Nutrients Journal Articles - Cannabis Nutrient Optimization

[Bruce Campbell]

If anyone is looking for some light reading, here's a list of articles I've found on optimal nutrient levels for cannabis.

If anyone knows of any others, please let me know. A few notes:

• These are mainly limited to academic / peer-reviewed articles and studies. I'm trying not to include articles from blogs, marketing materials, trade publications, etc unless they have ties to academic institutions or similar pedigree.
• So far, limited to open-access / publicly available articles. There may be some missing from the list if they are behind paywalls (e.g., Elsevier, Wiley, etc).
• There may be some articles focusing on industrial hemp (i.e., CBD / low-THC) studies included in the list right now

Title	Authors	Publication	Date	Link
Optimization of N, P, K for soilless production of Cannabis sativa in the flowering stage using response surface analysis	Bevan, Jones, Zheng	Preprint / Not Peer Reviewed	Aug-2021	https://www.preprints.org/manuscript/202108.0460/v1
Response of essential oil hemp (Cannabis sativa L.) growth, biomass, and cannabinoid profiles to varying fertigation rates	Anderson, Brian Pearson, Kjelgren, et al	PLoS ONE 16(7): e0252985.	Jul-2021	https://doi.org/10.1371/journal.pone.0252985
The Highs and Lows of P Supply in Medical Cannabis: Effects on Cannabinoids, the Ionome, and Morpho-Physiology	Shiponi, Bernstein	Front. Plant Sci., 15	Jul-2021	https://doi.org/10.3389/fpls.2021.657323
Magnesium’s Impact on Cannabis sativa ‘BaOx’ and ‘Suver Haze’ Growth and Cannabinoid Production	Veazie, Cockson, Logan, et al	JAHR: Vol. 2 : Iss. 2 , Article 1	May-2021	https://digitalcommons.murraystate.edu/jahr/vol2/iss2/1/
Elevated Phosphorus Fertility Impact on Cannabis sativa ‘BaOx’ Growth and Nutrient Accumulation	Veazie, Cockson, Kidd, et al	IJISET, Vol. 8 Issue 2	Feb-2021	http://ijiset.com/vol8/v8s2/IJISET_V8_I02_32.pdf
Augmenting Nutrient Acquisition Ranges of Greenhouse Grown CBD (Cannabidiol) Hemp (Cannabis sativa) Cultivars	Kalinowski, Edmisten, Davis, et al	Horticulturae 2020, 6, 98	Dec-2020	https://www.mdpi.com/2311-7524/6/4/98
Response of Medical Cannabis (Cannabis sativa L.) to Nitrogen Supply Under Long Photoperiod	Saloner, Bernstein	Front. Plant Sci., 17 November 2020	Nov-2020	https://www.frontiersin.org/articles/10.3389/fpls.2020.572293/full
Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes	Cockson, Schroeder-Moreno, Veazie, et al	Appl. Sci. 2020, 10, 7875	Nov-2020	https://www.mdpi.com/2076-3417/10/21/7875
Balancing the Nutrient Equation in Cannabis Cultivation	Whipker, Cockson, Veazie, et al	Cannabis Business Times	Jun-2020	https://www.cannabisbusinesstimes.com/article/balancing-the-nutrient-equation-cannabis-cultivation/
Response of Medical Cannabis (Cannabis sativa L.) Genotypes to K Supply Under Long Photoperiod	Saloner, Sacks, Bernstein	Front. Plant Sci., 18	Nov-2019	https://doi.org/10.3389/fpls.2019.01369
Impact of N, P, K, and Humic Acid Supplementation on the Chemical Profile of Medical Cannabis (Cannabis sativa L)	Bernstein, Gorelick, Zerahia, et al	Front. Plant Sci. 10:736.	Jun-2019	https://www.frontiersin.org/articles/10.3389/fpls.2019.00736/full
Optimal Rate of Organic Fertilizer during the Flowering Stage for Cannabis Grown in Two Coir-based Substrates	Caplan, Dixon, Zheng	HORTSCIENCE 52(12):1796–1803. 2017.	Dec-2017	https://journals.ashs.org/hortsci/view/journals/hortsci/52/12/article-p1796.xml
Industrial Hemp Response to Nitrogen, Phosphorus, and Potassium Fertilization	Aubin, Seguin, Vanasse, et al	CFTM 2015	Nov-2015	https://acsess.onlinelibrary.wiley.com/doi/full/10.2134/cftm2015.0159

 

[Bruce Campbell]

Thanks @Mañ'O'Green

Slowly making my way through them...

