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Can super soil be reused?

Emeraldo

Well-Known Member
...One example is the use of legumes as a cover crop. Farmers will plant legumes to restore SOM (soil organic matter) and improve the N (nitrogen) that are present and collected on the legumes roots. Most of the N is absorbed from the plants leaves from the air and stored in root nodules. When the legumes die back or are harvested, those roots give N back to the soil in the decomposition process.
...
Alfalfa is another such example of crops that actually produce N and restore SOM, and there are many. I have no reason to doubt that everything you said there is true. I guess the same might be true of cannabis root. You can leave the root in your soil and it will decompose and give back whatever it contains. It certainly does no harm.

I guess the only way to really know, as fact, if cannabis root is just bursting with nutrition is to have it tested. There isn't much I could find on the web to corroborate what, if any, nutritional value cannabis root in fact has.

Your analogy to legumes etc is nice -- yes, some plants' roots give N back -- but it doesn't establish as fact what was asserted by nunyabiz, namely, that cannabis root is just full of nutrients. I don't think it is honest to expect others to accept this kind of assertion without questioning the source. That's all I wanted to say.
 
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bobrown14

Grow Journal of the Month: Dec 2017
Thats a good point on testing. I can do that.

I have been just digging a small hole in the soil with old roots in it and re-using the soil over and over.

I have the original soil test from when I first mixed it up a few years ago.

I could take a sample with the roots in there and have it tested.

I'm pretty sure the soil is in better shape now than it was when it was first mixed up.

But yeah a great idea. I'm on it.

Soil test will go in the mail tomorrow. I'll report back.
 

Emeraldo

Well-Known Member
Thats a good point on testing. I can do that.

I have been just digging a small hole in the soil with old roots in it and re-using the soil over and over.

I have the original soil test from when I first mixed it up a few years ago.

I could take a sample with the roots in there and have it tested.

I'm pretty sure the soil is in better shape now than it was when it was first mixed up.

But yeah a great idea. I'm on it.

Soil test will go in the mail tomorrow. I'll report back.
Bob, it might make a difference if you flushed before harvest, washing out any nutrients that might be there. So individual flushing practices, as well as what amendments were added to the soil during a grow, would tend to affect dead root content and make it difficult to generalize from one grower to the next.

Bravo for having the test done. As for what you test, why not extract the roots from the soil as much as possible, so all you send in for testing is a wad of roots? That would provide the tester with a more concentrated sample of what ought to be in there.

If you just send soil with roots in it, a soil test will give a result reflecting the soil as a whole, not just the roots. If you want to know whether dead roots are full of nutrients, isolating the roots from the soil might be a more accurate way to go, imho.

This ought to be interesting...
 
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bobrown14

Grow Journal of the Month: Dec 2017
Im not sure about this flushing concept you speak of??

Soil test is what it is. I doubt they will test roots. I'm not even sure what the point wood be??
I kinda want to see how my soil ether depleted or got better more in a general sense.



My original soil mix has 1/3 peat moss in it as the base mix. Peat moss is mainly all roots from a peat bog. Since the peat bogs are alive when exposed to air and water it wood make sense that there's a fair amount of nutrients there.
 

Emeraldo

Well-Known Member
Im not sure about this flushing concept you speak of??
If you've been growing cannabis for a few years, you would in all likelihood have heard of flushing. The soil is flushed generously with water to clean out the soil. Flushing is used in several contexts: soil toxicity owing to an excess of some kind, say for example excess N. You flush also in flowering to remove old nutrients used in the vegetative phase before flowering food is given during the last weeks of flowering. Flushing is also performed about one week before harvest to wash out the cannabis plant and improve taste. Flushing is a practice followed by many professional and hobby cannabis growers. I flush before harvest, and also once had to flush out soil that had a N excess causing leaf clawing.

Flushing removes nutrients from the roots. So dead roots that have been flushed will certainly have less nutrients that they would if no flushing had been done. That is why I was surprized at nunyabuzz' statement (about roots being full of nutrients) and took the position that I doubted that the cannabis root you find in your soil after harvest would have little, if any, nutrient value. I just assumed most people flush.

Soil test is what it is. I doubt they will test roots. I'm not even sure what the point wood be??
I kinda want to see how my soil ether depleted or got better more in a general sense.

My original soil mix has 1/3 peat moss in it as the base mix. Peat moss is mainly all roots from a peat bog. Since the peat bogs are alive when exposed to air and water it wood make sense that there's a fair amount of nutrients there.
Sorry, I thought testing cannabis roots was what prompted your intention to test, you know, the debate with nunyabix. Of course cannabis root can be tested. Why couldnt it be tested?

