Chelates for trace minerals?

[milkyjoe]

Michael...how do you feel about trying to time the application of K? For example if you are growing fruit is there any advantage to waiting until the fruit begins to fill and then drip/foliar applying extra k. Part of the theory being not having that much in the soil during the vegetative state allows better uptake of Ca. The stuff nova crop control is talking about.

And do flowers become k sinks...specifically when we start to set bud on our non pollinated plants do you think k demands go up?

I also have some brix related if you don't mind me going off on tangents.

 

[m_astera]

milkyjoe-

I haven't tested or seen tissue tests for K or other mineral uptake for cannabis leaves and buds during the growing season. Many plants do take in extra K during fruit set; for the most part that results in forming sugars, starches, and oils (as opposed to proteins).

K is highly mobile in plants (unlike say Ca) and plants will often relocate it from older leaves to young leaves if there is a K shortage in the soil. K deficiency shows up as yellowing and crisping of the leaves starting at the edges, mostly on older leaves.

In my experience there is seldom a problem with K deficiency as long as the K level is 4% to 5% of CEC saturation with a bare minimum of 100 ppm K even in a very low CEC soil. If K is loaded onto the soil colloids and exchange sites at this level the crop should be able to access plenty of K throughout the growing season, in other words it can take what it needs whenever it needs it. If the soil doesn't have that K available then adding it via drip would probably be the best approach as the roots will have no problem absorbing it and bringing it to the leaves.

K should not interfere with Ca uptake as long as it is in the range of 7% or less of CEC saturation and Ca is at 70% or so. Unfortunately some growing media have high or excessive amounts of K to begin with. I have a lab analysis for coco coir in my files that shows 30% K, 20% Mg, and only 24% Ca saturation. When it is in excessive amounts like that, plants take up K preferentially whether they need it or not, so if one is using coco fiber they would be wise to make sure their mix has plenty of Ca, and that the Ca has had time to find its place in the growing media before planting.

This would be a good subject for an experimental trial, to see what (if any) difference adding extra K at bloom time makes in production and quality. Probably no difference if the growing media was already high in K.

I'd be glad to discuss Brix.

 

[milkyjoe]

What I am curious about is if mobile elements like k have a bigger effect on brix than Ca. It seems to me K would remain present in the sap and contribute to refraction where Ca will be in the tissue of the plant. So in your coco example could you get a false high brix reading even though that plant would obviously not be as healthy as it could be?

I further wonder if too high a reading, in the leaf...not the fruit, might be an indication of this. In other words is there a goldilocks brix for leaves?

Btw...where I see that high K bcs is from compost. People on here use 25-33% and it invariably drives K to 10-20%.

Thank you for your time

 

[m_astera]

milkyjoe-

Plant Brix is of course the total dissolved solids in the sap and is largely sugars/saccharides. Carey Reams, who introduced the use of the Brix refractometer for measuring crop quality, claimed that the higher the Brix the higher the mineral content. I have seen little evidence to back that up, but as a general rule a plant with a high sap Brix in the leaves will be more insect and disease resistant. 12* Brix with a sap pH of 6.4 to 6.5 seems to be the Goldilocks number.

Sap from crops with a high Ca content will show a fuzzy line on the refractometer scale; it seems to be only Ca that does this. I assume that the crushing of the plant is extracting some Ca from the cells themselves, though there will surely be Ca in circulation in the sap as well; Ca only becomes immobile once it is part of the cell structure.

You might be interested in a blog entry I wrote a few years ago, where I took Brix readings of things like battery acid, gin, and laundry soap:

http://thenewagriculture.blogspot.com/2010/03/part-v-is-high-brix-enough.html

The real question about high K in cannabis would be what effect it has on the overall quality and complexity of the resins produced. High K in food crops like corn (maize) or fruit generally means lots of simple sugars and starches with lower amounts of complex saccharides, vitamins, trace minerals, and proteins. That may be fine for cannabis, I really don't know. But I suspect that cannabis grown with lower amounts of K and higher amounts of Ca and secondary and trace elements would be more complex and have different psychoactive and medicinal properties.

 

[milkyjoe]

Excellent blog. The more i thought about it the less sense it made.

My guess is essential oils are also long carbon chains. My quest is the mineral nutrtion to support the enzymes that catalyze those long chains. I don't have scientific proof...but antedotally it makes a sgnificant differnce

 

[m_astera]

There is some correlation between high Brix and high mineral and nutrient content. Soils with a full and balanced amount of minerals will generally grow higher Brix crops from the same seed, and the crops will contain higher amounts of a wide range of essential minerals. But there is no good evidence that just because a plant has a high Brix reading that it is a good source of mineral nutrients.

 

[milkyjoe]

So hopefully before you get sick of my questions one more batch. Do you have a good method for determining the weight of potting soils? Should the weight of perlite be factored out since it doesn't contribute to cec?

And regarding trace elements like B...if you are short do you try to make it up over several grows or do you add it all at once?