 

[Bruce Campbell]

Couple updates:

First, updated table - added a few, added numbers for reference, classified between Hemp (CBD / < 0.3% THC) and Marijuana (> 0.3% THC). Removed "industrial hemp" articles (i.e., those focusing on fiber or stem aspects of hemp and not CBD aspects of hemp).

Number	Hemp / Marijuana	Title	Authors	Publication	Date	Link
1	M	Optimization of N, P, K for soilless production of Cannabis sativa in the flowering stage using response surface analysis	Bevan, Jones, Zheng	Preprint / Not Peer Reviewed	Aug-2021	https://www.preprints.org/manuscript/202108.0460/v1
2	H	Response of essential oil hemp (Cannabis sativa L.) growth, biomass, and cannabinoid profiles to varying fertigation rates	Anderson, Brian Pearson, Kjelgren, et al	PLoS ONE 16(7): e0252985.	Jul-2021	https://doi.org/10.1371/journal.pone.0252985
3	M	The Highs and Lows of P Supply in Medical Cannabis: Effects on Cannabinoids, the Ionome, and Morpho-Physiology	Shiponi, Bernstein	Front. Plant Sci., 15	Jul-2021	https://doi.org/10.3389/fpls.2021.657323
4	H	Magnesium’s Impact on Cannabis sativa ‘BaOx’ and ‘Suver Haze’ Growth and Cannabinoid Production	Veazie, Cockson, Logan, et al	JAHR: Vol. 2 : Iss. 2 , Article 1	May-2021	https://digitalcommons.murraystate.edu/jahr/vol2/iss2/1/
5	H	Elevated Phosphorus Fertility Impact on Cannabis sativa ‘BaOx’ Growth and Nutrient Accumulation	Veazie, Cockson, Kidd, et al	IJISET, Vol. 8 Issue 2	Feb-2021	http://ijiset.com/vol8/v8s2/IJISET_V8_I02_32.pdf
6	H	Augmenting Nutrient Acquisition Ranges of Greenhouse Grown CBD (Cannabidiol) Hemp (Cannabis sativa) Cultivars	Kalinowski, Edmisten, Davis, et al	Horticulturae 2020, 6, 98	Dec-2020	https://www.mdpi.com/2311-7524/6/4/98
7	M	Response of Medical Cannabis (Cannabis sativa L.) to Nitrogen Supply Under Long Photoperiod	Saloner, Bernstein	Front. Plant Sci., 17 November 2020	Nov-2020	https://www.frontiersin.org/articles/10.3389/fpls.2020.572293/full
8	H	Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes	Cockson, Schroeder-Moreno, Veazie, et al	Appl. Sci. 2020, 10, 7875	Nov-2020	https://www.mdpi.com/2076-3417/10/21/7875
9	M	Balancing the Nutrient Equation in Cannabis Cultivation	Whipker, Cockson, Veazie, et al	Cannabis Business Times	Jun-2020	https://www.cannabisbusinesstimes.com/article/balancing-the-nutrient-equation-cannabis-cultivation/
10	M	Response of Medical Cannabis (Cannabis sativa L.) Genotypes to K Supply Under Long Photoperiod	Saloner, Sacks, Bernstein	Front. Plant Sci., 18	Nov-2019	https://doi.org/10.3389/fpls.2019.01369
11	M	Impact of N, P, K, and Humic Acid Supplementation on the Chemical Profile of Medical Cannabis (Cannabis sativa L)	Bernstein, Gorelick, Zerahia, et al	Front. Plant Sci. 10:736.	Jun-2019	https://www.frontiersin.org/articles/10.3389/fpls.2019.00736/full
12	M	Optimal Rate of Organic Fertilizer during the Flowering Stage for Cannabis Grown in Two Coir-based Substrates	Caplan, Dixon, Zheng	HORTSCIENCE 52(12):1796–1803. 2017.	Dec-2017	https://journals.ashs.org/hortsci/view/journals/hortsci/52/12/article-p1796.xml
13	M	Optimal Rate of Organic Fertilizer during the Vegetative-stage for Cannabis Grown in Two Coir-based Substrates	Caplan, Dixon, Zheng	HORTSCIENCE 52(9):1307–1312. 2017.	Sep-2017	https://journals.ashs.org/hortsci/downloadpdf/journals/hortsci/52/9/article-p1307.xml
14	M	How Does Your Cannabis Fertilizer Recipe Compare?	Whipker, Cockson, Veazie, et al	Cannabis Business Times	Feb-2021	How Does Your Cannabis Fertilizer Recipe Compare? Researchers compared three fertilizer programs to determine how much of each nutrient cannabis really needs. www.cannabisbusinesstimes.com

