Uploaded August 2024 | Updated September 2026, 2 weeks ago
Impact of Organic and Mineral Based Fertilizers on Cannabis Yield
Professor DeBacco
Research Article
Massuela, D. C., Munz, S., Hartung, J., Nkebiwe, P. M., & Graeff-Hönninger, S. (2023). Cannabis Hunger Games: nutrient stress induction in flowering stage–impact of organic and mineral fertilizer levels on biomass, cannabidiol (CBD) yield and nutrient use efficiency. Frontiers in Plant Science, 14, 1233232.
frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1233232/full
Two Liquid Fertilize Types
Organic
Mineral solution
Both were prepared in order to contain the same concentration of macronutrients based on manufacture provided information.
Macronutrients: N, P, K, Ca, Mg were the main study focus.
*No signs or symptoms of micronutrient deficiencies or toxicities were observed between organic and mineral treatments.
Fertilizer Concentrations and Sequence
Concentrations studies were…
80 mg L−1
160 mg L−1
240 mg L−1
Fertilizer treatments were applied in liquid solution twice per week starting on 22 DAP.
See Supplementary Table 2 for details
Plants did not receive any further fertilizer during the last week of cultivation
Plant Sampling
Two harvests during the vegetative stage:
22 and 36 DAP
Four harvests during the flowering stage:
54, 69, 83, and 99 DAP
At each harvest, four plants per treatment (one plant per treatment and replicate) were cut at the base and separated into three fractions…
Stems
Leaves
Inflorescences
N-P-K Content of Leaves Compared to Flowers
Least square means (±standard error) for the content of (A, B) nitrogen, (C, D) phosphorus, and (E, F) potassium in leaves (left) and inflorescences (right) for the fertilizer concentrations (80, 160 and 240 mg N L−1) at different harvest dates (days after planting, DAP).
For each harvest date within each single figure, means with different letters were significantly different from each other according to Fisher’s LSD test with a=0.05.
Phosphorus Fertilization…
In this study, no significant differences between fertilizer concentrations were found for P concentration in inflorescences at the final harvest.
P concentration in leaves, stem and substrate were significantly higher for treatment 240 indicating overfertilization with P (240 in comparison to 160) at the flowering stage
Maintaining high nutrient levels in leaves and substrate is not relevant at the harvest point.
Mineral Fertilizers
Generally, mineral fertilizers show higher nutrient uptake and agronomic use efficiencies compared to organic treatments
Organic Fertilizers
The significantly lower plant and inflorescence dry matter, leaf area and finally CBD yield of organic treatments are supported by the general lower nitrogen uptake efficiency (especially in the last two weeks which is the major sink stage) compared to mineral treatments.
If Using Organic Fertilizers Consider...
Organic fertilizer should be applied earlier at a higher rate to be available during the final two weeks of flowering when the sink demand for inflorescences is very high.
Best of Both
The higher availability of mineral fertilizer can be important for plant initial growth, while organic fertilizers can be employed as a more sustainable nutrient complementation during flowering without major yield losses.
Fertilizer Concentration: Take Home Message
The fertilizer concentration 160 produced 95% of the CBD yield of 240, while receiving one-third less nutrients.
Organic Fertilizer Usage: Take Home Message
If using organic fertilizers you may have to add more than someone else using mineral based fertilizers because of the lower nutrient uptake efficiency.
Nutrient acquisition was lower for the organic fertilizer during the final two weeks before harvest, resulting in reduced biomass and CBD yield compared to mineral fertilizer treatments.
Phosphorus Fertilization: Take Home Message
The fertilizer rate of P can be in general reduced during end of flowering to avoid unproductive nutrient accumulation in vegetative plant organs.
Link to Lecture Slides: drive.google.com/file/d/1sVH1JsMbtAGr1zq6egKyGUYxzooJWcL8/view?usp=drive_link
*Due to the description character limit the full work cited for "Impact of Organic and Mineral Based Fertilizers on Cannabis Yield" can be viewed at... docs.google.com/document/d/1xA-5AiNzeR8QHwvruKjZOT5nPD1FohgU/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
Impact of Organic and Mineral Based Fertilizers on Cannabis Yield
Professor DeBacco
Research Article
Massuela, D. C., Munz, S., Hartung, J., Nkebiwe, P. M., & Graeff-Hönninger, S. (2023). Cannabis Hunger Games: nutrient stress induction in flowering stage–impact of organic and mineral fertilizer levels on biomass, cannabidiol (CBD) yield and nutrient use efficiency. Frontiers in Plant Science, 14, 1233232.
frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1233232/full
Two Liquid Fertilize Types
Organic
Mineral solution
Both were prepared in order to contain the same concentration of macronutrients based on manufacture provided information.
