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Compendium: Earth-Water-Light-Microorganisms-Ion-Exchange-Nutrients

[Maschinenhaus]

Active member
Chapter 8

Indoor cannabis cultivation - Many problems?


Many problems can be prevented in advance, good gardeners know it, less is more!

Interactions between nutrients - causes of malnutrition. Causes of nutrient deficiencies are inharmonious nutrient ratios in the soil, in addition to insufficient supply due to soil depletion, nutrient leaching, pH-related establishment and oxygen deficiency.

Thus, a mutual influence of plant nutrients can occur due to uncontrolled fertilization measures, i.e. nutrients promote each other (synergism) or inhibit each other (antagonism) in the uptake.

Good, properly matured and stored compost actually contains everything we need to cultivate cannabis. We can forget about the marketing from the cannabis industry.

Useless products like bottled phosphorus, we can forget, bottled Ca-Mg, we can forget, the list would be long.

I water my plants with pure water from a reverse osmosis system, what the plant needs, it finds in the soil. I make sure that the soil is permeable to air and not too compressed. The soil must be able to breathe, water that seeps slowly brings oxygen and carbon dioxide into the soil.

My recycled Soil, after a year of rest and maturation in the cellar.

Recycled Organic Soil.jpg


As photosynthesis increases, the plant utilizes more nutrients, growth increases with supply. m the range of optimum temperature in conjunction with high illumination, the amount of nutrients should be increased;
low soil temperature lowers nutrient uptake → supply must be reduced!

High salt content increases the salt concentration in soil and substrate, in extreme cases salt damage can occur;
special attention must be paid to sodium and chloride content;
existing nutrients may have to be counted towards fertilization; soft water (< 8° dH carbonate hardness) lowers the pH, hard water increases it, possible consequences are determination or undesired release of nutrients.

The nutrients whose study is of greatest importance are nitrogen (N) and potassium (K). They are taken up by the plant in the greatest quantity and their optimum range in the plant (especially nitrogen) is relatively narrow, so that deficiency or excess nutrition is visibly apparent even with small deviations from the optimum.

Nitrogen nutrition is influenced by the humus content of the soil or substrate in addition to fertilization. Humic mineral soils and substrates supplied with organic fertilizers or containing compost are biologically highly active. Mineralization of organic matter initially releases plant-available mineral nitrogen as ammonium, which is converted to nitrate within a few days. Prerequisites are a slightly acidic pH and normal oxygen supply.
The conversion rate increases with increasing heat supply, so that excessive levels can occur in the summer months. Nitrogen fertilization should then be interrupted. In non-active or low-active substrates (white peat / clay mixture), these difficulties do not occur to the same extent.

In contrast, the effect of phosphate is less critical, since the optimum range is very wide and excess symptoms do not occur in practice. Often greenhouse soils are oversupplied with phosphate, so that fertilization can be dispensed with even for several years. The high contents are based on the behavior of phosphate in the soil. Depending on the pH value, insoluble salts are formed over a longer period of time, namely iron and aluminum phosphate in the acidic range, calcium phosphate in the weakly acidic to alkaline range. All compounds accumulate in the soil and are not washed out. Besides iron, other trace nutrients such as zinc, boron, copper and manganese are affected by the fixation in the acidic range.

Nutritional disorders frequently detected by soil analysis concern the potassium/magnesium ratio. A balanced equilibrium exists in mineral soils at a ratio of 2 to 3 : 1. Because of the intensive rooting of pots, nutrient ratios are less important, but observance prevents serious fertilization errors. Higher magnesium contents inhibit potassium uptake, high potassium contents inhibit magnesium uptake.

It should also be noted that a wide nitrogen/potassium ratio caused by excess nitrogen will result in relative potassium deficiency. Although the potassium content in the plant is at its optimum, it falls into relative deficiency due to excessive nitrogen fertilization. If, according to a soil analysis, the nutrient ratios are balanced, they will only remain harmonious if fertilizer is applied according to the nitrogen/potassium ratio specific to the plant.

Calcium and magnesium deficits and blockages

The discussions and confusion in grower circles speak for themselves on this topic.

In good soil mixtures with compost there can be no shortage!

There are blockages, imbalance of nutrient ratios, pH value, etc., I have repeatedly pointed out in previous chapters.

Leave the bottles of miracle products on the shelves, who bought a good mixture of primary rock flour, has no problems for years if he recycles this soil again and again.

In purchased soil, even special cannabis soil, a handful of primary rock flour is enough to exclude deficiency. It is anyway the lack of magnesium that is often the cause besides blocking (see above).

Once again as a repeat!

Depending on the condition of the soil, the trace elements are susceptible to precipitation. This means that they can no longer be absorbed by the roots. In fertilizers they are therefore often processed as chelates (organo-metal complex). This protects them from blockage in the soil.

The balance between anions and cations

Under normal conditions, plants prefer to take up cations, i.e. positively charged ions, rather than the anions nitrate, phosphorus and sulfur, which are more important for nutrition.

As a result, the plant's internal charge ratios become imbalanced. To compensate, it releases hydrogen H + through the roots to the soil or substrate. This lowers the local pH value in the soil. In addition, the cations potassium K + , magnesium Mg ++ , calcium Ca ++ and ammonium NH 4 + bound to clay particles dissolve and are thus available again for the plants.

Reference

Hortipendium (German Language)

Hauert (German Language)
 
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[Maschinenhaus]

Active member
Chapter 9

Light spectrum and photosynthesis


Nature shows us how the hardly inexhaustible power of the sun can be tapped. Its light is transformed into chemical reaction energy and stored.

Pigments absorb light for photosynthesis. In photosynthesis, energy from the sun is converted into chemical energy by photosynthetic organisms. However, the different wavelengths in sunlight are not all used equally in photosynthesis. Instead, photosynthetic organisms contain light-absorbing molecules called pigments that absorb only specific wavelengths of visible light while reflecting others.

The range of wavelengths that a pigment absorbs is its absorption spectrum. In the figure you can see the absorption spectra of three important pigments in photosynthesis: Chlorophyll a, Chlorophyll b, and β-carotene. The wavelengths that a pigment does not absorb are reflected. The reflected light is what we see as color. For example, plants appear green to us because they contain a lot of chlorophyll a and b molecules, which reflect green light.

Most photosynthetic organisms have a variety of different pigments, allowing them to absorb energy from a wide range of wavelengths. Below we look at two groups of pigments that are important to plants: Chlorophylls and Carotenoids.

Chlorophylls


There are five main types of chlorophylls: Chlorophylls a, b, c, and d, and a related molecule, bacteriochlorophyll, which is found in prokaryotes. In plants, chlorophyll a and chlorophyll b are the major photosynthetic pigments. Chlorophyll molecules absorb blue and red wavelengths, as shown by the peaks in the absorption spectrum above.

Chlorophyll molecules consist of a hydrophobic ("water-fearing") tail that protrudes into the thylakoid membrane and a head consisting of a porphyrin ring (a circular group of atoms surrounding a magnesium ion) that absorbs light.

Pigments_absorption spectra.png

This is the spectrum in midsummer around noon with a cloudless sky as it reaches the plants.

lichtspektrum-mittags-me.jpg


This is the spectrum in the morning and evening.

lichtspektrum-morgens.jpg


Photosynthetically active radiation (PAR or PhAR) is defined as the electromagnetic radiation in the range of the light spectrum that phototrophic organisms mainly use in photosynthesis. It largely coincides with the range of radiation visible to humans with a wavelength between 380 nm and 780 nm. About 50 percent of global radiation lies in this range.

The photosynthetic efficiency is an efficiency and depends on the wavelength of light and the absorption behavior of photosynthetically active substances. Its spectral distribution is of interest, such representations and effects are called action spectrum (of photosynthesis), effect spectrum (of photosynthesis) or effect spectrum of photosynthesis.

McCree -Curve

Today we know that the range considered at that time was not sufficient, photosynthesis does not start at 400nm and ends at 700nm, no it goes much further and on cannabis certain ranges have a particularly strong effect.

Here again the repetition of an old measurement from the year 2017. In the year 2022 it looks again differently. Electrical efficiency, i.e. saving electricity, and efficiency of photosynthesis through light spectra and light quantities are two different things.

