Experienced Organic Grower to Answer Your Questions

NaturalFarmer

Well-Known Member
Could you walk me through how do you calculate your C:N ratios please?
I'm just beginning to, and am thus very curious how others do it :-P
I think in terms of composting and gauging C:N ratios most consider carbon sources as the brown inputs like dead leaves and N inputs are your green like freshly cut grass.
 

calliandra

Well-Known Member
I don't actually but I do know that microbes oxidize carbon at a ratio of 100:10:1 C:N;P so I try to keep a level higher by large amounts than that. I don't think this should necessarily be looked at as compost because it is not.
Peat moss= high carbon
soybean meal=Nitrogen and P
Bone char= high carbon/high P
Rice hull= Carbon
Dead leaves(forgot to mention)=carbon
EWC=microbes
Wood ash= carbon pH adjust

If your N is too high you will get nitrifying bacteria producing ammonia overload in the first few weeks.

This mix has higher amounts of N and P than I used in the past, so I dont know exactly what to expect.
Ah OK thank you.
But if you're roughing the input C:N, how then can you know you have a C:N of 50?

I think in terms of composting and gauging C:N ratios most consider carbon sources as the brown inputs like dead leaves and N inputs are your green like freshly cut grass.
Yeah sorry, my question was too unspecific - I reformulated more precisely in my answer to IHearAll: https://www.rollitup.org/t/experienced-organic-grower-to-answer-your-questions.926327/page-7#post-13166675
 

iHearAll

Well-Known Member
Ah thanks for that link, I had been on that site hunting for C:N values, but hadn't actually read into it. Seems like a sensible approach there!

Sorry, I should've been more specific regarding my question :D

The C:N table I've been using is this one: http://www.carryoncomposting.com/416920203
The problem with those is that every organic material will have varying C:N values depending. So intuitively, I can understand that grass will be higher in N in springtime than in autumn, but how much higher? Since there can be quite a wide range of variance, even guesstimating seems really difficult!
So how do you decide, "ok these grass clippings (which can be anywhere between 9-25:1) have lots of clover in them and it's spring, so the C:N ratio is ..."

And what about ingredients I have no C:N for?
Is there any way we can extrapolate it if we only have the N value (then we could also use the NPK lists...), or should we just compare the material in question with something botanically similar and use that?

Ah and then there's also the problem of mixed ingredients - how much straw (75-100) is really mixed into that sheep manure (13-20)?! How does one assess this?

And after all that is resolved, I am not sure how to do the math to find the average, though I know I used to, which is totally unnerving! :shock:
To find your new ratio you can do a math equation. Ex. 1 part manure and 2 parts carbon would simply dilute the ratio of nitrogen. By how much? If your volumes are the same then chicken manure@ 10:1 would become 30:1. It was diluted twice using the same material so C is multiplied by two.

if you are salvaging materials from a farm you can fudge your numbers based on mass. if you have straw mixed in sheep manure, try to observe how much mass (by volume and density) are of each material. change your numbers accordingly. if you fin there isnt much straw, just change C by adding one or two. but if its cut 1:1 then add C.+C:N.+N

but that's assuming you arent cutting with any amount of nitrogen.

or maybe you are using a mix that is (C./3)+C : (N./3)+N

C. is the value of one carbon whule C is te value of the other. i just added a period to show they're different.

if you dont know what it's value is, observe its color, its material, it's smell. if it's green, treat it like fresh leaves. if its a meal, treat it as if it were hot like chicken manure and compost it or dilute it as a granular nutrient.


errr ....get it?
 

iHearAll

Well-Known Member
if it has a range of CN listed on a graph than take it for what it's worth and pick a number based on freshness, smell, experience. play around and make things too hot every so often. It'll be fun in the least and educational to a degree
 

ttystikk

Well-Known Member
I think the soy still needs a few weeks to break down but other than that, I would think so. Not sure if i understood your question.
The question is whether I can make the prescribed mix and immediately put plants in it, or if I need to wait for it to cook first.
 

NaturalFarmer

Well-Known Member
The question is whether I can make the prescribed mix and immediately put plants in it, or if I need to wait for it to cook first.
Yeah no problems. The fungi needs a few days to get started. I just wouldn't start with seedlings until the soy breaks down......or at least plant it in straight peat in the middle so the soy doesn't burns the roots. It will if it is in direct contact.
 

ttystikk

Well-Known Member
Yeah no problems. The fungi needs a few days to get started. I just wouldn't start with seedlings until the soy breaks down......or at least plant it in straight peat in the middle so the soy doesn't burns the roots. It will if it is in direct contact.
My girls are three feet tall when I pot them up into their final containers. They have a well developed 1 gallon root ball when they move, and up to 6 weeks to grow into the new container before bloom.
 

