Research papers on N, P, K levels

[N1ghtL1ght]

It would be a way to reduce N (& Ca) by just adding some P, K, Mg & S to the normal mix
Some don't want to harvest green but yellow.

 

[BehindEnemyLines]

I found this really interesting…

Phosphorous, Flowering growth.
“Cannabinoid concentrations decreased linearly with increasing yield, consistent with a yield
dilution effect, but the total cannabinoid content per plant increased with increasing P supply. These results
reveal contrasting trends for effects of P supply on cannabinoid concentrations that were highest under <30
mg L P, vs. inflorescence biomass that was highest under 30–90 mg L P.”

Do you want concentrated cannabinoids and less yield, or more totals cannabinoids and yield?

 

[growsince79]

I found this really interesting…

Phosphorous, Flowering growth.
“Cannabinoid concentrations decreased linearly with increasing yield, consistent with a yield
dilution effect, but the total cannabinoid content per plant increased with increasing P supply. These results
reveal contrasting trends for effects of P supply on cannabinoid concentrations that were highest under <30
mg L P, vs. inflorescence biomass that was highest under 30–90 mg L P.”

Do you want concentrated cannabinoids and less yield, or more totals cannabinoids and yield?

I want less yield and best buds.

 

[BehindEnemyLines]

I want less yield and best buds.

I tend to agree with this.

What if for example someone intends to turn 100% of the product into concentrate, would that person then prefer increased total cannabinoids and yield?

 

[BehindEnemyLines]

Another note,

I started comparing the scientific studies NPK elemental concentrations vs. JACKS 3-2-1 elemental concentration and this is what I found:

JACKS 3-2-1:
N - 150 ppm
P - 52.35 ppm
K - 215.85

 

[CertifiedRefugee]

Another note,

I started comparing the scientific studies NPK elemental concentrations vs. JACKS 3-2-1 elemental concentration and this is what I found:

JACKS 3-2-1:
N - 150 ppm
P - 52.35 ppm
K - 215.85

View attachment 1282533
View attachment 1282534

yelp Thas about what you get when you put the numbers in Hydro buddy almost spot on

 

[Bluebuddha]

So the research says 160-50-175.

So ..Jack's. lol

 

[BehindEnemyLines]

So the research says 160-50-175.

So ..Jack's. lol

Yes, and that is using this feed schedule.

 

[Glomus]

Interesting the N and P are the same for Flowering and Veg. Also with the K, I think potassium over doses looks like cal mag deficiency sometimes.

 

[N1ghtL1ght]

Also with the K, I think potassium over doses looks like cal mag deficiency sometimes.

Yes it's true. A lot of toxicities display a deficiency via a lockout as well

 

[CertifiedRefugee]

that's why the research states that it various from cultivar to cultivar that why you can give one cultivar 200ppm of k its shows signs of toxicity and next one 200ppm of k it looks perfectly fine ...I can tell a lot of ppl or not reading the article or simply reading it but not understand it .it not new ...Med-Tek this guy
https://manicbotanix.com been talking about this for a while and he has posted all the articles and links to a lot of research and information all things related cannabis and ware he got it from if i remember correctly i think the study above was done in Israel

 

[mysticepipedon]

Why no just write it ml/L then? So 160 mgL-1 is 160 mg/L, right? Is this a European thing or something like that?

They started using the -1 exponent in scientific literature to mean "per" many decades ago. It probably had to do with the way equations looked when typewritten.

 

[CertifiedRefugee]

covert mgL-1 too ppms

Home / Concentration - Solution Conversion / Convert Milligram/liter to Part/million (ppm)

Convert Milligram/liter to Part/million (ppm)​

Please provide values below to convert milligram/liter [mg/L] to part/million (ppm), or vice versa.

​

From:​		milligrams/litres
To:​		part/million (ppm)
	​

Milligram/liter to Part/million (ppm) Conversion Table​

Milligram/liter [mg/L]​	Part/million (ppm)
0.01 mg/L​	0.010011423 part/million (ppm)
0.1 mg/L​	0.1001142303 part/million (ppm)
1 mg/L​	1.001142303 part/million (ppm)
2 mg/L​	2.002284606 part/million (ppm)
3 mg/L​	3.003426909 part/million (ppm)
5 mg/L​	5.005711515 part/million (ppm)
10 mg/L​	10.01142303 part/million (ppm)
20 mg/L​	20.02284606 part/million (ppm)
50 mg/L​	50.05711515 part/million (ppm)
100 mg/L​	100.1142303 part/million (ppm)
1000 mg/L​	1001.142303 part/million (ppm)

 

[CertifiedRefugee]

How to Convert Milligram/liter to Part/million (ppm)​

1 mg/L = 1.001142303 part/million (ppm)
1 part/million (ppm) = 0.9988590004 mg/L

Example: convert 15 mg/L to part/million (ppm):
15 mg/L = 15 × 1.001142303 part/million (ppm) = 15.017134545 part/million (ppm)

 

[CertifiedRefugee]

and yes mg/l and mgL-1 or the same...

 

[effexxess]

WEBINAR.
Advances in cannabis cultivation techniques: The power of mineral nutrition, lighting & plant structure
by Nirit Bernstein

Excerpts below:

So our experiments were divided for the vegetative growth separately from the reproductive growth


Nitrogen

"... range of nitrogen concentration from 30 ppm all the way up to 320 ppm milligram
per liter

look at it so what we recommend at least from those experiments but what we came out is for the vegetative stage 160 ppm

for the cultivation for the flowering stage
if we look under 30 ppms the plants were reduced in weight there was chlorosis which demonstrates nitrogen deficiency.

About 160 the plant looks great
however you know that when we actually checked secondary metabolic production the plants that gave us the highest concentration of most cannabinoids and most terpenes were those suffering hungry nitrogen hybrid plants that received 30 ppm nitrogen"



Potassium

"... We checked five different treatments of potassium 15 ppm all the way up to 240 ppm

vegetative growth set during veg that 15 is on the low side 60 is kind of
borderline and from 100 to 175 gave us the best biomass production and physiological function

what happened again to cannabinoids similar to what happened in nitrogen that under the deficiency contribution of 15 ppm or even 60 ppm where the plants were smaller and suffering from deficiency we actually receive the highest concentration of cannabinoids.

So for example if we look at this, THCA was reduced greatly was much higher under deficiency condition than under higher concentration

there's no reason to go above 100 ppm [of potassium] especially that we are risking reducing cannabinoids and terpenes"



Phosphorus

"... We checked five concentration of phosphorus in this case cannabis is indeed unique in a way

we really saw a very wide optimum range for potassium nutrition in cannabis. We definitely did not see any toxicity but also we did not see any benefit to going above about 30 ppm.

from 5 to 90 ppm phosphorus
again what we've seen is very similar to what we've seen for a nitrogen and potassium. That actually highest concentration of secondary metabolite was on these plants that suffered from phosphorus deficiency.

So yield the weight the biomass of the flowers were
not affected in concentration above 30 ppm or maybe a little bit more maybe 60ppm

So if we go from 5 to 90 we can see considerable reduction in cannabinoid concentration and this is the same for THC concentration

it really depends on the growers preference if we are going for larger biomass then probably we're going for a middle range kind of concentration 30 ppm or maybe slightly above it up to 60 ppm"


"We are developing breakthrough technologies in order to
fool the plants to think that they are under deficiency or under some kind of deficiency nutrient stress condition without actually compromising plant development"