Nichia Horticulture Array - 2017
400nm - 700nm = 319,025 μmol/s
380nm - 780nm = 335,920 μmol/s
DLI of Array = 5,576 mol/m2/day

The-McCree-curve-overlaid-with-PAR-and-Lumens-as-represented-by-their-comparative.png


PAR means Photosynthetically Available Radiation

PUR means Photosynthetically usable radiation

PSR means Photosynthetically stored radiation

Emerson effect

The Emerson effect or enhancement effect is the name given to a particular phenomenon in the study of photosynthesis. Simultaneous irradiation with light of two wavelengths causes a higher photosynthesis rate than the sum of irradiations with only one of the two wavelengths. The effect is named after its discoverer Robert Emerson.

Exposure of unicellular algae or isolated chloroplasts to monochromatic light of either 680 nm or 700 nm wavelength gives very specific rates of photosynthesis (O2 production). When irradiated with both wavelengths simultaneously, one obtains a significantly higher photosynthetic rate than by the sum of the individual exposures.

This seemingly paradoxical result can be explained if one assumes the existence of two photosystems, each with a wavelength-specific reaction center P700 and P680, respectively. The maximum photosynthetic rate can only be achieved if both systems are utilized to capacity. If only 700 or 680 nm is irradiated, there is a congestion in the electron transport chain and no photosystem can work optimally.

"The Green Revolution"

bdw author Reinhard Breuer on how scientists are trying to "pimp" photosynthesis - they want to further optimize the efficiency of the natural concept. Because there is obviously potential for this. The author first explains why certain factors reduce the yield of plant photosynthesis. Researchers are already successfully working on methods to eliminate these limitations, Breuer reports. They are not only intervening in the mechanisms of photosynthesis in plants. Some scientists are also trying to produce organic substances using light energy through largely artificial systems.

UV radiation

Ultraviolet radiation is shorter wavelength than blue or violet. Sometimes it is erroneously called "UV light", which is not quite correct, because UV radiation is not visible to humans (but it is visible to a number of animals (bees, bats, etc.). Since UV radiation is more energetic, it is harmful to humans. UV light penetrates into the skin layers and can trigger chemical processes there.

This ranges from rapid aging of the skin (mainly due to the death of coller genes) to changes in the genetic material (UVB radiation). Therefore, especially in summer, care should be taken to protect the skin well with sunscreen or to avoid direct sunlight.

Infrared radiation

Since plants are mostly made of water, infrared radiation warms them up quickly. Water is very good at absorbing infrared radiation. Protection from infrared radiation in the greenhouse therefore has a great influence on plant temperature.

Any radiation with a wavelength of 700 nanometers (nm) or more is called infrared radiation. Above red light, therefore, the infrared range begins. In the spectrum from 700 to 2500 nm lies the near-infrared range (NIR), also called short-wave infrared radiation. Above this range, the long-wave infrared radiation begins. Since the plant does not need the infrared light for photosynthesis, it is no problem to filter out this light. This prevents excessive heating of the plant. This heating is a result of the properties of water.

Blue, green, red and short-wave near-infrared light pass through water, but infrared light from the farther spectrum, especially above 1200 nm, heats it. On a sunny day, the plants, which are after all mostly water, can heat up considerably. Then the plants and the greenhouse elements, which have also absorbed radiation, heat the air in the greenhouse. So, on such a day, the plants heat up more than the air in the greenhouse. The plant temperature will generally be higher than the temperature in the greenhouse.

Up to a certain limit, the heating of the plant is naturally positive. After all, the heat promotes various processes in the plant. But this is true only up to a certain limit. The combination of a lot of light, a high plant temperature and low humidity first leads to the cessation of photosynthesis and then to real damage.

But even before this stage is reached, it can be very useful to limit the plant temperature somewhat. The evaporation process of the plants then slows down, which means that the ventilation windows need to be opened less. This leaves more CO2 in the greenhouse, which promotes growth.

Cyan gap

1-s2.0-S0925838820318338-fx1_lrg.jpg


LED Basic and CRI

Developing white light-emitting diode (LED) based solid-state lighting has been a major trend in the context of global response to energy conservation, electricity consumption reduction, and environment protection. The mainstream white LEDs are based on the combination of Y3Al5O12:Ce3+ (YAG:Ce3+) yellow phosphors and InGaN blue LED chip, whose significant advantages such as high efficiency, low energy consumption, high brightness, long operation time, and eco-friendliness are incomparable to those of traditional lighting sources.

But unfortunately, the deficiency of the red spectral region leads to the high correlated color temperature (CCT; > 4500 K) and poor color rendering index (CRI; Ra < 75) of the resulting cold white light. The CRI as a dimensionless index reflects and quantifies how true a given light source renders the color of the objects.

So it can serve as a key parameter to evaluate the quality of the white light. CRI is shown in numbers ranging 0 to 100 while the color rendering ability of daylight is defined as 100, or in other word, a light source with broader spectral composition is more likely to provide high CRI. The higher the CRI is, the better the color rendering ability is. Generally, white light with Ra > 80 can make object look natural and make human eyes feel comfortable, which is desirable in indoor lighting.

However, the conventional NUV-pumped white LEDs also suffer from the poor color uniformity because there is a lack of the cyan region ranging from 480 to 520 nm in their emission spectra (so-called cyan gap between the blue and green emissions). This spectrum cavity prevents the realization of the real “full-visible-spectrum lighting” and thus makes it difficult to achieve high-CRI white LEDs.

Therefore, as long as the cyan gap is filled, the full-visible-spectrum lighting with high CRI values can be realized in white LEDs based on “trichromatic phosphors + NUV LED chip” combination. In view of this, it is very interesting and meaningful to exploit efficient NUV-excited broad-band green phosphors with unique advantage that their emission spectra can cover the cyan region of 480–520 nm.

Reference

Wikipedia

Lichtmikroskop (German Language)

Redusystems

Bionity

Sciencedirect

khanacademy.org (German Language)
 
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[Maschinenhaus]

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Chapter 10

Fertilizer and additives

Silica


Field horsetail (Equisetum arvense), comfrey (Symphytum officinalis) or stinging nettle (Urtica dioica) are among the plants that are very rich in silicic acid.

Silica helps plants better absorb important nutrients. It not only helps plants thrive in healthy soil, but also in a growing medium that is extremely low in minerals.

Silica can increase a plant's metabolism, allowing it to more quickly form the cells it needs to thrive. For example, silica-rich plants have higher chlorophyll production compared to others, which allows them to photosynthesize at a higher rate, producing more energy, which stimulates growth.

In terms of nutrient uptake, silica proves doubly beneficial. Giving silica to plants growing in healthy soil helps optimize nutrient uptake and ensure that both essential and non-essential nutrients are present in the best concentrations. But that's not all. Adding silica to low-quality, nutrient-poor soil can increase the capacity of cannabis roots to extract each nutrient molecule from it.

One of the main reasons cannabis plants use silica is for the production of cell walls. By creating stronger cell walls, the plants themselves naturally become more robust because they develop thicker stems and branches. This happens in two ways.

First, they are simply stronger in the sense that they can withstand more weight and wind, which is especially beneficial for outdoor growing (although it has its uses indoors as well). If you're aiming for a monster crop, your plants need to be able to support the amount of flowers they produce. You certainly don't want to look in your grow box and discover that a cola has gotten too big and is breaking off. Silica can help prevent this from happening.

In addition, it can also help prevent osmotic stress. This is the stress caused by water flowing in and out of cells. In the first instance, you can counteract this with a good watering schedule; however, it is worth supporting the plant with additional silica.



Yeast and sugar

Each by itself contains many plant-promoting micronutrients. Combined, they are a dream team for fertilizing high-yielding plants such as tomatoes and other vegetables, as well as potted and houseplants. The yeast fertilizer is easy to make yourself.

Bakers' yeast and sugar are not direct fertilizers that stimulate plants to grow and bloom due to their so high content of minerals such as nitrogen or potassium, but they fertilize indirectly. That is, the organisms in the soil are so well nourished that they strengthen tomatoes and other vegetable plants through their increased activity:

Protein, minerals, trace elements and, last but not least, the yeast fungi in the yeast and carbohydrates in the sugar "feed" the soil organisms, which in turn tap into nutrients such as nitrogen in the soil, making them more available to tomatoes or their roots. The sugar also serves as food for the yeast fungi, other microorganisms and earthworms, which can thus develop their full power.

The yeast fertilizer is easy to make: For the very simple version without sugar, stir one cube of fresh yeast or one packet of dry yeast into ten liters of lukewarm water until the yeast has dissolved. Let the mixture rest for an hour, pour it into a watering can and water the tomatoes with it every two to three weeks, always stirring beforehand. For the second variant, add two tablespoons of sugar to the yeast solution.