So anyway I did some checking on the nutritional value of peat moss. It does not contain nutrients. Univ. of Vermont published on that topic. Peat moss or compost? Here's what the U of VT said about peat moss (without the comparison to compost):

"Peat moss has few if any nutrients... Peat moss helps the soil hold nutrients by increasing what is called the CEC or cation exchange capacity.... Peat moss has a low pH, so if you use much, lime should be added as well... Peat moss doesn't compact, so can last for years in soils, providing good aeration and water holding."

Another article said this: "Despite being organic, peat moss is not really fertile. It doesn’t contain nutrients plants need to grow. It has some beneficial microorganisms, but that’s all. On the other hand, the nutrient content is not absolute zero, either. Peat moss does contain a bit of nutrients, minerals and beneficial microorganisms. In this sense, peat moss will not ruin the fertility of your soil. However, you will probably need to use more than just peat moss to make your plants grow strong and healthy." Peat Moss: Benefits and Disadvantages - Sunday Gardener

So Bob, your test of peat moss will probably not reveal nutrients. Peat moss may have some nutrient value, but the in the main peat moss is not known or chosen for that. It lowers pH and gives the aeration. But you will get a good read on your own soil as a whole, so go for it.

Not the same as testing the cannabis root itself, which is what the hot debate here was about.

Cheers
 
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bobrown14

Grow Journal of the Month: Dec 2017
I know about peat moss. Also have a peat bog on my property in Canada. It's alive 420%.

The peat moss we buy in a bag, yes its been processed and could be used in a soil-less medium with chemical fertilizers to grow plants in. It will break down and compost tho, may not contain a lot of nutrients it will contain some. You do know that our oil/gas supply we get from wells are old peat bogs that have been under pressure and time for millions of years. We hoo-mans take that oil and turn it into lots of things one of them is fertilizer.

On flushing, I've been growing organically for a very long time. I've never flushed anything other than my lou.

Show me some science that shows that pouring on extra water into soil will wash out nutrients.

It doesn't happen and its not possible chemically or physically.

1 reason, and you pointed to it in your last post is Cation Exchange Capacity.

How can we have a soil with CEC and also a soil with "extra" nutrients that are sitting there waiting to somehow attach to water molecules and wash out of soil.

You MIGHT be able to wash out a very small proportion of EXTRA nitrogen that is in a soluble form from the addition of Ammonium Nitrate and it's N relatives. In an organic soil its not going to happen.

I have a soil mix that incorporates 1/3 peat moss, 1/3 compost/vermi-compost and 1/3 aeration. I add amendments to that bass mix.

I've been using it for several years over and over again. Its got plenty of nutrients in it. This used soil that contains 1/3 peat moss is the soil I sent out to have tested. I have the original test when it was first mixed. We can make a direct comparison. I'm going to bet its got better nutrient profile now than it did a few years ago.

Here's a quote from another university study about using peat along with compost:

"A solution to these differences between peat moss and compost is to use both, getting the benefits of each. Some incorporate peat moss and compost when planting, then topdress perennial plants with compost in subsequent years. Peat moss reduces the tendency of some compost to compact, and may extend the life of compost several fold."

That highlighted part there ^^^^ I find interesting. How does peat moss extend the life of compost?

You mentioned me testing peat moss?? Not sure why. I'm having my soil mix tested that contains 1/3 peat moss. It's already been tested and I know that the soil mix is a good one.
 

Emeraldo

Well-Known Member
...Show me some science that shows that pouring on extra water into soil will wash out nutrients.

It doesn't happen and its not possible chemically or physically.
Well, Bob, for someone who only a day ago was not sure what flushing is, you certainly seem to have well-formed and fixed opinions about it. There is so much information about how flushing washes out excess nutrients out of soil that I don't think I need to go into detail, but here are some helpful links to get you going.






That will have to do for now. Flushing is a widely used remedy for toxicity due to "too much". I had a plant's leaves doing the crawl, and flushing fixed it. I also flush a week or so before harvest. Since you have only flushed the lou, maybe this is something you might find useful.

On our new topic (whether peat moss is, by itself, a source of nutrients) I have no doubt that you "know about" peat moss. I believe that you've got good soil (1/3 peat moss) and that you might even live on a bog. :Rasta: You point to a good technique of using compost and peat moss together, and you've cited an article that describes the benefits of doing that. That's all great and believable. It doesn't go to the issue of our new topic. And I don't agree that you know everything about peat moss.

We'll just have to agree to amicably disagree on the issue of the nutrient value of peat moss. For my part, I've never thought that peat contains nutrients of any significant amount, and the materials I cited to you above confirm my position completely. If your peat moss seems to have nutrients in it, maybe those nutrients got into your peat moss from the environment it is growing in.

