to hear what you're using.
I hope the law's being good to you guys down there. I imagine the weather is. Good outside growing?
Look forward to the day when we can trade legally.
 

BurnOne

No damn given.
ICMag Donor
Veteran
thanks for the advice bro! but i really dont think its necesary to use dolomite, the worm casting neutralizes the peat, plus the ashes are very alcaline.

FAIL!
Dolomite also provides much needed calcium and magnesium.
If you know your recipe works, why come here and ask?

Burn1
 

h.h.

Active member
Veteran
The cal/mag might well be coming from the undertow. While we might form opinions of possible problems, he hasn't expressed any.
Even the earthworm castings should vary depending on local soil conditions and the eating habits producing the scrap. Compost for that matter. We don't know the mineral content of the water. The reason it's not sold at my local Lowe's is that people here don't use it unless they're growing pot in peat. With our local water and our local soil it becomes redundant.
Grapeman may have an opinion on alkaline water with high mineral content along with the use of dolomite. River water be nasty. LOL
 
S

SeaMaiden

The undertow, which I'm going to guess is comprised of the Andes, may or may not provide much in the way of Ca and Mg. I think that those particular elements, as most often found in rock, are rather easily eroded away by water, so the undertow could also be comprised primarily of silica, or volcanic or granitic or other igneous origin rocks. Dolomitic lime is comprised of compressed coral skeletons that have not been transformed except by time and pressure/weight (non-volcanic).

I should call a geologist friend to learn more.

I personally think that mix could use a larger proportion of compost, especially in relation to the peat and castings.
thanks for the advice bro! but i really dont think its necesary to use dolomite, the worm casting neutralizes the peat, plus the ashes are very alcaline.
That's not the only purpose of the dolomitic lime. It provides a huge amount of Ca and Mg as well as good trace elements. It's also much better for buffering than wood ashes are (and they don't provide much in the way of Ca or Mg).
 

Microbeman

The Logical Gardener
ICMag Donor
Veteran
You mean the killer undertow? That one?

Seamaiden; depends on the castings; My vermicompost is no different than compost except better; hehe
 

Manijahtor

Member
Dolomite
ok folks i will try some dolomite in my next mix!.

i forgot to tell you for micronutrients, such as magnesium, i use a spoonfull of diatomaceus earth every 8 litres.

River undertow/waste
i dont know if you call it river undertow i just kind of translate it from spanish "resaca de río" (i think the real word is "river waste"?) which is not taken from Andes but from Entre rios which is a province (state) in my country.
The river undertow is produced by the accumulation of vegetal residues under anaerobic conditions composting for a very long time. Like compost it has the same ammount of composted organic matter so it brings a lot of nutrients and also is very light it improves humidty conditions and the looseness, and a very large etccc (micorrizae for example).

Vermiculite
the airation i get it with the mix of peats and the river undertow
we used vermiculite a lot in our country on war times or economical situations to cheapen out the soil mix. like coco coir, perlite, vermiculite, or expanded clay pebbles it dont bring any nutriens and its a waste of a big porcentge in the mix.

I only have information in spanish, but ive found an article on mandala´s web which is very easy to read:

Soil.jpg

an example of quality potting soil - the texture is fluffy & soft, made from fine-grade sphagnum peat, the white specks are traces of perlite. Notice how little perlite professional potting soil contains (1% of total volume)! One of the most common mistakes growers make is to ruin their soil mix with high amounts of perlite.
coco coir and perlite only adds to the lack of available nutrients in a container.
It is best not to add any additional materials to your potting soil. Horticultural grade potting soil is perfectly mixed for the best air-water ratio. Adding more non-nutritive substances depletes the water retention capacity of the soil, it unnecessarily "stretches" the soil and reduces the total amount of nutrients available to the plant, and it creates dry pockets in the container.

Adding a large amount of perlite/vermiculite (some growers add as much as 25%!) is a completely outdated practice from 30-40 years ago when there was only a very small selection of horticultural potting soil available for non-commercial gardeners. It is one of the unfortunate harmful practices in cannabis cultivation that many still cling to although they do not understand the reason or consequences.

Especially harmful is to fill the bottom of the container with coarse materials such as expanded clay pebbles. This is where most roots grow down looking for water and nutrients! If they reach a dry and sterile layer of substrate the delicate root hairs shrivel, valuable space is lost where the plant requires rich soil that stores moisture and minerals.

If you are planting outdoor and your soil is too compact a modest addition of perlite/vermiculite or sand helps to increase drainage. Humus, such as from compost, is the best additive because it also provides many microorganisms and nutrients to the soil mix.

saludos hermanos!
 

h.h.

Active member
Veteran
"Undertow" is as good a description as any. I was thinking it might have been a bit muckier.
Sounds like your 10% figure is good.
You might consider replacing the vermiculite with some of he alternatives.
 

Manijahtor

Member
please hermano try to use simpler words form me and no slang please haha lol... i would apreciate it !
why are you saying i should replace the verm? what other alternatives??
i did a test: filled a container with perlite only and water it
then filled another container with vermiculite and also water it
i noticed that the humidity of the perlite evaporated within a couple of hours, while the verm container cointinued moist for a couple of days.
so thats why i think the vermiculite is good.
salúd!
 

mad librettist

Active member
Veteran
Hey bro, we are just a bit ahead of you here.

Vermiculite sucks!
perlite sucks!

I use diatomaceous earth baked into perlite size chunks, or clay treated the same way.
 

Bullfrog44

Active member
Veteran
Hey bro, we are just a bit ahead of you here.

Vermiculite sucks!
perlite sucks!

I use diatomaceous earth baked into perlite size chunks, or clay treated the same way.

I will second this. This year I used pumice and rick hulls, worked way better than Vermiculite/perlite.
 

h.h.

Active member
Veteran
Sorry about the slang. Take it as a compliment to your translation skills.
I thought the undertow might be finer materials with little aeration.

If your soil preforms well, 10% should be good. If not the 10% will be surrounded by finer material and not do it's job. To a certain point, using more allows for the use of more, finer, nutrient rich materials.
As Mad said, diatomaceous earth works well. Others use rice hulls. I think char helps as well.
Sounds like your undertow is doing the job of aeration. Is that due to compost content or due to sand? Agitated with water, I would use what is suspended in the water, examine what wasn't suspended and if it was real sandy, throw it out and replace it.
Or again, not. If it's not broken....
 

mad librettist

Active member
Veteran
I think the "undertow" we are referring to is the benthic layer.

Actually, I would not recommend benthos from a river as an aerobic compost replacement. You could add it to a pile though.

If I were using it, I would probably top dress or make a slurry and water with it. Simulated flooding, if you will.
 
S

SeaMaiden

I'm wondering if this is stuff harvested from regions that experience flooding and dry periods. Not at all what I was thinking initially (sandy stuff), but makes sense in the greater context of SA and what little I know of its aquatic systems. That undertow is likely some incredibly rich stuff, and if it's being pulled from typically ANaerobic areas, then I would wonder what the N levels are like, knowing what I do about denitrification in aquatic systems.

If you need extra moisture, then vermiculite is the way to go. If you need drainability and aeration, then that's where something like rice hulls (or peanut shells) works well as a replacement for perlite. Neither vermiculite or perlite provides any nutrient value, whereas the rice hulls do provide some nutrients as they are broken down.
 

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