Macronutrients: N, P, K, Ca, Mg were the main study focus.
*No signs or symptoms of micronutrient deficiencies or toxicities were observed between organic and mineral treatments.
Fertilizer Concentrations and Sequence
Concentrations studies were…
80 mg L−1
160 mg L−1
240 mg L−1
Fertilizer treatments were applied in liquid solution twice per week starting on 22 DAP.
See Supplementary Table 2 for details
Plants did not receive any further fertilizer during the last week of cultivation
Plant Sampling
Two harvests during the vegetative stage:
22 and 36 DAP
Four harvests during the flowering stage:
54, 69, 83, and 99 DAP
At each harvest, four plants per treatment (one plant per treatment and replicate) were cut at the base and separated into three fractions…
Stems
Leaves
Inflorescences
N-P-K Content of Leaves Compared to Flowers
Least square means (±standard error) for the content of (A, B) nitrogen, (C, D) phosphorus, and (E, F) potassium in leaves (left) and inflorescences (right) for the fertilizer concentrations (80, 160 and 240 mg N L−1) at different harvest dates (days after planting, DAP).
For each harvest date within each single figure, means with different letters were significantly different from each other according to Fisher’s LSD test with a=0.05.
Phosphorus Fertilization…
In this study, no significant differences between fertilizer concentrations were found for P concentration in inflorescences at the final harvest.
P concentration in leaves, stem and substrate were significantly higher for treatment 240 indicating overfertilization with P (240 in comparison to 160) at the flowering stage
Maintaining high nutrient levels in leaves and substrate is not relevant at the harvest point.
Mineral Fertilizers
Generally, mineral fertilizers show higher nutrient uptake and agronomic use efficiencies compared to organic treatments
Organic Fertilizers
The significantly lower plant and inflorescence dry matter, leaf area and finally CBD yield of organic treatments are supported by the general lower nitrogen uptake efficiency (especially in the last two weeks which is the major sink stage) compared to mineral treatments.
If Using Organic Fertilizers Consider...
Organic fertilizer should be applied earlier at a higher rate to be available during the final two weeks of flowering when the sink demand for inflorescences is very high.
Best of Both
The higher availability of mineral fertilizer can be important for plant initial growth, while organic fertilizers can be employed as a more sustainable nutrient complementation during flowering without major yield losses.
Fertilizer Concentration: Take Home Message
The fertilizer concentration 160 produced 95% of the CBD yield of 240, while receiving one-third less nutrients.
Organic Fertilizer Usage: Take Home Message
If using organic fertilizers you may have to add more than someone else using mineral based fertilizers because of the lower nutrient uptake efficiency.
Nutrient acquisition was lower for the organic fertilizer during the final two weeks before harvest, resulting in reduced biomass and CBD yield compared to mineral fertilizer treatments.
Phosphorus Fertilization: Take Home Message
The fertilizer rate of P can be in general reduced during end of flowering to avoid unproductive nutrient accumulation in vegetative plant organs.
Link to Lecture Slides: drive.google.com/file/d/1sVH1JsMbtAGr1zq6egKyGUYxzooJWcL8/view?usp=drive_link
*Due to the description character limit the full work cited for "Impact of Organic and Mineral Based Fertilizers on Cannabis Yield" can be viewed at... docs.google.com/document/d/1xA-5AiNzeR8QHwvruKjZOT5nPD1FohgU/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true




![Agouti Mouse Model To Study Early Nutritional Effects on Epigenetic Gene Regulation
Agouti Mouse Model To Study Early Nutritional Effects on Epigenetic Gene Regulation
Professor DeBacco
YouTube Video
Low Dose Rad 2018. (2019, November 14). The Agouti Mouse Study 1080 [Video]. YouTube. https://www.youtube.com/watch?v=VM37fh5ykbg
What is Epigenetics
Epigenetic- literally means “in addition to changes in genetic sequence”
The term has evolved to include any process that alters gene activity without changing the DNA sequence, and leads to modifications that can be transmitted to daughter cells.