So why do we use it in a soil mix? Because it improves the soil by lowering pH and by improving aeration and waterflow. I'd guess that's also probably how peat moss extends the life of compost, by creating a healthy root environment in several aspects at once. 'Nuff said.

Emeraldo
 
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Vegan4life

Well-Known Member
I thought flushing was for Hydro growers and toilets?... Not for LOS growers?... LOS growers feed the soil not the plants, if LOS grower has to use bottled nutes, the soil is not right, (just my understanding, I am a Rookie)...
 
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Emeraldo

Well-Known Member
I thought flushing was for Hydro growers and toilets?... Not for LOS growers?... LOS growers feed the soil not the plants, if LOS grower has to use bottled nutes, the soil is not right, (just my understanding, I am a Rookie)...
Maybe there is a toilet big enough for one or more LOS growers to climb in, pull the lever, and... um... FLUSH!:D Ha-ha
 

bobrown14

Grow Journal of the Month: Dec 2017
I thought flushing was for Hydro growers and toilets?... Not for LOS growers?... LOS growers feed the soil not the plants, if LOS grower has to use bottled nutes, the soil is not right, (just my understanding, I am a Rookie)...

Vegan4life, you are spot on.

Emeraldo, by "show me the science" I'm talking about an article written by an actual scientist that studies soil science or something of that sort.

I could write: "flushing is for toilets" V4L - doesn't make it science although there's plenty of anecdotal evidence this is a correct statement.

Ok lets talk science.

Here's a good article written but actual soil scientists about soil nutrient "leaching". If you read it, its actually geared toward this as being a PROBLEM not a solution.

http://www.css.cornell.edu/faculty/lehmann/publ/Lehmann et al., 2003, Leaching CABI book.pdf

You will also read that depending on type of soil and the CEC of that soil, only certain nutrients are leached out based on their conductive charge. Anions and Cations are a thing. They attract and combine with nutrients in the soil. That combination is what keeps them from being able to wash away with water which has neither a negative nor positive charge.

Water aka H2o has neither a positive nor a negative charge. Nutrients in soil all have a charge associated with them. So they will not be attracted to water.

Your question should not be; "When should I flush" but;

"How to I get the plants roots to uptake water along with the nutrients already in the soil?"

Plants will not uptake more nutrients than they need and somehow store them in some mythical cells that will then release them when you add extra water to the soil. This is just non-sense really.

Water is absorbed by the roots by osmosis. It's a pretty cool thing. Then there's the vascular system and how does water go up a column against gravity? These are the real questions.

The flush is for hydro growers. Likely they only do that when they have issues with the roots like root rot or something else like pH issue in the water/nutrient they are cycling thru the system (which has no soil in it).

I know that a lot of "experts" flush or talk about flushing. Doesn't make it science or even true.

I have a lot more science on this topic. It's been hashed around some.

The cool thing is there's a bunch of universities with soil labs. This topic has been studied and reported on.
 

conradino23

Grow Journal of the Year: 2017 - Grow Journal of the Month: Sept 2017
Yeah one thing I found baffling is how much bro science circulates around weed forums and how difficult it is for growers to actually tell what credible science is.

For the record if something is published in High Times or online it doesn’t become the truth automatically. It can’t be treated as truth if it comes from one off experiment in your tent either, especially if results are not measured against control group. That’s what’s called anecdotal evidence, which falls under personal bias.

Right conclusions can be only produced if all conditions of scientific experiment are met and sample is big enough to have statistic validity. Otherwise it’s just bro science!
 

Emeraldo

Well-Known Member
...Your question should not be; "When should I flush" but;

"How to I get the plants roots to uptake water along with the nutrients already in the soil?"

Plants will not uptake more nutrients than they need and somehow store them in some mythical cells that will then release them when you add extra water to the soil. This is just non-sense really.
Bob, apart from the puns about "flushing", hee hee :p, I would say in response to yours, that I did not ask a question about when to flush, or, for that matter, about how flushing could remove nutrients from roots. I never asked either of those questions. Just to be clear.

Flushing during veg and during flowering as well as right before harvest, as it is treated in many discussion forums, is simply about washing excess nutrients (be they organic or "bottled" nutrients) out of the soil. Flushing helps remove a toxicity due to too much nitrogen, for example, and also help prepare your plant to receive flowering nutrients and to help with drying and curing by washing out material that would otherwise leave a taste in the cured bud. In that connection, nutrients are removed from the soil and from root material -- not from the plant above ground -- that would otherwise (without flushing) stay in the plant. But since roots are permeable via osmosis, flushing the roots has its benefits. Usually, plants are flushed about 2 weeks before harvest, so that the plant can then use up what nutrients are left, the leaves turn yellow due to lack of nutrients, and the bud will taste smooth.