		Closed Access
A1	M	Responses of Greenhouse-grown Cannabis sativa L. to Nitrogen, Phosphorus, and Potassium	C. B. Coffman,W. A. Gentner,		Sep-1977	https://doi.org/10.2134/agronj1977.00021962006900050026x
A2	M	Cannabinoid Profile and Elemental Uptake of Cannabis sativa L. as Influenced by Soil Characteristics	C. B. Coffman,W. A. Gentner,		Jul-1975	https://doi.org/10.2134/agronj1975.00021962006700040010x
A3	M	Nitrogen supply affects cannabinoid and terpenoid profile in medical cannabis (Cannabis sativa L.)	Saloner, Bernstein		Sep-2021	https://doi.org/10.1016/j.indcrop.2021.113516

 

[Bruce Campbell]

Second:

Made my way through all the articles. Attached are the KDawg's Notes version summarizing each article, if anyone wants to know details.

 

[Bruce Campbell]

Third:

Here's the main takeaways from the current research:

• Research Teams - Bernstein and Saloner (Israel) seem to be doing the most useful and rigorous trials. NCSU (Cockson, Veazie, et al) seem to be the only ones doing research in the US, but seem to be primarily focused on CBD Hemp (likely due to federal funding restrictions). However, they make a good deal of assumptions from past research on ornamental flowers, and their experimental design and methodology can be a bit lacking. Caplan and Dixon (Canada) are in-between the two, relatively decent results, but can vary in some details which require you to interpret / adjust their results for other conditions. Anything with Zheng (China) seems to be outstanding. But, for some reason, are often published without peer review.
• Nitrogen (General) - There's evidence that it can be best to continue nitrogen use during flower to optimize total THC / plant. Low vs. high nitrogen is basically a trade-off of higher THC in main buds, but lower mass of buds overall vs. lower THC / higher overall mass of buds. There's an optimum somewhere in the middle of total combined THC / plant. Overall, should be tailored to what you want out of the harvest (e.g., concentrate extraction, dankest possible main cola, etc).
• Phosphorous (General) - Main consensus is that growers and popular fertilizers use way more phosphorous than needed. It's more a concern for commercial cultivation to reduce environmental effects of phosphate run-off. But, results are showing that potency / yield plateau and there's no benefit above a certain level. Cannabis tends to store P in the roots during veg, then use that first before taking extra P from soil during flowering. Still, seems to be a reasonably high limit on P toxicity.
• Potassium (General) - Looks to be no significant effect on potency / yield, as long minimums are met. However, the relationship seems to be more cultivar-specific than N and P. Potassium is mainly used in side and lateral branches, so it's likely needed more / more beneficial for bushier cultivars. Would be interesting to see if it's more useful for plants that are LST / topped. Seems to be a pretty broad sufficiency range between deficient and toxic levels.
• Ratios (N/P/K) - Most of the research trials only vary a single nutrient. There hasn't been a trial that specifically evaluates ratios. For base feed formulas (i.e., nutrients other than those being varied), researchers will often use similar macro/secondary/micro concentrations between their own studies. But, the base feed can vary significantly among researchers.
• Ratios (K/Ca/Mg) - Antagonism between K/Ca/Mg has been mentioned a few times, but not specifically evaluated. The closest is a recommendation from the NCSU team based on poinsettia cultivation to use a 4:2:1 ratio of K:Ca:Mg to limit antagonisms.
• Results May Vary - Most studies use only one or two cultivars. The general nutrient trends should be mostly similar, but exact optimums may vary. CBD Hemp results should be roughly applicable to THC Marijuana cultivation during vegetative stage, but less so during flowering. All studies are based on photoperiod and indoor cultivation, and optimum levels for autoflowers may be less than those for photoperiods.
• Fertilizer Types and Units -Optimum rates using organic (i.e., carbon-containing) liquid fertilizers can be higher than synthetic salts since organics are slower-releasing. Units reported below are elemental ppm values. Be aware that label values can be based on molecular concentrations (e.g., especially for phosphates and potash) and may need to be converted to elemental concentrations.