Liquid Organic Fertilizer from Egg Shells



Eggshells consist of 90 to 95% calcium carbonate (CaCO3), which is also called "carbonic acid lime". Lime is suitable for raising or stabilizing the soil pH, but the effect of eggshells is quite slow. To dissolve the lime, carbonic acid (HCO3-) must be present in the soil, which is produced by the respiration of plant roots. With the help of carbonic acid, the compound Ca(HCO3-)2 is formed, which in turn breaks down into the calcium ion Ca2+ , carbon and water - during this process the pH value increases. Unfortunately, this is not the case with clay-rich soils, as they are too chemically stable to be affected by the slow-acting addition of lime.

Tip: Heavy soils are better treated with quicklime or slaked lime if the pH needs to be raised. For example, quicklime is contained in untreated wood ash. You can read more detailed information on using wood ash as a fertilizer in our special article. In any case, before applying lime, first test the pH of your soil.

The calcium ions (Ca2+)released in the reaction with carbonic acid are essential in cementing soil particles. They bond clay minerals to humus molecules, creating stable crumbs that promote plant growth in many ways. And, of course, the calcium released is a nutrient element essential for plants: it serves to stabilize the cell wall and as a signal ion involved, for example, in the opening of stomata.

In addition to calcium, the nutrients potassium, phosphorus and magnesium are also present in small quantities. Overall, the quantities of eggshells produced in the household are so small anyway that their use as fertilizer is only worthwhile in some cases, as you will learn in the following paragraph.

Summary: How do eggshells work as fertilizer?

- Eggshells consist mainly of calcium carbonate
- Calcium carbonate can raise the soil pH slowly
- The pH effect is limited to light, clay-poor soils
- Released calcium ions are valuable cements of soil particles and, together with humus and clay minerals, can improve soil structure
- Calcium is one of the essential nutrients for plants.

Since eggshells provide almost only calcium, fertilizing with them alone is not possible.



Banana peels contain many minerals

The dried peel of a ripe banana contains around twelve percent minerals. Potassium takes up the largest part of this, about ten percent. The remaining two percent are mainly magnesium and calcium. There are also smaller amounts of phosphorus, sodium and sulfur, and a small amount of nitrogen.

Because of its high potassium content, banana peel is particularly suitable for fertilizing flowering shrubs and roses. The plants are more flowering, healthier and come through the winter better with the help of the potassium. Since the nitrogen content in banana peels is very low, plants can be fertilized with them throughout the season without running the risk of overfertilizing them. About 100 grams of banana peel fertilizer per plant is a good dose.

Reference

Geo (German Language)

Plantura (German Language)
 
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[Maschinenhaus]

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Chapter 11

Homemade fertilizer tabs and recipes with organic stuff - Primary rock flour - Mykorrhiza

Prologue:


All my soil mixtures I recycle and let them rest for 1 year, so over time a better and better soil for cannabis but also other plants.

The root balls I leave in the pots, I give before the resting phase in water dissolved yeast and sugar, as well as gel from my aloe vera. 2x in the time I give some warm aquarium water with mulm on the soil. After a total of one year of rest and maturation phase in the cellar I sieve out the lava granules and pumice.

What is not yet completely decomposed biomaterial goes on the compost. Into the sifted soil then comes 10% to 25% fresh compost, worm humus and one, two tablespoons of bat guano and an espresso cup full of primary rock flour. I then rebuild the pots with a drainage of coarse lava granules (20mm and up) and finer lava granules up to 10mm with pumice goes into the soil, it's good for soil respiration and the microorganisms and roots love it.

My mother keeps taking this recycled soil away from me for her raised beds and herb garden, she wants to keep me from growing "drugs" this way, at least she thinks so.

That's why I bought a large wheeled garbage can in my city apartment in the basement, like the one used by garbage collectors here in Germany. There I recycle the earth bales as described above.

Guanokalong powder contains:

N = 1%
P = 10%
K = 1%

Fulvital Plus WSP contains:

Fe = 4%
Zn = 2.5%
Mn = 2.5%
Cu = 1.0%
Mg = 3.5%
S = 6%

Primary rock flour diabase contains:

SiO2 = 40-50%
Al2O3 = 10-12%
Fe2O3 = 9-12%
CaO = 9-12%
MgO = 4-6%
Na2O = 2-5%
K2O = up to 1%

Primary rock flour zeolite contains:

P2o5 = 0.41%
K2O = 2.9%
MgO = 2,9%
CaO = 4,08%
Ni = 62,2mg/kg
SiO2 = 40-45%
Al2O3 = 11-15%
CaO = 10-15%
Mg = 6-8%
K = 3-4%

Primary rock flour natural bentonite contains:

SiO2 = 59.5%
MgO = 2.0%
Fe2O3 = 4%
K2O = 0,5%
Al2O3 = 17%
Na2O = 0,4%
CaO = 4%

Banana peels

The peel of the banana also contains nutrients such as phosphate, potassium or magnesium. You can make the plant fertilizer yourself by cutting the peel into small pieces and working them directly into the soil, for example together with coffee grounds or loose tea. But it can also be processed in its dried state. Crushed in a blender, simply fold it in.

For plants, the rule of thumb is 100 g of banana peel per plant. This way you avoid overfertilization.

Onion peels

Onion peels contain potassium, magnesium and calcium. Simply mix 100 g of onion peels with a liter of water and leave the mixture for a week. The container should be well closed and placed in a sunny place.

You can also combine the peels with leaves and straw. So you contain a high-quality fertilizer, which contains all the nutrients for plants.

Do it your self Alternative to expensive BioTabs

Oat bran, dry yeast, potato starch, organic cane sugar, liquid EM microorganisms and BioTrissol.

Bowl, disposable gloves and then everything is mixed by hand until you can form balls, flattened also works, but then they crumble more. Let the balls dry, cost for 100 pieces about 10€.

The principle is like BioTabs, there is recommended to incorporate a handful of oats or rice in the soil, oat bran is much better suited. Effect: Already in young plants a turbo turnaround in sugar and starch!

The mineral elements, macro and micro minerals - primary and secondary also benefit from this and are also abundant in good soil.

A purchased, organic light-mix soil is completely sufficient, I use an organic growing soil for herbs without perlite for a new approach. Yeast as a spray is suitable to protect tomatoes from rot, powdery mildew or gray mold. The yeast enters into symbiosis with the plant, forming a barrier that other fungi can not penetrate.

Use yeast as fertilizer

However, baker's yeast can also do a good job on the compost pile. The yeast fungi accelerate the compost formation enormously. Even if remnants of the yeast fertilizer solution remain, simply pour them into the compost.

Most important ingredients of baker's yeast:

- Vitamin B1, B2, B6
- Niacin
- Folic acid
- Biotin
- Iron
- magnesium
- Zinc
- Potassium
- Protein

Production of fermented yeast fertilizer

Material:

- 100g baker's yeast
- 200ml organic brown sugar
- 10 liters of warm water

Crumble the baker's yeast and mix it with sugar. Put the mixture in a bucket and slowly fill it with the water. Let the mixture ferment for a week. After a week, your yeast fertilizer is ready to use. Use the resulting concentrate in a ratio of 1:10 to water your plants.

Production of non-fermented yeast fertilizer.

Material:

- 1 cube of baker's yeast
- 10 liters of water

First, crumble the baker's yeast and mix it with a little water to make a uniform mass. Fill up the mixture with the remaining water. The water should be lukewarm. Let the mixture rest for an hour. Right after that you can water your plants with it.

Natural fertilizer properties

Coffee grounds
- Contains 2% nitrogen, 0.4% phosphorus and 0.8% potassium
- Plenty of nutrient-poor structural material makes it the perfect starting material for humus formation

Horn meal and horn shavings - Rich in nitrogen, phosphorus and calcium
- Natural long-term effect
- Potassium must be additionally fertilized

Ash - Only ash from burning untreated wood, straw, other plant materials and non-glossy printed paper can be used for fertilization
- Contains high levels of phosphorus, potassium, calcium, magnesium and trace nutrients
- Very high pH value (10 to 13)
- Quickly effective

Eggshells - Consist almost entirely of calcium carbonate (carbonic acid lime)
- High pH value
- Slow acting

Horse manure - Composed of urine, feces, and bedding from the horse barn
- Contains nitrogen, phosphorus and potassium, as well as trace nutrients
- Structural material can stimulate humus reproduction
- Fresh horse manure is a plant fertilizer, composted horse manure is a soil conditioner and long-term fertilizer

Urine of mammals - Rich in nitrogen, phosphorus, potassium, calcium.
- Not germ-free, which limits its use
- May contain substances ingested through food by the respective producer

Guano - The extraction of guano harms the environment at the extraction site
- Mining is sometimes carried out under inhumane conditions

Reference



Gartenmoni

Sources:


 
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[Maschinenhaus]

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Chapter 12

Light spectra of CMH and LED and their influence on flowering duration and trichome maturity.