Here's a link to a blog on flushing roots: Flushing roots at the end of flowering | Blog Philosopher Seeds The blog explains: "Depending on the variety of cannabis being grown, the plant’s nutrient demand usually reaches its peak after about 40-60 days of flowering. From this point onwards, the plant begins to reduce the consumption of nutrients, in particular phosphorus and potassium (the two main nutrients used during this stage).
Therefore, if the plant has been overfed or if fertiliser residues remain in the substrate, it will continue to feed on them, something we want to avoid, as it’s best to harvest cannabis flowers when the plant has exhausted all the available nutrients in the substrate and in its own reserves. To achieve this we must use water only when we irrigate the plants during the last 15-20 days prior to harvest (as well as any products specifically designed to aid flushing)."

You might check out Green House Seeds' videos on their strains, e.g., Arjan's Haze #1, where Arjan Roskam recommends flushing at several different junctures to improve plant performance. Arjan is of course highly professional and, well, I guess, experienced, too... :Rasta:

I posted links to many websites discussing flushing in a prior post to you. Based on that validated information, I am surprized that you think flushing is expected to actually remove nutrients that the plant has taken up already. Where did you get that twist? For someone who just this week didn't even know what "the concept of flushing" was about, it seems odd to me that your next step has been to mischaracterize flushing as something it's not. And you did this after I posted for you several links that should've helped you. Well, I'm done with that. Anyway, what you said above is not the purpose of flushing as described by those who practice it. The only thing true about your post above is the last sentence: What you said is non-sense.

But hey if you can find a big enough toilet, why not climb in and try your hand at flushing? :cool:
 
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Emeraldo

Well-Known Member
Yeah one thing I found baffling is how much bro science circulates around weed forums and how difficult it is for growers to actually tell what credible science is.

For the record if something is published in High Times or online it doesn’t become the truth automatically. It can’t be treated as truth if it comes from one off experiment in your tent either, especially if results are not measured against control group. That’s what’s called anecdotal evidence, which falls under personal bias.

Right conclusions can be only produced if all conditions of scientific experiment are met and sample is big enough to have statistic validity. Otherwise it’s just bro science!
conradino23, this is a huge point you have made, but I'm learning that the conflict between fact (science) and opinion (bias) is built into this kind of informal forum. It's nice to communicate with other growers about general issues, but if one expects to receive validated information, the chances are better you'll get misinformation. Sometimes it even seems there are trolls who put out disinformation.
 

conradino23

Grow Journal of the Year: 2017 - Grow Journal of the Month: Sept 2017
And that’s how bullshit keeps on living. Once you get inaccurate or outright wrong information and you embrace, then the chance is that it becomes locked in your mindset and shields you from the facts, which I see happening all the time!

Sure at the end of the day most growers just want to grow their weed and do it painlessly and rarely get to the bottom of things, which I don’t think is right, but that’s how it is.

The fact is that we know very few facts about growing cannabis and until a complete set of facts is built we’re floating between magic and half-truths at best.

It’s gonna take another decade to confirm what we know, abolish the myths and discover what we don’t know.
 

Emeraldo

Well-Known Member
And that’s how bullshit keeps on living. Once you get inaccurate or outright wrong information and you embrace, then the chance is that it becomes locked in your mindset and shields you from the facts, which I see happening all the time! ...
There are many sincere, experienced folks who share good, validated information and who will help solve a problem when you run into one you can't solve. But unfortunately you have to learn to tell the bullshitters from the sincere. You can usually tell a bullshitter when you ask them to substantiate what they are saying and they feel their ego has been challenged -- you caught 'em with their pants down -- and then they get nasty or vindictive. I don't know what, from the bullshitter's perspective, is gained by putting out false or misleading information, but apparently they get off on pretending to be knowledgeable. False information, if left uncorrected, can be catastrophic for an innocent newbie! :eek:
 
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conradino23

Grow Journal of the Year: 2017 - Grow Journal of the Month: Sept 2017
2nd that, that’s exactly what I see... and I know why, people just like to be treated as gurus and get rep from noobs. It’s really the basis of this industry and now there’s money involved, which makes it even worse!
 

SmokingWings

Well-Known Member
Back to the original question.