 

[cyat]

m astera...
What do you think is a good way to get all that calcium into the plants/soil? gypsum?

 

[Cep]

Michael,

When you get to 50 posts you'll be able to receive private/public messages on your own page. I'd have more questions for you but they will get further away from this threads subject. You might be interested to check out the thread I started:
https://www.icmag.com/ic/showthread.php?t=283577

I'm seeing high brix readings (15-18.5) that could be caused by high Potassium levels as Milkyjoe theorized. Some readings have cloudy lines, most are sharp.

Good to see professionals on this forum!

Cyat,

Gypsum is great, super soluble, low salt index, fast Calcium delivery.

 

[m_astera]

milkyjoe-

I'm glad to answer any questions. I've been wanting to spend some time on this forum since I signed up in 2010, finally finding the time.

Agreed on the perlite, it is non-functional as a nutrient source so should not be counted in soil weight. It's best to oven-dry the other soil/media components and then weigh a given volume of them. To make it easy on myself I'll just cut and paste from The Ideal Soil V2.0 p78:
~

Working With Lightweight Mixes and High Organic Matter Soils
The figures above are close enough for heavy mineral soils, but naturally
high-organic matter soils such as peat soils or virgin forest soils may weigh much
less than 92 lbs per cubic foot or 1333 kg per cubic meter. Lightweight potting
media may weigh as little as 10 lbs/ft^3 (270 lbs/yd^3) or 150 kg/m^3.

If you are working with a light weight soil, potting media, or compost/organic matter
it is best to measure and weigh an oven-dry sample [dried at 250*F or 120*C].
Lightly pack a 1 gallon or a 4or 5 litre container with the dry sample and weigh the soil (of course subtracting the weight of the container).

Calculating the Amount Needed Per Cubic Yard: Lightweight Soils
There are 7.48 (~7.5) US Gallons (128 fluid oz) per cubic foot and 201.96 (~200)
gallons per cubic yard. If a gallon of soil weighs 2 lbs, a cubic foot will weigh 7.5
gallons x 2 lbs = 15 lbs. At 200 US gallons per yard^3, 2 lbs x 200 gallons = 400 lbs
per cubic yard.

Once we know the weight per cubic yard we can calculate how many pounds or
fraction of a pound equals 1 ppm. The cubic yard of growing media above weighs
400 lbs. One-millionth of that: 400 lbs / 1 000 000 = 0.004 lbs; 4 thousandths of a
pound. A good digital scale can weigh that amount, but it’s awkward. We could
choose to work with ounces and decimal fractions of an ounce:
1 lb = 16 oz, so 0.004 lb x 16 = 0.64 oz
but it’s usually simpler and easier to convert the pound weight to kilograms and
grams for small amounts of soil media or amendments
Our cubic yard above weighed 400 lbs. 1 kg = 2.20 lbs.
Divide 400 lbs by 2.2 kg/lb = 182 kg per cubic yard.
A kilogram is 1000 grams. There are 1000 milligrams in a gram.
1000 x 1000 = 1 million. A milligram is 1 ppm of a kilogram.
Our worksheet says we need 300 ppm Calcium. For each kilogram of weight, we
need 300 ppm or 300 milligrams (0.3 grams) of Calcium.
Multiply 182 kg x 0.3 grams/kg = 54.6 grams of Calcium needed per cubic yard.
Calculating the Amount Needed Per Cubic Meter
There are 1000 liters per cubic meter. The 5 liters we talked about weighing
above are equal to five thousandths or 0.005 of 1 cubic meter. If 5 liters of soil
weighs 1 kg, the weight per cubic meter would be 1 kg / 0.005 = 200 kg.
200 kg x 0.3 gram/kg = 60 grams of Calcium needed per m^3.
~~ (end quote)

As long as the amount of Boron being added doesn't raise B above 1/1000th of the amount of exchangeable Calcium measured with a Mehlich 3 soil test, there is no problem adding whatever amount is needed in one dose. Also worth noting, plants love Boron and will suck it right up. If you are growing in the same soil, you can count on having to add B each growing season.

 

[m_astera]

m astera...
What do you think is a good way to get all that calcium into the plants/soil? gypsum?

Yes, gypsum is good for making Ca available. The same thing can be accomplished by balancing the base cations Ca:Mg:K to the Albrecht ratios of approximately 70%Ca, 10-15%Mg, 4-5% K (as percentage of CEC) and then ensuring that Sulfur is at least 50% of K by weight. For example, if "Ideal" K is 200ppm, Sulfur should be at least 100ppm and up to 200ppm in a high-Ca soil.

The best way to ad S is in sulfate form, SO4, already combined with a base cation. So, it can be added as Ca, Mg, K, Fe, Mn, Cu, or Zn sulfate or a combination of them, whatever the soil needs.