There are numerous studies dealing with the influence of radiation of certain wavelengths on the growth of different plant species. However, the results obtained are not always consistent. Thus, exposure to identical wavelengths may well lead to different growth results in different plant species.

UV light accounts for about 10% of the sun's total light output and is divided into several subtypes. The three subtypes focused on in this article are UV-A (315 - 400nm), UV-B (280 - 315nm), and UV-C (100 - 280nm). UV radiation affects many aspects of plant growth, including development of defense compounds and structures, prevention of insect and fungal attack, and DNA damage.

Since plants are photosensitive creatures, it stands to reason that they can be affected not only by the visible portion of electromagnetic radiation (light), but also by the invisible portions of sunlight.

It is becoming increasingly clear that it is not simply parts of the solar radiation that are to be judged as useless or even harmful. Rather, it seems that the quantity makes the poison?

The light and dark reactions of photosynthesis are interdependent. Since the dark reaction requires ATP and NADPH/H+ from the light reaction, it can only really take place in the dark if ATP and NADPH/H+ are artificially supplied to it. Conversely, the light reaction can only proceed poorly or not at all if the dark reaction is inhibited, e.g. by CO2 deficiency, and precursors such as ADP and NADP+, which are normally supplied from the dark reaction, are missing.

The Curious Effects of UVA and UVB

Cryptochromes, phototropins, and slow-transient light (ZTL) are the three primary photoreceptors that mediate the effects of UVA. UVB light is primarily mediated by the UV-R8 monomer.

Since THC is produced and stored in hemp trichomes, UV light also increases the active ingredient content. Now, UV radiation can also be harmful to plant tissues, but modern research shows that there are also several distinctly positive responses to UV radiation.

The various developmental or physiological changes are induced by a plant's photoreceptors, which detect specific wavelengths of light. Photoreceptors are also sensitive to light quantity, quality and duration.

Independent research has shown that even UVA light alone can increase active ingredient levels, such as THC and CBD production in hemp plants. The combination of UV-A and UV-B light (from a standard "reptile lamp") also increases THC and CBD production, but the inclusion of UV-B in the light has noticeable adverse effects on plant growth compared to UV-A only.

It is recommended to use only UVA light without UVB wavelengths.

The UV-A still increases the production of secondary metabolites such as THC, CBD, terpenes and flavonoids, but without the negative effects of UV-B light.

It all depends on the colors

How does light of different wavelengths affect plants? Plants use only certain light frequencies for photosynthesis. These frequencies are related to the absorption properties of various pigments that are incorporated in the cell organelles called chloroplasts. The different pigments influence various plant development steps. Most of these pigments absorb light in the wavelengths corresponding to the colors blue and red. This is why most leaves appear green, as these wavelengths are absorbed to a small extent. The most important pigments are chlorophyll A, chlorophyll B, and the carotenoids.

The wavelengths predominantly absorbed by these are called Photosynthetically Active Radiation (PAR) and span a range from 400 to 700 nm. In addition, there are the phytochromes, which are photoreceptors that control numerous processes in plants - for example, growth direction or flower opening - and absorb light of wavelengths 660 and 730 nm. Which wavelength controls what depends on the plant genus and can also vary from variety to variety.

The various plant photoreceptors can be regarded as switches that activate or deactivate metabolic processes and thus induce associated reactions. The different photoreceptors have specific absorption patterns and are thus addressed by light of certain spectral ranges. For example, the photoreceptor phytochrome responds to red or far-red light and controls elongation growth. Phototropin or chryptochrome are blue light receptors that can, for example, influence directional growth or the content of ingredients.

LEDs can be used to selectively stimulate photoreceptors because they emit light in very narrow wavelength ranges compared to conventional light sources, such as high-pressure sodium lamps. The challenge is to assemble light spectra from LEDs of different colors that are adapted to plant crops and/or crop sections, since different plant species and even varieties can react quite differently to the same light spectrum.

DR, FR and NIR have an influence on the active ingredient profile and the terpenes of cannabis, presumably they have a particularly strong effect on the terpene profile, science and I do not know exactly (yet).

The influence of soils or soil mixtures, hydro cultivation should also have a strong effect on the terpenes and the active ingredient profile?

Flowering and ripening duration of trichomes under Adjust A Wing Hellion CMH 630W

CMH has a very wide spectrum, red ranges like DR 660nm and NIR 730nm, with CMH the spectrum at NIR yes goes to well over 800nm.

Delay average:

Durban -11 days (comparison to CLU048 without UV/FR).
Oaxacan -17 days (compared to CLU048 without UV/FR)
Orange Bud -14 days (to breeder specification)
Durban Dragon -9 days (comparison to CLU048 without UV/FR)
Afghan Kush -9 days (to breeder specification)
Black Domina -15 days (compared to CLU048 without UV/FR)
Neville`s Haze -22 days (compared to CLU048 without UV/FR)

Good to know and Reference

How does UV light affect plants?







Influence of the different wavelengths on growth

The Ultimate Lighting Guide for Cannabis Cultivation
 
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[Maschinenhaus]

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Chapter 13

Photomorphogenesis


The name C3, C4 is derived from the first stable intermediates in the fixation of CO2 (from air to C metabolism). In C3 plants, 3-phosphoglycerate, which has 3 carbon atoms, is a C3 scaffold. In C4 plants, oxaloacetate, a C4 scaffold, is formed.

The reason for the formation of different intermediates is due to different enzymes that bind the CO2. In C3, this is RuBisCO, which can also bind oxygen and is therefore only effective at higher CO2 concentrations (concurrent reaction). C4 plants have PEP carboxylase, which is much better at binding CO2. Therefore, the plant can effectively absorb low concentrations of CO2.

In C4 plants, fixation is divided into two steps spatially separated in the leaf. In CAM plants into two temporally separated steps, as si take up CO2 at night and fix it during the day when they get light energy.

The biological purpose of different systems is to adapt to different climatic conditions:

C3 plants tend to grow in cool and temperate relatively humid zones where the stomata can be mostly open and the plant gets a lot of CO2 and takes up little of it (because oxygen competition for RuBisCO).

C4 plants exist in warm zones where they hardly open the stomata as a protection against desiccation. Therefore, they need PEP carboxylase to absorb the little CO2.

CAM plants are adapted to deserts, they absorb CO2 at night and fix it during the day with the energy of the sun.

CAM plants are cacti, pineapple and C4 plants are many grasses, corn, reed, millet, hemp could be a C4 plant?

For a deeper understanding

For the control of growth, the so-called photomorphogenesis, plants need special wavelengths that occur in the natural course of daylight. Mainly, length growth and flower formation are controlled by the interaction of red light (660nm) and dark red light (730nm).

When the sun is low, at sunset, the proportion of dark red light increases and changes the red/dark red ratio. This causes the plant to switch its photosynthesis to nighttime dormant mode. A similar thing happens when plants are shaded. In general, plants react to this with stronger length growth (shade escape), fewer side shoots and accelerated flowering.

This effect can be used to accelerate the nightly recovery of the plant by artificial twilight. Normally, a plant needs about 1-2 hours to switch its metabolism and hormone production to night mode. With a 730nm stimulation, a plant only needs 10-15 minutes. Thus, with artificial LED lighting, the day-night rhythm of plants can be optimized. The day can be artificially prolonged if the plant is quickly put into sleep mode afterwards. Faster flower formation is also achieved by this effect.

Professional LED lighting also shortens the time until flowering starts and likewise the necessary flowering duration, as the dark red light component also plays an important role in stimulating the flower formation of short and long day plants. Normal red light (660nm) stimulates flower formation in long-day plants and prevents it in short-day plants, such as pointsettias. Dark red light (730nm) has the exact opposite effect here.

If the available amount of light does not cover the needs of the plant, it tries to compensate for this deficiency by growing in height in order to get more light. Thus, the growth of the plant can be influenced by means of light quantity and wavelength. Depending on the demand, the plants grow higher or more compact and thus produce higher yields.