Yes, most soils can be reused as far as I know. A certain amount of nutrients and organic material would be lost when harvesting flowers and throwing away leaves, stems and root but overall a good soil will have plenty left to last 2, 3 or more growing cycles before any amending has to be done again. I figure that my big expense and work load was building up the soil the first time. After that it is just a $1 or $2 every couple of months adding something like a cup of dried fish parts or shredded feathers or something similar.

As for the roots, they are organic material and I would think that they contain pretty much the same nutrients pound for pound as do the stems or the leaves. Bonus, the way I see it, is that the dead roots left in my soil also contain the various hormones that the plant used to grow and maintain those roots. So, why not leave them in.

If it is an artificial soil such as those that are used with water culturing or hydroponic style growing then I don't know. I find that style of growing fascinating and part of the future but I like a natural or organic soil more.

In the photo is a 17 gallon bucket with about 5-7 gallons of soil from before and a 5 gallon block of roots and soil that were in a Kitty Litter bucket. I added a couple tablespoons of Neem Seed, couple tablespoons of bloodmeal and about a 1/4 cup each of Down To Earth's Bio-Fish and their Bio-Live. Then I just start mixing with the hand trowel and the roots get cut and broken into small pieces and become part of the mix just as if I had added a handful of peat moss. (The soil mix was moist when I took the photos so I figure it is the ceiling lights in the basement growing room that make it look dry.)
soil-roots.jpg


soil-roots2.jpg
 

Emeraldo

Well-Known Member
Back to the original question.

Yes, most soils can be reused as far as I know. A certain amount of nutrients and organic material would be lost when harvesting flowers and throwing away leaves, stems and root but overall a good soil will have plenty left to last 2, 3 or more growing cycles before any amending has to be done again. I figure that my big expense and work load was building up the soil the first time. After that it is just a $1 or $2 every couple of months adding something like a cup of dried fish parts or shredded feathers or something similar.

As for the roots, they are organic material and I would think that they contain pretty much the same nutrients pound for pound as do the stems or the leaves. Bonus, the way I see it, is that the dead roots left in my soil also contain the various hormones that the plant used to grow and maintain those roots. So, why not leave them in.

If it is an artificial soil such as those that are used with water culturing or hydroponic style growing then I don't know. I find that style of growing fascinating and part of the future but I like a natural or organic soil more.

In the photo is a 17 gallon bucket with about 5-7 gallons of soil from before and a 5 gallon block of roots and soil that were in a Kitty Litter bucket. I added a couple tablespoons of Neem Seed, couple tablespoons of bloodmeal and about a 1/4 cup each of Down To Earth's Bio-Fish and their Bio-Live. Then I just start mixing with the hand trowel and the roots get cut and broken into small pieces and become part of the mix just as if I had added a handful of peat moss. (The soil mix was moist when I took the photos so I figure it is the ceiling lights in the basement growing room that make it look dry.)
soil-roots.jpg


soil-roots2.jpg
Very common-sensical. Back to the OP.

Btw, looks like a very good soil mix, imho.

So..... Can super soil be re-used? Yes

Are the dead cannabis roots full of -- or void of -- nutrients? (To which you've added: hormones) We don't know. No evidence, either way. But it's been a fun debate. :Rasta:

That's really interesting what you say. Did you really grow cannabis in a 5 gal block of root material? Sure, it's prolly as good a substrate fiber as any, or better than any as far as I know, at least for the root growth of the plant to be grown.

What does it add by way of nutrition, do you think? For a supersoil? Nah, supersoil has to have an abundance of everything. Do you think dead root provides the real deal when it comes to everything? No offense, just askin.

Maybe there are other topics under the heading of re-using super soil... Hmmm
 
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conradino23

Grow Journal of the Year: 2017 - Grow Journal of the Month: Sept 2017
Actually we know that roots are built differently than stems and leaves :) Roots accumulate phosphorus in large concentration together with trace minerals while leaves and stems are mostly built of nitrogen, so by removing either one of these you change what comes back to soil. I do no-till in air-pots, so I let roots decompose and I don’t see any problems for 6-7 runs. Then limits start to show up which means yield starts going down although you hit the mark with quality... very tasty buds :smokin2:
 

Emeraldo

Well-Known Member
Actually we know that roots are built differently than stems and leaves :) Roots accumulate phosphorus in large concentration together with trace minerals while leaves and stems are mostly built of nitrogen, so by removing either one of these you change what comes back to soil. I do no-till in air-pots, so I let roots decompose and I don’t see any problems for 6-7 runs. Then limits start to show up which means yield starts going down although you hit the mark with quality... very tasty buds :smokin2:
Do you amend the soil between runs? So after 6 or 7 runs, what's the problem? The soil is exhausted? What do you do, mix up new soil or amend the old and run again?
 
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