NaturalFarmer

Well-Known Member
My girls are three feet tall when I pot them up into their final containers. They have a well developed 1 gallon root ball when they move, and up to 6 weeks to grow into the new container before bloom.
You would be fine I believe. Have you tried planting in square pots (tote) to get more volume out of your space? I would shoot for no less than 15 gal pot but its worth a shot smaller if you can't fit it.
 

ttystikk

Well-Known Member
You would be fine I believe. Have you tried planting in square pots (tote) to get more volume out of your space? I would shoot for no less than 15 gal pot but its worth a shot smaller if you can't fit it.
Currently running 5 gallon buckets, I hear you implying that's not going to be big enough.

I'm planning a SIPS approach to maximize availability of water to my plants.
 

calliandra

Well-Known Member
To find your new ratio you can do a math equation. Ex. 1 part manure and 2 parts carbon would simply dilute the ratio of nitrogen. By how much? If your volumes are the same then chicken manure@ 10:1 would become 30:1. It was diluted twice using the same material so C is multiplied by two.

if you are salvaging materials from a farm you can fudge your numbers based on mass. if you have straw mixed in sheep manure, try to observe how much mass (by volume and density) are of each material. change your numbers accordingly. if you fin there isnt much straw, just change C by adding one or two. but if its cut 1:1 then add C.+C:N.+N

but that's assuming you arent cutting with any amount of nitrogen.

or maybe you are using a mix that is (C./3)+C : (N./3)+N

C. is the value of one carbon whule C is te value of the other. i just added a period to show they're different.

if you dont know what it's value is, observe its color, its material, it's smell. if it's green, treat it like fresh leaves. if its a meal, treat it as if it were hot like chicken manure and compost it or dilute it as a granular nutrient.


errr ....get it?
Yeah I went and played with it, and I do think I have!
So actually, we just need to multiply the C:N of each ingredient by its portion of the total, and add them all up. haha!
Noo idea anymore what I was agonizing over to make it seem so complicated :rolleyes:
So big thanks for getting me unstuck there! :mrgreen:
 

greasemonkeymann

Well-Known Member
I do not feel put down at all! Not knowing what I do or how I do it, it may behoove you to ask me more pertinent questions, as I do not understand your prognosis on 'layering' (your definition may be different than mine).

Honestly, I never heard of layering until you mentioned it.

What I do for my 'black thumbs' is give them a completely balanced soil blend that I make on my own. I then put that in an air pot and put a top soil layer of my homemade EWC and wood chip mulch that I make on my own.

In my experience, it is a fantastic way to help people that do not have experience growing. Their finished plants look quite good and they all are very happy.
well now i'm confused, are you two different people?
Below, you said you understand it, and acknowledge it has merits
while the above post contradicts that.
so I am confused

All good. I understand your sentiments. Though I am not as averse to concentrated layering, I do understand its pitfalls and its merits.

I tend to make my own soil for canna and recycle it after. Mixed in with enzyme, compost and worm teas, I really don't do much at all as far as replacing soil, etc. I make my own EWC as well, so that aids in the recycling soil aspect.
 

greasemonkeymann

Well-Known Member
@greasemonkeymann what happens with layering? I don't really know what it is. Any threads on it? Is this compost layering?
nah man, it's the whole premise behind subcools "supersoil", kindsoil, and a couple other nut-swingers
they use a bunch of water soluble nutrients, and make a layer of higher amounts of these at the bottom of the container, the premise is that the plant will have nutrients at a later date because it's "stored" there.
in reality the nutrients are not only water soluble (washed away quickly), but also the concentration amounts are so high that the soil is typically anaerobic, and acidic.
also plants don't work like that anyways, cannabis is a drought tolerant plant with massive roots, and after transplanting into a conducive soil the plant will shoot the roots to the bottom of the container within days, sometimes hours, so the "nutrients for later" idea is severely flawed.
In my experience if you want to do a grow like that you would be lightyears ahead by simply making a soil that has a good mix of dry meals all staggered in their availability, slow, medium, and fast release.
an example would be for nitrogen
fast release would be alfalfa meal, fish meal, etc. Neem meal
medium would be crab or shrimp meal, etc
slow would be hoof meal, doghair, feather meal, etc

the problem is in the subcool subsection there is a sticky on the soil mix and technique, and often new organic growers go to that first, and then end up pissed that their plants don't do well
 

calliandra

Well-Known Member
Yeah that makes sense. Never heard of it:) Thanks. Definitly sounds like some stoner logic involved.
Actually, it shows a hybrid situation of trying to be organic but still thinking chemically ;) It's very common in the wild nowadays and spews the most interesting "theories" about how things should be done lmao

When Grease speaks of slow release ingredients, it's not like what's in them then oozes out slowly, it's microorganisms taking them apart and eventually making the nutrients available for the plant to intake.
 
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