This article from the University of Hamburg is 20 years old

The majority of photomorphogenic processes of terrestrial plants are controlled by bright red light and an alternation between bright red (lambda = 660 nm) and dark red (lambda = 730 nm). The associated receptor is the phytochrome, a protein-chromophore complex that can exist in (at least) two state forms that can be reversibly changed from one to the other by exposure to light.

Phytochrome is a chromoprotein whose state is affected by light. It is formed predominantly in darkness and is initially present as PR (P is the abbreviation for phytochrome, R stands for red). After irradiation with lambda= 660 nm light (light red, red) it changes into PFR [FR=far red; in German one could also write: PHR (light red), resp. PDR (dark red); or using the wavelengths P660, resp P730]. PFR is converted back into PR by lambda = 730 nm light (dark red). PR is the biologically inactive form, PFR is the biologically active form.

PR is formed in the cytoplasm in darkness and accumulates there until a certain level is reached. An equilibrium between synthesis and (slow) degradation is established. Conversion to PFR after irradiation with bright red light is a rapid process. PFR is extraordinarily unstable, so the phytochrome level in the cell drops after exposure to one to three percent of the original value, which presumably represents a new equilibrium between PR synthesis and PFR degradation. After darkening, the phytochrome level increases again due to a de novo synthesis of PR.

With the onset of a light period, physiological activity begins, and the photophilic phase begins. After about 9-12 hours, any further light supply has an inhibitory effect on plant development. The plant enters its scotophilic (dark-loving) phase. ... it says that the supply of PFR is exhausted at the end of a photophilic phase due to forced degradation and lack of replenishment, so that the plant can no longer perceive light at all.

Hemp has an insane growth rate and thus also an extremely high photosynthesis rate at high light flux. For me, this is THE argument for a C4 metabolism. A C3 plant simply does not achieve this efficiency.

The required amount of water is not suitable as a reliable indication, because hemp shows on the one hand quite adaptations to temperate climate, which is reflected in the anatomy (therefore, the classification is probably difficult on the basis of anatomical features), on the other hand, it is in the closet-growed strain to grows that require more water than their colleagues in the dry highlands.

Furthermore, it is quite possible that C4 plants also have high water requirements, because the C4 pathway is well suited both to use CO2 well in smaller concentrations (dry highlands) but also to use the much light in very strong sunlight to bind a lot of CO2 and thus gain a growth advantage. The latter applies to tropical climates, although here, of course, there is rarely a lack of water.

So C4 metabolism makes sense for indica and sativa.

So: C4 is also an adaptation high light density to use, so it is much light at once better used. In temperate zones the sun shines longer, but the lumens per m² are less.

Photosynthetic photon flux density, PPFD (Photosynthetic Photon Flux Density) in µmol/m²/s

This value is used to measure the number of growth-relevant photons that actually reach the plant. These micromoles are extrapolated to the square meter per second. The distance of the luminaire to the plant must also be specified here. This unit is comparable to the specification of the illuminance in lux in the area of white light.

To consider the photon flux density alone would be wrong, because the angle of radiation or the scattering of the light and thus the distribution of the photons over a certain area also plays a decisive role. For uniform and large-area scattering of light, interconnected horticulture LED lighting systems in strip form are commonly used. Square lighting systems, on the other hand, tend to achieve a greater depth effect, making them more suitable for tall-growing plants and smaller areas. Information on photon flux density and light scattering is usually provided by the PPFD plots included in the data sheet.

Even if the PPFD parameter says nothing about the actual light spectrum and the associated grow application, it still provides an additional point to objectively evaluate and compare different light sources. The disadvantage, however, is that not all manufacturers disclose their PPF values and these can hardly be measured.

Plants cannot absorb an unlimited amount of light. Every plant has a light saturation point (LSP). Above this point, a plant's photosynthetic output can no longer be increased by increasing the light intensity. If the light intensity is increased beyond the LSP, the photosynthetic apparatus can be damaged, thus reducing the photosynthetic output or causing the plant to die.

Basically, plants can be divided into 3 categories: Shade plants (low LSP), Sun plants (high LSP) and C4 plants (very high LSP).

Reference

Many thanks especially to Mak!

Oregon State University

Light aspects for the perfect plant growth (German Language)
 

[Maschinenhaus]

Active member
Special - magnesium and calcium

The literature says that a ratio of calcium to magnesium of 3:1 is perfect. In my opinion, problems are not caused by calcium but rather by magnesium, often due to impaired nutrient absorption - a blockage.

Let's focus on magnesium!

Magnesium is an essential nutrient for all plants, because without magnesium no photosynthesis is possible. If there is a magnesium deficiency, the plant's roots will not function adequately, which can cause problems with the uptake of other plant nutrients.

Therefore, you should ensure the magnesium content regularly by fertilizing the plant. Even as a preventive measure, such a special fertilizer can be useful. However, at the latest when deficiency symptoms appear, a universal fertilizer is no longer sufficient. However, it is best to mix his soil optimally and to exclude that you get a problem with calcium / magnesium, take a good primary rock flour.

But beware, not every of the offered primary rock flour is also good, it depends on the composition!

Signs of magnesium deficiency


As the primary "building block" of chlorophyll, magnesium is what gives chlorophyll - and the plant itself - a healthy, bright green color. The first and most easily recognizable sign of magnesium deficiency in cannabis plants is that the leaves turn worryingly from green to pale green to yellow.

Magnesium is not only essential for photosynthesis, it is also needed for the absorption of other vital nutrients. These include in particular nitrogen and phosphorus, two of the three main nutrients. Plants lacking magnesium not only cannot photosynthesize, but also cannot develop sufficiently large and healthy roots and flowers.

In fact, cannabis plants with magnesium deficiency do not even make it to flowering stage. When the supply of magnesium is exhausted, more and more leaves turn yellow, then brown, and finally they fall off completely, which ultimately causes the plant to die.

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If you want to check your plant for a magnesium deficiency, it's best to look for discoloration. However, not every color change indicates a magnesium deficiency. For example, brown coloration shows up when there is a water deficiency, whereas rusty brown spots can also occur when there is a nutrient deficiency.

The surest signs of magnesium deficiency are chlorosis: chlorosis is a result of nutrient deficiency in the plant. This results in a breakdown or reduced formation of chlorophyll, the so-called "leaf green", and the leaves turn yellow or reddish. The yellowing begins in the middle of the leaf, while the leaf veins and the edge of the leaf remain green the longest.

Caution: Chlorosis also occurs with iron deficiency. However, while in the case of iron deficiency these form first on young leaves, in the case of magnesium deficiency the older leaves turn yellow first.

As a first measure for nutrient blockage, I give a carbonated mineral water (because of the ph) that has a good calcium to magnesium ratio and is low in sodium.

As an example, a mineral water available in Germany, which is suitable for infant feeding, with a ratio mg/l of:

- Calcium 96.9
- Magnesium 28,3

The ph value of the mineral water and the dissolved minerals break a blockage in the absorption, the carbonic acid loosens the soil mixture as it seeps into the pot. Too strongly compacted soil mixtures can also be causes of nutrient blockages!

Tap water, you should know and know how it is composed according to the supplier. Often tap water is treated with chlorine, has high nitrate levels, etc., so I use a reverse osmosis system. You can mix your tap water with it or take pure osmosis water.

Smartline-Basic_Produktbild_zu_5b0826a847461.png


Reference

Royalbrinkman

Osmofresh

Sensi Seeds

Garden of Green
 

Mitsuharu

White Window
Veteran
Let's focus on magnesium!

Magnesium is an essential nutrient for all plants, because without magnesium no photosynthesis is possible. If there is a magnesium deficiency, the plant's roots will not function adequately, which can cause problems with the uptake of other plant nutrients.
I really never had any problems like that, even now as i'm growing with LED... I always read calmag here, calmag there but it seems my plants are fine without it or i'm just using the right soil. I told you in our german forum that i'm using tomatoe soil and i'm doing good with it for years... I always wonder why anybody thinks that they need to buy all this cannabis grow industry stuff!?
 

flylowgethigh

Non-growing Lurker
ICMag Donor
Chapter 8

Indoor cannabis cultivation - Many problems?


Many problems can be prevented in advance, good gardeners know it, less is more!

Interactions between nutrients - causes of malnutrition. Causes of nutrient deficiencies are inharmonious nutrient ratios in the soil, in addition to insufficient supply due to soil depletion, nutrient leaching, pH-related establishment and oxygen deficiency.

