The Myth of Low N?

[desertsquirrel]

I remember first reading about the myth of high P in the late 90's and early 2000's. Ever since then i have been working on nutrient profiles; finding that indeed lower P with occasional boosts seemed to do far better. However i had this constant feeling that something else was off. Time and time again i found myself overly concerned with both N and cal/mag issues.

Recently i found myself more concerned then ever with my profiles as im taking over several rooms of Under Currents. In doing that work i calculated the numbers from both agriculture industry tissue samples as well as cannabis samples and was blown away by what i may have found. (i cant believe i never ran the numbers on these samples, i have had the doc for years). Anyway before i get too much into my conclusions, here is the work.... I should add the profiles are halved for undercurrents, and the spreads are in ppm and then ratios.

 

[desertsquirrel]

Initial observations....

The myth of low N. N almost doubles from Veg to flower according to the plant tissue samples. And while nearly all hydroponic nutrient lines provide (or seem to strive to provide) 100% of the ppm need for each mineral, N is provided at 60% its actual PPM need. Possibly look to Urea or multiple nitrates to fix this problem.

Higher calcium is needed for plant tissue production until stretch is complete.

cal levels half durring flower and mg doubles. Following stretch switch from cal-mag to to Epsom salts.

Keep S = with Mg

Low P with spikes 3 times beginning with stretch. (50/30 is in perfect ratio with the tissue analysis).

4% of the tissue in agri industry was supplemental minerals, w/about 8% for mmj. This cultivar uptakes twice as much as most.

 

[Seamaiden]

Whoa.... WHOA! So... you just helped me grasp what I had hit upon by accident when I switched from using Cal-Mag to 6%Ca (organic liquid product, 0%N) and MgSO4. WOW! And the S I hadn't even accounted for other than by its effect on EC!

Major thanks! :D

 

[Onespark]

YES! this is very very helpful. Thanks.

 

[Jalisco Kid]

It depends on your strain with N. My paki can feed on high ratios of N while some of my sats would roll their leaves and die on those ratios. I feel H&G takes to much N into late flowering for me. I have my clients using h&g run just b past week 4 getting better flavor and trics.JK

 

[UCMENOW]

Initial observations....

"The myth of low N. N almost doubles from Veg to flower according to the plant tissue samples. And while nearly all hydroponic nutrient lines provide (or seem to strive to provide) 100% of the ppm need for each mineral, N is provided at 60% its actual PPM need. Possibly look to Urea or multiple nitrates to fix this problem."

True that plants like corn, barley, potatoes and the such actually increase in over all yields per hectar/ acre when supplemntal N is provided. Though with MMJ a yield increase when N levels are elevated often comes with a far higher leaf to calyx ratio.

Undoubtedly, plants will grow larger as a result of being fed higher N levels....especially ammoniacal N, which is easily assimilated by plants. This larger leaf biomass can result in higher yields but also excessive chloraphyll production which (IMO) lends toward harsh herb. The presence of this N can also hinder the trigger of the reproductive cycle and prolong the flowering period of MMJ (especially in water culture which seems to make water soluble N more easily available).

"Higher calcium is needed for plant tissue production until stretch is complete."

Word.

"cal levels half during flower and mg doubles. Following stretch switch from cal-mag to to Epsom salts. Keep S = with Mg"

Magnesium sulfate for the win!

"Low P with spikes 3 times beginning with stretch. (50/30 is in perfect ratio with the tissue analysis)."

I'd be curious to see how green the plants were in peak flower vs. ripening and when the tissue sample was collected being referred to? I like the occasional P spike you're mentioning......though it seems in hydro, strong plant tissue (cell wall) production is aided by K as much as any other nute.

Cool thread DS, should be interesting to see what growers chime in with. I agree with JK on the H&G N ratio...sounds like the B only could be a good solution for that.

 

[Dynamite]

aren't those the same reports that Advanced Nutrients put out awhile back ?

I've ran across many products over the years that make the plants more green , or seem to feed the plant but not the buds - I'm not trying to grow leaf and stem

How the N directly impacts the bud production and quality is all that matters to me

 

[desertsquirrel]

What i am so interested in is this...