There likely will continue to be debate over exactly what the term means and what it covers.
Perhaps the best known epigenetic process, in part because it has been easiest to study with existing technology, is DNA methylation. This is the addition or removal of a methyl group (CH3), predominantly where cytosine bases occur consecutively.
DNA methylation was first confirmed to occur in human cancer in 1983, and has since been observed in many other illnesses and health conditions.
Second World War (Winter of 1944-45)
German blockade caused famine in the Western provinces of the Netherlands
A legacy longitudinal study 5 decades later showed that people born to mothers who were in the first three months of pregnancy during the famine had significantly higher incidences of obesity, diabetes, cardiovascular disease and cancer in their adult lives.
Fetal Susceptibility Hypothesis
Traditional Genetics could not explain this
However, in 2003 a study conducted by Robert A. Waterland and Randy L. Jirtle with mice may provide some supporting data…
Transposable Elements: Targets for Early Nutritional Effects on Epigenetic Gene Regulation
Waterland, R. A., & Jirtle, R. L. (2003). Transposable elements: targets for early nutritional effects on epigenetic gene regulation. Molecular and cellular biology.
https://www.tandfonline.com/doi/abs/10.1128/mcb.23.15.5293-5300.2003
Agouti Mice
Large yellow agouti mice
Demonstrated fetal susceptibility and opened up a new way to look at genetics
Genetic mutations were thought to be the cause of diseases, and while this may be the reason in some cases it is not the only cause.
Gene Regulation
Methylation- CH3, can block or turn off (silence) a gene
Each cell contains all of your DNA (few exceptions Ex. red blood cells), but look very different think of your skin cells vs your liver cells.
This is due to gene expression
Eye cells contain the genetics to produce hydrochloric acid, however good thing this gene is not expressed in your eyes, but is activated in your stomach.
Nature vs Nurture
Early in development signals are given to differentiate cells and these signals are carried on as the organism grows and develops.
The genetic signaling can be influenced by environmental factors (Ex. Stress, diet)
Environmental Epigenetics
At critical stages of development the environmental factors can have a greater influence on the final gene expression.
Shortly after fertilization is a critical time point as this is when the cells are first developing.
Famine in mothers while early in pregnancy impacting their developing fetus.
Agouti Gene
All mammals have an agouti gene that controls distribution of dark pigment.
Genetically identical mice
Some brown and stay a normal weight their entire life
Some tan/yellow and are obese and have high incidence of diabetes and cancer.
Differences due to changes in gene expression
Change is the result of a Transposon- viral segment of DNA that moves (jumps) to different positions in a cells genome.
This can alter gene expression
Tan/Yellow Mice- Transposon physically located next to the Agouti gene resulting in the over production resulting in the tan/yellow coloration AND also blocked the feeding control center in the brain
This resulted in them being obese, but this is also inheritable
Impact of Mothers Diet
The incorporation of methyl groups in the fed essentially silenced (turned off) the transposon
Results in the return to the normal agouti gene with mice being brown and normal weight.
Unmethylated early in development results in the activation of the agouti gene through the animals entire cells continuously throughout its life resulting in the animal always being yellow.
T
Environments Impact on Genes
Environmental factors can reprogram genetic inheritance
For better or worse
Counter Point
During reproduction, mammalian cells go through two full cycles of demethylation.
That process strips all methyl groups, and thus epigenetic information, from germ and embryonic cells.
To date, there is no evidence that epigenetic information can survive two rounds of this biochemical cleansing.
Link to Lecture Slides:
*Due to the description character limit the full work cited for Agouti Mouse Model To Study Early Nutritional Effects on Epigenetic Gene Regulation can be viewed at... https://docs.google.com/document/d/1vtEaBFiWfJcege_bn3Rg_1UZB4zbjgCS/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true Agouti Mouse Model To Study Early Nutritional Effects on Epigenetic Gene Regulation](https://i.ytimg.com/vi/sfbCZvLYp60/mqdefault.jpg)