Thus, a mutual influence of plant nutrients can occur due to uncontrolled fertilization measures, i.e. nutrients promote each other (synergism) or inhibit each other (antagonism) in the uptake.

Good, properly matured and stored compost actually contains everything we need to cultivate cannabis. We can forget about the marketing from the cannabis industry.

Useless products like bottled phosphorus, we can forget, bottled Ca-Mg, we can forget, the list would be long.

I water my plants with pure water from a reverse osmosis system, what the plant needs, it finds in the soil. I make sure that the soil is permeable to air and not too compressed. The soil must be able to breathe, water that seeps slowly brings oxygen and carbon dioxide into the soil.

My recycled Soil, after a year of rest and maturation in the cellar.

View attachment 18782031

As photosynthesis increases, the plant utilizes more nutrients, growth increases with supply. m the range of optimum temperature in conjunction with high illumination, the amount of nutrients should be increased;
low soil temperature lowers nutrient uptake → supply must be reduced!

High salt content increases the salt concentration in soil and substrate, in extreme cases salt damage can occur;
special attention must be paid to sodium and chloride content;
existing nutrients may have to be counted towards fertilization; soft water (< 8° dH carbonate hardness) lowers the pH, hard water increases it, possible consequences are determination or undesired release of nutrients.

The nutrients whose study is of greatest importance are nitrogen (N) and potassium (K). They are taken up by the plant in the greatest quantity and their optimum range in the plant (especially nitrogen) is relatively narrow, so that deficiency or excess nutrition is visibly apparent even with small deviations from the optimum.

Nitrogen nutrition is influenced by the humus content of the soil or substrate in addition to fertilization. Humic mineral soils and substrates supplied with organic fertilizers or containing compost are biologically highly active. Mineralization of organic matter initially releases plant-available mineral nitrogen as ammonium, which is converted to nitrate within a few days. Prerequisites are a slightly acidic pH and normal oxygen supply.
The conversion rate increases with increasing heat supply, so that excessive levels can occur in the summer months. Nitrogen fertilization should then be interrupted. In non-active or low-active substrates (white peat / clay mixture), these difficulties do not occur to the same extent.

In contrast, the effect of phosphate is less critical, since the optimum range is very wide and excess symptoms do not occur in practice. Often greenhouse soils are oversupplied with phosphate, so that fertilization can be dispensed with even for several years. The high contents are based on the behavior of phosphate in the soil. Depending on the pH value, insoluble salts are formed over a longer period of time, namely iron and aluminum phosphate in the acidic range, calcium phosphate in the weakly acidic to alkaline range. All compounds accumulate in the soil and are not washed out. Besides iron, other trace nutrients such as zinc, boron, copper and manganese are affected by the fixation in the acidic range.

Nutritional disorders frequently detected by soil analysis concern the potassium/magnesium ratio. A balanced equilibrium exists in mineral soils at a ratio of 2 to 3 : 1. Because of the intensive rooting of pots, nutrient ratios are less important, but observance prevents serious fertilization errors. Higher magnesium contents inhibit potassium uptake, high potassium contents inhibit magnesium uptake.

It should also be noted that a wide nitrogen/potassium ratio caused by excess nitrogen will result in relative potassium deficiency. Although the potassium content in the plant is at its optimum, it falls into relative deficiency due to excessive nitrogen fertilization. If, according to a soil analysis, the nutrient ratios are balanced, they will only remain harmonious if fertilizer is applied according to the nitrogen/potassium ratio specific to the plant.

Calcium and magnesium deficits and blockages

The discussions and confusion in grower circles speak for themselves on this topic.

In good soil mixtures with compost there can be no shortage!

There are blockages, imbalance of nutrient ratios, pH value, etc., I have repeatedly pointed out in previous chapters.

Leave the bottles of miracle products on the shelves, who bought a good mixture of primary rock flour, has no problems for years if he recycles this soil again and again.

In purchased soil, even special cannabis soil, a handful of primary rock flour is enough to exclude deficiency. It is anyway the lack of magnesium that is often the cause besides blocking (see above).

Once again as a repeat!

Depending on the condition of the soil, the trace elements are susceptible to precipitation. This means that they can no longer be absorbed by the roots. In fertilizers they are therefore often processed as chelates (organo-metal complex). This protects them from blockage in the soil.

The balance between anions and cations

Under normal conditions, plants prefer to take up cations, i.e. positively charged ions, rather than the anions nitrate, phosphorus and sulfur, which are more important for nutrition.

As a result, the plant's internal charge ratios become imbalanced. To compensate, it releases hydrogen H + through the roots to the soil or substrate. This lowers the local pH value in the soil. In addition, the cations potassium K + , magnesium Mg ++ , calcium Ca ++ and ammonium NH 4 + bound to clay particles dissolve and are thus available again for the plants.

Reference

Hortipendium (German Language)

Hauert (German Language)
I call that ion exchange ‘sparking’. It can be observed and measured with a single pH probe like this one:

74F8F277-5666-4B8F-B64B-DD836335C747.jpeg

The reading with an active root system reads way acidic, even though the soil is pHd over 8.

E601448F-35EE-4197-AC44-75CC7311EC1B.jpeg
 

[Maschinenhaus]

Active member
Special - Stomata & VPD

Vapor pressure deficit (VPD) is one of the most important factors influencing plant transpiration. It is therefore an important aspect of the water and, indirectly, the carbon cycle. The geophysical principle has long been known, but its increase in recent years has drawn the attention of ecophysiologists.

The stomata in the leaves take up CO2 during photosynthesis and release water vapor and oxygen into the environment. When humidity is too low, the stomata close to prevent the plant from releasing more water vapor than it can absorb, as cell pressure drops. This also reduces photosynthetic efficiency and, accordingly, the formation of assimilates.

Low evaporation over a longer period of time thus leads to poor nutrient supply to the plant. For this reason, the stomata in greenhouse crops should be open as much as possible at all times - even at night - to allow evaporation. The value of humidity depends on the temperature. The higher the temperature, the more water the air can absorb.

Why is the VPD important?

Numerous studies have been conducted on plant responses to high temperatures, drought, and elevated CO2 concentrations. But little is yet known about how high VPD affects vegetation dynamics. What is certain is that it affects plant physiology independently of other climate change-related factors.

In addition to direct effects on plants, a high vapor pressure deficit accelerates evaporation on wet soils. This leads to a vicious cycle of soil drying, land surface warming, and water stress for plants.

All of these mechanisms make VPD a major influence on global water resources and vegetation water stress.

High VPD usually causes plants to close their stomata to minimize water loss and avoid embolism in the water-bearing vessels (cavitation). This occurs at the expense of reduced carbon uptake by photosynthesis. At the same time, transpiration increases up to a certain threshold beyond which it remains high or begins to decrease. This can further increase plant water stress.

Photorespiration

On the one hand, photorespiration ensures that the phosphoglycolate produced by Rubisco is regenerated and thus continues to be available as a C3 body. Problems can arise with photosynthesis, especially on hot days, when photosynthesis is running at full speed in strong sunlight and the plants simultaneously close the stomata due to strong evaporation.

Then there is a CO2 deficiency and the Calvin cycle comes to a standstill, while photosynthesis continues due to light irradiation. This results in a lack of ADP and NADP to which energy can be transferred. The result is a kind of "jam" of incoming electrons, which can damage the chloroplasts.

Photorespiration grabs energy by consuming ATP and NADPH so that they can again absorb the energy of the light reaction. Thus, photorespiration has an important role because it protects the plant from damage.

Abiotic factors

Abiotic factors include all influences emanating from the inanimate environment. These are therefore environmental factors in which living organisms are not directly involved. The abiotic environmental factors of an ecosystem include the following:

- Temperature
- Light
- Water (quantity and composition)
- Climate (including humidity, solar radiation)
- pH value
- concentration of substances (e.g. nutrients, salts, toxins)
- Weather (e.g. wind, lightning, precipitation)

Abiotic factors affect the life of all living things, i.e. animals, plants, fungi and bacteria. For example, they influence the mating season of animals or the fall of leaves on trees.





Reference:

VPD tables

 
Last edited:

[Maschinenhaus]

Active member
Chapter 14

Ion exchange


An important property of soils for plant nutrition is their ability to reversibly (exchangeably) bind (adsorption, desorption) ions, molecules, organic substances (including pollutants) and water to their solid substances (mineral and organic), since the surfaces of the solid substances are electrically charged.