So, here's the main results:

• Optimum Nitrogen - Bernstein / Saloner found that 160 ppm N was the optimal range for vegetative, and also provided the optimal total plant THC during flowering. Deficiency occured at <15-30 ppm N; Root restriction began at 240 ppm N; Coloration was not affected until 320 ppm N. Canada found higher rates to be optimal in coco, but these were based on organic fertilizers and may have included slight CO2 enrichment. Zheng found that 189 ppm N was optimal based on statistical analysis.
• Optimum Phosphorous - Bernstein / Saloner found that < 15 ppm P resulted in deficiency, and 30 - 90 ppm P provided essentially similar results. No toxicity was observed up to 90 ppm P. The range of P levels tested by Canada did not provide any additional info (i.e., either too low and/or too broad). Zheng found that 60 ppm P was optimal from statistical analysis.
• Optimum Potassium - Bernstein / Saloner found that deficiency occured at < 15 ppm K. Overall, K had no significant impact on growth metrics over most of the range studied and did not cause significant toxicity at 245 ppm K. 245 ppm K slightly reduced growth metrics for one cultivar, but increased lateral growth for another cultivar. Canada did not specifically evaluate K, and Zheng found no significant statistical yield dependency on K.

 

[Death The Cultivator]

Beautiful! I've been reading through these all weekend

 

[Bruce Campbell]

Beautiful! I've been reading through these all weekend

Awesome! Let me know your thoughts....they can be pretty hard to digest, so I could use a second opinion

 

[Bruce Campbell]

Added another article to the list:

15

H

Characterization of Nutrient Disorders of Cannabis sativa

Cockson, Landis, Whipker, et al

Appl. Sci. 2019, 9, 4432

Oct-2019

https://www.mdpi.com/2076-3417/9/20/4432

It's not specifically about optimal nutrient levels, but I still find it a useful reference. It's from the NCSU team and provides examples of nutrient disorders in hemp cannabis. The images are low-res and not as good as those in the AFN infirmary forum, but it does a good job of discussing progression of symptoms.

 

[Bruce Campbell]

Was curious how my micro-nutes in my feed compared to those in the studies, so I put together the table below.

It provides the wt ppm (mg/L) of the nutrients used from some of the studies. Some studies didn't report all details of their feed. Others reported amounts of fertilizer brands, and I have not converted yet. The amounts below are from studies that specifically listed each nutrient.

Besides macronutrients (N/P/K), the studies did not evaluate or attempt to optimize secondary and/or micronutrients. So, these should be considered general or representative sufficiency levels that did not result in deficiency or toxicity.

Notes:
1) The amounts below are elemental ppm values converted from molar concentrations published in the studies.
2) "N/R" = Not Reported for the study.

			PPM ( = mg/L)
Number	Hemp / Marijuana	Title	Stage	N	P	K	Ca	Mg	Na	Cl	S	Co	Cu	Fe	Mo	Zn	B	Si	Mn
10	M	Response of Medical Cannabis (Cannabis sativa L.) Genotypes to K Supply Under Long Photoperiod	Veg	230	59	15 - 240	120	35	24	13	N/R	N/R	N/R	1.68	N/R	0.33	N/R	N/R	1.10
7	M	Response of Medical Cannabis (Cannabis sativa L.) to Nitrogen Supply Under Long Photoperiod	Veg	30 - 320	59	200	45	45	75	91	89	N/R	0.04	1.68	0.03	0.39	0.10	N/R	0.77
3	M	The Highs and Lows of P Supply in Medical Cannabis: Effects on Cannabinoids, the Ionome, and Morpho-Physiology	Flower	175	5 - 90	100	120	35	N/R	2.13	47	N/R	0.05	1.17	0.03	0.33	0.10	N/R	0.60
5	H	Elevated Phosphorus Fertility Impact on Cannabis sativa ‘BaOx’ Growth and Nutrient Accumulation	Veg	150	15 - 180	150	125	45 - 90	N/R	N/R	54	N/R	0.2	4	0.01	0.2	0.50	N/R	1.00
1	M	Optimization of N, P, K for soilless production of Cannabis sativa in the flowering stage using response surface analysis	Both	70 - 290	20 - 100	60 - 340	130 - 260	45	N/R	5 - 190	180	N/R	0.03	2.1	0.018	0.12	0.39	N/R	0.60
15	H	Characterization of Nutrient Disorders of Cannabis sativa	Veg	210	31	235	200	49	N/R	N/R	64	N/R	0.19	4	0.01	0.2	0.49	N/R	0.99

 

[Bruce Campbell]

Another article for the list:

16

N/A

How to Select the Right Fertilizer for Hydroponics

Langenhoven

Greenhouse and Indoor Hydroponics Workshop

Sep-2018

https://www.purdue.edu/hla/sites/cea/wp-content/uploads/sites/15/2018/10/PetrusLangenhoven9-5-18.pdf

It's the source of nutrient ranges in MoG's Nutrient tutorial. It's for general hydroponics and not cannabis specific, but provides good background. Added to the list because I'll refer to the general ranges in there for comparison to what the cannabis-specific studies use.