The numbers taken from plant tissue already show extreem levels of N. My question is how did this come about? Advanced Nutrients profile offers maybe 60% of the N found in the tissue that that profile was feeding. What does this mean? Was the solution simply being depleted of N faster? Does that mean 40% more solution was needed to be transpired to achive the 100% of N found in the plant? How much harder is the plant working to achive this? Does that also mean its over-uptaking 40% of the rest of the solution?

If N is already present in the plant tissue, the plants getting it. Why would altering the feeding to reflect what the plant is actually taking up result in more leaf and less bud? we are assuming big mike had good herb tested right? I will have alot more insight on this matter when i begin doing my own tissue samples this summer. I think leaf/stem/bud samples need to be done, among other things....

 

[Seamaiden]

Sled that is lead ---> molasses, FTW? Jesus, read the labels again, why don't I?

I've never yet been able to find a full nutrient profile for malted barley extract. I used that for an entire season and it turned out very well, may be a rather different product than molasses.

No pain, no pain! :D

 

[Snowblind]

Very interesting so far. What sort of elemental ppm ratios do you work with currently desertsquirrel?

When you spike your P, by how many ppm? I tend to maintain high K levels throughout my grows so far...

 

[desertsquirrel]

Snowblind, I posted some profile work as well as a side by side with pbp, cns17, and H&G profiles in a thread called "UC actual available nutrient profiles" in the undercurrent section. remember those profiles are halved because they are for the undercurrent....

Another great thread for profiles is shroomdrs thread on IC mag if your interested.

 

[IndicacannaJone]

Humboldt's Big Up Powder is a 0-33-23 that is to be used three times during bloom. Once at flip, and then twice toward the end of the cycle. Is the idea behind this the same thing you're outlining here? Granted, it's not 0-50-30, but it does have the higher P. I think Beastie Bloomz is the 50/30 ratio, along with some other PK boosters.

The magnesium... is this the idea behind a supplement like Bud Factor X? I'm trying to connect the dots, and wondering if these are the same ideas being used by nute companies, or am I off-base with what you're saying here?

 

[Seamaiden]

Maybe this will help you connect some of those dots, Jone.
Plant Nutrient Interactions.

 

[Snowblind]

Snowblind, I posted some profile work as well as a side by side with pbp, cns17, and H&G profiles in a thread called "UC actual available nutrient profiles" in the undercurrent section. remember those profiles are halved because they are for the undercurrent....

Another great thread for profiles is shroomdrs thread on IC mag if your interested.

Thanks for the info.....

 

[desertsquirrel]

Epsom profile:

im pretty sure this is correct, but im not 100%. Please let me know if the numbers are off.

Epsom salt, magnesium sulfate, Mgso4:

Mg: 9.8%
S: 13%

1g Epsom salt =

Mg: 98 mg or 98 ppm/liter
S: 130 mg or 130 ppm/liter

or

1g/10 liters =

Mg 9.8 ppm
S 13 ppm

 

[bloads]

It depends on your strain with N. My paki can feed on high ratios of N while some of my sats would roll their leaves and die on those ratios. I feel H&G takes to much N into late flowering for me. I have my clients using h&g run just b past week 4 getting better flavor and trics.JK

You completely forgo using any A? Do you taper off from normal feeding at beginning of flower, to no A at 4 weeks, or do you just turn it off all at once at four weeks?

Week four on all strains, or is that for a specific time-frame (8 week strain, 10 week strain, etc.)?

 

[Confuten1]

This thread Is great!! I feel like a kid in the candy store..

Oh, n thanks fir the visuals SEA. Im a visual learner.

Confu...

 

[jokalyx]

Pertinent reflexion and research

Thanks fpr documenting about such isuues. Very happy to learn more. Even if I have some problems to catch the meaning of all acronyms used in the thread.

BTW, could anyone tell me where one can score some molasses and kelps and under which form (liquid, powder, ...)and how much and how often it should be used, plz? I live in Germany. I am very grateful for your coming answers.

Sorry, I hope I am not switching or diverging from the core of his thread.

Thanks

 

[Green Mopho]

Good thread. I am interested in adjusting my H&G formula for more than one medium, myself. And I have noticed MUCH leafier plants since using H&G.

 

[Kobe24]

http://docs.google.com/viewer?a=v&q...JJzgIv&sig=AHIEtbQaF77v1f2n1ulQVCVzshzDhW377A