Nutrient ions important for plants, such as Ca2+ (calcium), Mg2+ (magnesium) or Na+ (sodium), can thus be bound to the surfaces of the solid substances and released back into the soil solution by other ions replacing them.

This is therefore also referred to as ion exchange (see diagram). The electrically charged solid substances or soil particles thus act as ion exchangers. For the plants, this has the great advantage that nutrients are not immediately washed out of the root zone by the seepage water, but can be absorbed more or less continuously from the soil solution.

Ion exchanger

In particular, mineral and organic soil components < 2 µm (= soil colloids) with a high specific surface area (internal and external) are able to do so and contribute mainly to the overall charge of the soil. These include mainly clay minerals, especially expandable three-layer clay minerals (e.g. illite, montmorillonite), and humic substances, and to a lesser extent oxides and hydroxides. These solid substances can be described as reservoirs or stores for plant nutrients (and also for pollutants). They include both cations (positively charged ions) and anions (negatively charged ions). Negatively charged exchangers are called cation exchangers and positively charged exchangers are called anion exchangers. The exchange of ions takes place as a process between the soil solution and the solid substances.

Due to their internal structure, clay minerals (= phyllosilicates) are usually negatively charged. Only lateral fracture surfaces have a variable charge. The reason: The basic structure of the silicates is the SiO4 tetrahedron, consisting of a central silicon ion and four oxygen ions. During the formation of clay minerals, however, it often happens that the central silicon ion (Si4+) is replaced, for example, by an aluminum ion (Al3+) (= isomorphous replacement), resulting in a charge deficit (negative charge).

To balance the charge, cations (e.g. Na+, Ca2+) are reversibly added. The negative charge is independent of the pH of the soil solution. Clays therefore have a predominantly permanent charge and are thus cation exchangers. In humic substances, the negative charges are due to COOH and phenolic OH groups, from which protons (H+) are split off with increasing pH (dissociation). In extremely acidic environments (<pH 3), organic soil colloids can become anion exchangers as a result of proton accumulation.

They therefore possess a variable charge, just like oxides and oxide hydroxides. If soils contain a high proportion of expandable clay minerals and humic substances and the pH values of the soil solution are between 3 and 8 (e.g. soils of the humid cool temperate climate zone), anion exchange does not play a significant role because of the predominantly negative charges of the exchangers. Cation exchange predominates.

Exchange process

In an ion exchange, lower-order ions are displaced from the exchanger by higher-order ions because of the stronger Coulomb force (electrostatic attraction forces): Al3+ displaces Ca2+ and Ca2+ displaces Na+. In anion exchange, for example, PO43- (phosphate) displaces SO42- (sulfate). For the same valence, the ion with the greater molar mass (M) displaces the ion with the lower.

For example, K+ (39 g/mol) displaces Na+ (23 g/mol). The exchangeable cations are surrounded by a hydrate shell. Among equivalent cations, the diameter of the hydrated ions is crucial (ion size). The thinner the hydrate shell, the better the attachment to the exchanger: Mg2+ > Ca2+ and Na+ > K+. These sequences are called selectivity. The type of cation ion exchanger (clay minerals) also plays a role in the exchange. For example, montmorillonite prefers Na+, K+, whereas kaolinite prefers Mg2+ and Ca2+. If only the ion properties are taken into account, the following series results with regard to exchange strength and adhesive strength: AI3+ > Ca2+ > Mg2+ > K+ > Na+.

Exchange capacity

The sum of all exchangeable cations of a soil is the cation exchange capacity (CEC). The unit of measurement of the CEC is mmolc/kg (mmol = 0.001 mol, c = charge). A distinction is made between the potential cation exchange capacity (KAKpot) and the effective cation exchange capacity (KAKeff). The KAKpot indicates the maximum achievable exchangeable amount of cations of a soil under optimal conditions (pH 8.1 according to DIN ISO 13536) (maximum number of possible free cation binding sites).

The KAKeff indicates the actual number of free cation binding sites at the current pH value of a soil. The higher the proportion of organic exchangers in the soil and the higher the pH of the soil, the greater the KAKeff. In acidic soils (pH <7), the KAKeff is always lower than the KAKpot because H+ ions occupy exchanger sites to the detriment of cations. The ratio of basic cations to the total percentage of all cations in the exchangers is called base saturation (BS) (in %). In carbonate-rich soils (e.g., rendzina, terra fusca), base saturations approaching 100% are often reached, which means that Ca2+, Mg2+, K+, and Na+ ions are almost exclusively involved in the KAK. Base saturation is an indicator of soil quality. If the proportion of basic cations is more than 70%, there is a high base saturation, and below 35%, a low base saturation.







Reference


 

[Maschinenhaus]

Active member
Chapter 15

How plants perceive invisible light - UV-A and UV-B


Specialized photoreceptors enable plants to use light that is invisible to us. Structural analyses of the recently discovered UVR8 receptor show how ultraviolet light signals lead to the conversion of the light receptor. In this way, the plant gives the signal to initiate an important protective program.

By perceiving light, plants control growth, germination, flower formation, and control over their diurnal and nocturnal rhythms. In order for plants to actually "see" light, they have photoreceptors specialized for different light spectra. The best-known photoreceptors are the so-called phytochromes, which measure the ratio between light and dark red light. They control important developmental processes in plants, such as seed germination and the greening of plant parts.

However, plants can also perceive light that is invisible to us. Studies in the 1970s already showed that plants produce sunscreen-like protective factors when irradiated with ultraviolet (UV) light. They are part of the so-called UV-B signaling pathway, which the plant uses to protect itself from the harmful effects of UV radiation. These negative effects include, for example, DNA damage and reduced photosynthetic efficiency. For a long time, the light receptors that trigger the UV-B signaling pathway were not known. Only recently was the UV receptor UVR8 discovered to be part of this signaling pathway. However, it remained unclear how exactly the receptor takes up the UV light and transmits the signal to the cell.

With structural analysis of the UVR8 receptor of Arabidopsis thaliana, scientists have now shed light on how UVR8 functions as a UV sensor. In plant cells, UVR8 receptors exist in two structural states: A light form and a dark form. In darkness, the ring-shaped UVR8 molecule forms a bond with a second UVR8 molecule. The two doughnut-like molecules are held together like a sandwich by salt bridges and aromatic amino acids. When the plant is irradiated with UV light, the doughnut sandwich breaks down again into two individual molecules. These are then free to bind with other protein partners. In the case of UVR8, the factor COP1, which is responsible for initiating the genetic protection program, binds.

The switching back and forth between the single and the double molecule is made possible in the UVR8 receptor by a special structural feature that distinguishes UVR8 from all other photoreceptors known so far: Instead of the chromophore structure typical for photoreceptors, it has an amino acid pyramid consisting of tryptophan residues on its contact surface. When stimulated by UV light, the electrons of these amino acids are excited and transferred to neighboring amino acids. In this way, charges holding the two molecules together are neutralized and the UVR8 molecules separate. Accordingly, the tryptophan pyramid is the crucial UV light sensor that captures light and transmits the absorbed light energy.

UVR8 is also found in original plants, such as mosses and algae. Scientists therefore suspect that the receptor helped plants survive early in Earth's history, when the planet was exposed to greater amounts of radiation from ultraviolet light.

The structural remodeling of the receptor triggered by light signals could also inspire biotechnologists to create new tools. Proteins whose architecture is specifically controlled by light irradiation are now valuable tools in cell biology research. Photoswitchable molecules can be used to track processes in living cells and assign them to specific organs. As the researchers' experiments show, mutations in the tryptophan pyramid can even shift the absorption spectrum of UVR8.

Grow light spectrum

Grow light spectrum refers to the electromagnetic wavelengths of light produced by a light source to promote plant growth. For photosynthesis, plants use light in the PAR (photosynthetic active radiation) region of wavelengths (400nm-700nm) measured in nanometers (nm).


Nanometers are a universal unit of measurement but also used to measure spectrum of light – humans can only detect visible light spectrum wavelengths (380-740nm). Plants, on the other hand, detect wavelengths including our visible light and beyond, to include UV and Far Red spectrums.


It’s important to note light spectrums affect plant growth differently depending on things like environmental conditions, crop species, etc. Typically, chlorophyll, the molecule in plants responsible for converting light energy into chemical energy, absorbs most light in blue and red light spectrums for photosynthesis. Both red and blue light are found in the peaks of the PAR range.

