NPK research by Nirit Bernstein

[effexxess]

NPK in vegetative, growth stage: 160/30/175 mg L
NPK in flowering stage: 160/60/60 mg L

Here's a roundup of recent research done expressly on medical THC cannabis. Wondering how to interpret the recommendations?

For instance, is a NPK of 160/30/175 mg L equal to 10/2/12?
Does 160/60/60 equal 10/4/4?

I'm posting a list of links to NPK research by Nirit Bernstein, from the Institute of Soil, Water and Environmental Sciences, Volcani Center, Israel.

Medical Cannabis recommended N, P, K levels from Volcani Center research:
N veg: Response of Medical Cannabis to Nitrogen Supply Under Long Photoperiod (2020)
P veg: Response of medical cannabis genotypes to P supply under long photoperiod: Functional phenotyping and the ionome (2021)
K veg: Response of Medical Cannabis Genotypes to K Supply Under Long Photoperiod (2019)
N flower: Nitrogen supply affects cannabinoid and terpenoid profile in medical cannabis ( Flowering phase 2021)
P flower: The Highs and Lows of P Supply in Medical Cannabis: Effects on Cannabinoids, the Ionome, and Morpho-Physiology (2021)
K flower: Effect of Potassium (K) Supply on Cannabinoids, Terpenoids and Plant Function in Medical Cannabis (2022)

 

[Moe.Red]

Thanks for the links. Welcome to the farm.

 

[effexxess]

Thanks Moe.Red! Happy to join the farm.

The NPK research suggests veg 10/2/12 and flower at 10/4/4. Thoughts anyone?

 

[Moe.Red]

There was some research done suggesting that yield goes up but THC goes down when you feed lots of N. But it was done at much higher levels of N and outdoors in crop style. Makes me wonder tho if 10/4/4 in flower is too high?

Impact of Nitrogen Nutrition on Cannabis sativa: An Update on the Current Knowledge and Future Prospects

Nitrogen (N) availability represents one of the most critical factors affecting cultivated crops. N is indeed a crucial macronutrient influencing major aspects, from plant development to productivity and final yield of lignocellulosic biomass, as well ...

www.ncbi.nlm.nih.gov

that's not the study I was thinking of but it comes to some of the same conclusions. I'll try to dig up the link on the other one, It's on my PC.

 

[nashobaTHC]

The veg ratios might be ok but I really question the flowering ratio having N at 2.5 times P and K. Kinda flies in the face of most cannabis flowering nutrients showing significantly higher P and K than N. So once again it’s into the realm of conflicting grow information.

 

[mysticepipedon]

I'm finding a high demand for N in early flower, since going to LEDs. I don't know if it's a good idea to continue with high N for more than 2-3 weeks into flower, though.

 

[Oldchucky]

And does the water soluble versus the water insoluble ratio make a big difference?

 

[effexxess]

Some more from Dr Bernstein. This is a webinar presenting a summary of findings.



The audio volume is low.
.

 

[hydrodreams]

The veg ratios might be ok but I really question the flowering ratio having N at 2.5 times P and K. Kinda flies in the face of most cannabis flowering nutrients showing significantly higher P and K than N. So once again it’s into the realm of conflicting grow information.

Maybe we will start to realize the actual low level of expertise of traditional cannabis fertilizer companies the more the real scientist start to deal with this topic. Maybe.

 

[N1ghtL1ght]

Maybe we will start to realize the actual low level of expertise of traditional cannabis fertilizer companies the more the real scientist start to deal with this topic. Maybe.

I hope so. And more research on characteristics of malnutrition.