If adding the elements above won't bring S high enough, then elemental Sulfur may be used. If the soil temperature is above 60*F (15*C) soil bacteria will convert the elemental S to SO4, which is what plants use.

Optimum levels of both Boron and Sulfur are needed to mobilize Calcium into the plant.

 

[m_astera]

Michael,
<snip> You might be interested to check out the thread I started:
https://www.icmag.com/ic/showthread.php?t=283577

I'm seeing high brix readings (15-18.5) that could be caused by high Potassium levels as Milkyjoe theorized. Some readings have cloudy lines, most are sharp.

Good to see professionals on this forum!

Cyat,

Gypsum is great, super soluble, low salt index, fast Calcium delivery.

Cep-

Thanks for the kind words.

I read your well done thread, nice pics. I will leave a comment re Brix, sap pH, and K there. [link in quote above]

 

[Bulldog420]

Last year I was getting brix readings in the 20's. Was I doing something wrong when taking the reading? Hard to believe my plants were any healthier than Ceps.

 

[Photosynthesis]

The problem I see with trying to apply "soil balancing" methods to cannabis growing is that there are 0 base lines for this crop.

Reems, Albrecht, etc.. are Dogma's. There "conclusions" are up for debate. There does seem to be some science in both of what they speak of, but some of it is majorly debatable.

Brix, and Albrecht's ratios are very much up for debate.

Are soil tests a good thing? Hell yes they are. The problem lies in trying to reamend the soil for the optimal plant nutrition of Cannabis.

Especially with indoor crops. The short cycles make it more than an interesting process.

I have yet to speak with an agronomist that had decades of experience with applying "soil balancing" methods specifically related to the growing of cannabis. Followed up with tissue tests, soil tests, and chemical analysis of thc, cdb, terpenes, etc.

We are just at the very beginning of this process. Give it 10 more years, and we may have some "definitive" conclusions.

Albrecht loses me with the "generalized" ratios for growing plants. Reems loses me with the varying readings of brix levels throughout the cycle of the plant.

There are however a million ways to skin a cat.

 

[m_astera]

Photosynthesis-

In 2000 I started a research effort to advance our knowledge of soil mineral balance beyond where Albrecht left off, i.e. at a CEC saturation of around 70%Ca, 15%Mg, and 5%K. After reading all of the books by Albrecht, Reams, and their followers I was still left with no real knowledge on how to balance even those three minerals, much less the other 8 mineral elements measured on most soil tests.

Eight years later, in 2008, I published The Ideal Soil, the first book to show exactly how to read a soil test and balance the major cations and anions along with B, Fe, Mn, Cu, and Zn. Since then, the book has gone around the world and the principles have been successfully applied to any crop imaginable in all climates. There is absolutely no need to do anything different for cannabis. Cannabis is a normal crop that grows best in the same mineral balance that grows the best cabbage, corn, and tomatoes.

The only crops that need a different mineral balance are plants native to highly-leached forest soils where much of the Ca has gone south, leaving behind a high Mg soil. Those include blueberries, coffee, holly, azaleas, rhododendrons, and cacao, all of which do best in a high-Mg high-S soil. pH has nothing to do with it.

As I'm posting on IC, it's worth mentioning that I have been and continue to work with cannabis growers around the world, including a number of people who read and post here. There have been no complaints; the Ideal Soil method works across the board.

Here are the essential ratios for balancing soil minerals, based on a Mehlich 3 soil test for soils with pH <7, or a Mehlich 3 + an Ammonium Acetate 8.2 test for soil pH 7 and above:

Ca = 65-85% of CEC saturation
Mg = 10-20% of CEC saturation depending on soil texture
K = 4%-5% of CEC
Na = 1%-3% of CEC

P = K (or P2O5 = 2x K2O)
S = 1/2 x P

B = 1/1000 x Ca
Fe = 1/2 x P
Mn = 1/3 to 1/2 x Fe
Zn = 1/10 x P (up to 50 ppm)
Cu = 1/2 x Zn

 

[cyat]

Micheal glad to have you here sharing your knowledge, thank you!

I see youre focusing on mineral balance, which also includes k, but what about nitrogen and phosphorus?

 

[Photosynthesis]

Michael, You should sign up for MicrobeMan's forum. There are many different advanced organic agriculture techniques being discussed there.

You may very well find it of interest.

 

[MJBadger]

DreamBig , everything you are looking for plus some is found in stinging nettle . It has many trace elements , high iron & nitrogen .

There are several threads on here with all the info .

 

[m_astera]

Photosynthesis-

I will probably check out microbeman's forum, but let me state upfront: Microbes do not create minerals. If they are not in the soil, they will not be made available by microbes or anything else.

I'll add that there are ate least 1000 people blabbing about microbes for every one who knows the first thing about minerals.

 

[milkyjoe]

You might like microbeman and his buddies...they share your feeling about elaine. Balancing...not so much.

For what it is worth I am ordering your book. Leaned a lot from this and ceps thread from you already and it rings true with my experiences