Read more



Different spectrum colors serve different purposes in the growth and development of the cannabis plant. Light, which is one of the most crucial factors in cannabis cultivation, comes in different colors. How does one know which spectrum to choose? Do we know how specific wavelengths shape our plants or affect their flower quality? Well – we know quite a bit, but a lot is still unknown.

Here’s what we know so far.

UV-A light

Spectrum_of_Light.png


UVA light has been shown to increase secondary metabolite activity in many plants, and this is also the case with cannabis. The most important secondary metabolites from a cannabis grower’s perspective are cannabinoids such as THC and CBD, as well as terpenes which give cannabis its distinctive aroma. Short wavelength irradiation, such as UVA and blue light, trigger the plant’s stress response system and the plant starts to protect itself from the abiotic stress i.e. short wavelength irradiation. Increased stress level results in increased metabolite activity and therefore higher THC accumulation in flowers, when compared to light sources lacking UVA or blue light (Magagnini et al. 2018).

As plants cannot move, they read signals about their surroundings from temperature, light spectrum, soil moisture content, etc. Short wavelength irradiation, such as blue and UVA light give the plant a signal that it is under a clear sky without competition from the neighboring plants. A no-competition environment indicates that the plant it is in no hurry to re-produce (make seeds) or stretch towards light. Plants which are grown under rich blue and UVA spectrum often have short internodes, small leaf area, and thick leaves. These responses can be reversed by green or far-red light, which induce shade-avoidance-syndrome symptoms such as stretching of the stem, increased leaf area, and enhanced flowering. Therefore, by adjusting the amount of blue and UVA in the light spectrum into a perfect balance in relation to other wavelengths, we can manipulate the size and biomass accumulation.

Perhaps it then comes as no surprise that in the nature, the most potent cannabis plants are typically found on high altitudes of mountain regions. In such areas plants have unobstructed access to an abundance of clear sunlight whose spectrum is higher in UV wavelengths than at lower altitudes.

Effects of UV Light on Cannabis

There are certainly a lot of stories, myths, and rumors about UV. Valoya’s research efforts in this field combined with data from scientific literature should help growers better understand what UV does to cannabis.


The effect of UV on cannabinoids was first presented in an academic paper by Lydon et al. 1987. Lydon and his team concluded that UVB increased the floral THC concentration, however other cannabinoids were not affected by the UV exposure. Note that this paper talks about UVB (280-315nm) which is very intense radiation and typically not used in horticultural lighting.

How Does Cannabis React to UV?

In some horticultural light spectra, such as the Valoya NS1 and Valoya Solray385, the type of UV used is UVA (radiation between 315-400 nm). A little bit of UVA creates gentle stress that drives the plant to develop better defense mechanisms – cannabinoids.

However, a little too much and we will stunt the plant’s growth and it will underperform. Valoya has tested UVA LED chips of different peak wavelengths to find the sweet spot where we get maximum cannabinoid output, without harming the plant’s natural processes.

According to our studies, we can optimally increase the floral and leaf cannabinoid concentrations in cannabis by using the 385 UVA wavelength. Note that, even though this is actual UVA light, that it is very mild and would not have adverse effects on humans exposed to it.

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[Maschinenhaus]

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Chapter 16

Cannabis sativa and Cannabis indica vs “Sativa” and “Indica”

Although cannabis is legalized and accepted as an agricultural commodity in many places around the world, a significant lack of public germplasm repositories remains an unresolved problem in the cannabis industry.

The acquisition, preservation, and evaluation of germplasm, including landraces and ancestral populations, is key to unleashing the full potential of cannabis in the global marketplace. We argue here that accessible germplasm resources are crucial for long-term economic viability, preserving genetic diversity, breeding, innovation, and long-term sustainability of the crop.

We believe that cannabis restrictions require a second look to allow genebanks to play a fuller and more effective role in conservation, sustainable use, and exchange of cannabis genetic resources.

From wild marijuana to Landraces

Cannabis is one of humankind’s oldest domesticated crops, first mentioned in writing in 2900 B.C. by the Chinese emperor Shen-Nung, who included cannabis in an encyclopedia of plant medicines. Other archaeological findings have discovered traces of hemp rope and imprints of cannabis on broken pottery tracing back to 10,000 B.C. in China’s Neolithic period.

Botanists can trace cannabis genetics to a single plant species originating in modern-day Afghanistan’s Hindu Kush mountains. This first wild cultivar of cannabis was coveted for its use in rope and clothes-making as well as medicinal practices and quickly expanded from its original region.

Researchers later found evidence of cannabis in Ancient Greek and Roman artifacts. At the same time, Germanic tribes brought it farther west, and the Ottoman empire spread the plant south into the African continent. In the 16th century, Europeans crossed the Atlantic and planted cannabis in the Caribbean and Central Americas, where it spread west and south.

Cannabis flourished everywhere, with each plant adapting its physical and chemical characteristics depending on the environment in which it found itself. These first landrace strains, named for where they grew, are now distinguishable and cherished for such traits.

Highly adaptable, marijuana plants have managed to develop in different parts of the world adapting to different environmental conditions. Their origins are not entirely known; some palaeobotanical studies – the science that deals with plant remains form the past –, link them to the Himalaya, from where cannabis spread across the globe. Mankind had a considerable hand in this process, as merchants, who carried cannabis seeds in their travels, appear to have spread it from Central Asia to the rest of the world. This is how cannabis was disseminated across Africa’s Middle East and Southeast Asia in the period from 2000 to 500 years ago. It equally reached America in 1545 and Australia in 1788.

Even before man started cultivating marijuana, the plant grew wild in nature in the form of the so-called “wild relatives”. Cannabis grew spontaneously in the environment, without being cultivated. This means wild marijuana populations were not domesticated, that is, they were not shaped trough a selection processes and therefore there was more diversity in terms of morphology. The plant, though, did fix some traits through its evolutionary process in interaction with the environment, adapting to its environmental conditions.

The first breeding process carried out by man we know about took place 6500 years ago in Mongolia, a finding released by Russian botanist N. I. Vavilov. Although there is evidence that this was the first time cannabis was bred and domesticated, studies suggest this practice was most common in China.

Be that as it may, this was a major step in the history of cannabis genetics, as local growers started to shape the cannabis populations they grew in their fields. Through selection, traditional growers gradually eliminated the individuals that because of their morphology did not meet the desired parameters (smell, size, yield, vigour, etc.). This is how growers gradually shaped the cannabis populations giving way to what we now know as landrace strains.

Incredible as it may seem, there are pollen, seeds, fibre and trichome fossil remains – all charred – that have been recovered and used to create a chronological timeline of cannabis throughout history, a plant mankind has used since ancient times either for medicinal, recreational, textile or religious reasons.

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The formal botanical taxonomy of Cannabis sativa Linnaeus and C. indica Lamarck has become entangled and subsumed by a new vernacular taxonomy of “Sativa” and “Indica.” The original protologues (descriptions, synonymies, and herbarium specimens) by Linnaeus and Lamarck are reviewed. The roots of the vernacular taxonomy are traced back to Vavilov and Schultes, who departed from the original concepts of Linnaeus and Lamarck.

The modified concepts by Vavilov and Schultes were further remodeled by underground Cannabis breeders in the 1980s and 1990s. “Sativa” refers to plants of Indian heritage, in addition to their descendants carried in a diaspora to Southeast Asia, South- and East Africa, and even the Americas. “Indica” refers to Afghani landraces, together with their descendants in parts of Pakistan (the northwest, bordering Afghanistan).

Phytochemical and genetic research supports the separation of “Sativa” and “Indica.” But their nomenclature does not align with formal botanical C. sativa and C. indica based on the protologues of Linnaeus and Lamarck. Furthermore, distinguishing between “Sativa” and “Indica” has become nearly impossible because of extensive cross-breeding in the past 40 years. Traditional landraces of “Sativa” and “Indica” are becoming extinct through introgressive hybridization. Solutions for reconciling the formal and vernacular taxonomies are proposed.

What Is Landrace Cannabis?

Thousands of cannabis strains currently exist on the market, presenting consumers with more variety of choices than at any other point in history. While there’s a strain for everyone, all cannabis today traces its genetic history back to a few original varieties, known as landrace strains.

A landrace cannabis strain is a plant grown in its native environment and geographically without hybridization with other cannabis strains. Often named for their place of origin, original landrace strains were eventually domesticated by humans and transported over the centuries to various regions, which resulted in changes to their physiological and chemical structure.

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