Watering pH in Organic Soil Based Systems
...doesn't matter. In fact, the guidelines of watering with a pH around 6.5 could actually harm your plants in certain circumstances.
It doesn't matter because there is a huge colony of bacteria and fungi living in your soil, and you feed them, not your plant directly. They will use what you give them and the pH of the SOIL will ADJUST ITS SELF in a properly running system.
Now, I'm not saying pH isn't important, because the pH of the SOIL is very important. It's just how you feed the soil that is a lot less important, and one doesn't necessarily have the effect you'd think it does. An example is Earth Juice Nutes. Starting with water with a pH of 7 to 8, adding EJ nutes brings the pH down to 3.5-4 or so. Conventional wisdom might say this going to kill your plants, but in fact EJ nutes have a great rep. and produce a great product. I've been using them for over 10 years, and they are a great way to fine-tune your system, I add EJ in addition to castings, guanos, etc.
Now, a here's a case of hydro growers going organic... a couple of folks I'm teaching organic gardening methods to. These guys check the pH of everything, and have adjusted their watering to a pH of 6.5. Technically, perfect. Now, we started the grow with a SOIL pH of around 6.7. After watering for a while with water at 6.5, the SOIL pH is now almost exactly 7. How did this happen? Well, when you mix soil, you typically have some ingredients with low pH, and others with high pH to buffer the soil so it doesn't turn too acidic. Usually lime or crushed sea shells/coral is used for this, and it's usually balanced against peat moss, with a low pH. If you make your own soil mix, usually dolomite or hydrated lime is added for the same reason. Commercial mixes will have different levels of buffering. This is important to understand, because some commercial mixes like Fox Farm Ocean Forest has a lot of sea shell, and in the case of the hydro guys going organic, adding pH UP was too much in combination with this particular soil mix. Luckily, I make them test the soil often so this was recognized, and now they are not using pH UP and watering them with un-adjusted EJ nute mix that has a super low pH.
I have held off on posting this because it could possibly be confusing, but if you are an organic gardener your progress as a grower could be hampered by not understanding this. Organic medium is rich with life and nutrients and it's just not as simple as setting your pH and ppm correctly like hydro. You need to have some idea of what the interaction between the live soil you are using and what you feed them.
On a related subject, canned feeding programs are a horrible idea to follow in organic gardening for much the same reason. Every system uses nutes differently depending on the vigor of the plant, how much light, co2, and root area the plant has. This is another reason to buy a soil test kit. You need one to come up with YOUR OWN nute program. Without having at least a ballpark idea of what's already in your soil, how can you properly feed them? Well... if you have enough experience you might be able to just tell. If you haven't grown for years already, you might need some help. The idea is to keep the soil in balance, to do this you need to know how much nutes the plant uses in it's various stages in life, and add nutes accordingly. If you do it right, you won't have salt buildup, pH will never be a problem, you'll never have to flush (yup, that's right, if you flush, you f'ed up) and you can save a ton of money and get better results growing by re-using your soil. Re-used soil already has all the microbes you need so you won't need to spend big $$$ on these additives, and you will notice your 2nd crop on the same soil IS BETTER THAN THE 1ST. Yes, it gets better over time, and if you throw out your soil you are doing yourself and the planet a disservice. When I re-use soil I just add castings, guanos, and more lime.
Watering pH in Organic Soil Based Systems
"It doesn't matter because there is a huge colony of bacteria and fungi living in your soil, and you feed them, not your plant directly."
I take a minor issue with this. Even the worst fertilizers have plant-ready nitrates available, and the bacteria have nothing to do with those since it's already-processed into a form plants can use but bacteria cannot use. Almost every other nutrient is water-soluble, so that again isn't an issue.
The only reason you should ever have a microculture in hydro is if you are using a high urea or ammonia-based nitrate source, and if you are trying to harden plants against disease.
Also, speaking as R&D director, let me say organic is purely marketing. I've done it all from SEA-90 to Fox Farms Organic, and I've never noticed a difference in yield hydro-wise, from cannabis to tomatoes to mints to lettuces.
Watering pH in Organic Soil Based Systems
Quote:
Originally Posted by khyberkitsune
Also, speaking as R&D director, let me say organic is purely marketing. I've done it all from SEA-90 to Fox Farms Organic, and I've never noticed a difference in yield hydro-wise, from cannabis to tomatoes to mints to lettuces.
Organic is more about health rather than yield.
Watering pH in Organic Soil Based Systems
Quote:
Originally Posted by leadmagnet
Organic is more about health rather than yield.
Some of us aren't on the "Organics Rocks" bandwaggon. I use what works, Organic or not, and my plants are quite healthy.
One can be overly anal about things like this. Don't let youself get caught-up in junk science. Last I checked, there was no scholarly determinations that organic is any better or worse than overpriced organics, for your health or your plants health. The label "organic" does not mean the product is better, but those that sell you organic products sure tout superiority as they take the cash from your wallet.
A good flush and a good cure, you can't tell the difference.
Watering pH in Organic Soil Based Systems
Quote:
Originally Posted by Rusty Trichome
Some of us aren't on the "Organics Rocks" bandwaggon. I use what works, Organic or not, and my plants are quite healthy.
One can be overly anal about things like this. Don't let youself get caught-up in junk science. Last I checked, there was no scholarly determinations that organic is any better or worse than overpriced organics, for your health or your plants health. The label "organic" does not mean the product is better, but those that sell you organic products sure tout superiority as they take the cash from your wallet.
A good flush and a good cure, you can't tell the difference.
I pretty much agree with your comment, my only point being that those who strive for "organic" are taking what they believe to be a healthy approach.
To those individuals, generally speaking, yield takes a back seat to health concerns.
I do not necessarily agree with them on every aspect of the issue. Each individual needs to do their own homework and make their own decisions.
Watering pH in Organic Soil Based Systems
Actually, I just e-mailed Linda Chalker Scott (Head of horticulture at U of Washington)
Here's a copy minus my e-mail address...
From: (Rusty Trichome)
Sent: Sun 6/27/2010 8:11 AM
To: Chalker-Scott, Linda K
Subject: Organic nutrients versus chemical...
Hi. Love the myths page y'all host. Very informative.
I contacted you a couple years ago regarding moon phase gardening, in which you provided a very quick and concise response. Thank you. I've refered others to your myths page many times, and this insight has helped solve disagreements many times, and has caused a few as well.
Anyway, I do have another question I can't find a straight answer to, and hope you can help me again...
Are organic nutrients better for plants, (or the people that ingest those plants) than non-organic nutrients and additives? I'm a cannabis caretaker, and prefer not to subject my wife I'm caretaking for, for her T-cell lymphoma, to weird additives and crap. But we are not in a financial position to be spending money on expensive organics, if Miracle Grow type chemical nutrients are equally 'safe'.
Is there evidence you could point me to that would help me determine if I should pay the extra price for the organic label, or should I worry about the effects of chemical nutrient residue?
Thank you again.
Rusty Trichome.
Her response:
Hi Rusty -
Thanks for your kind words. I'm glad you've found the information helpful! (If you haven't seen it yet, check out our blog page - 4 of us taking on various gardening topics from a scientific perspective - link below.)
I did a column on organic vs. inorganic nutrients several years ago - you can find it here: http://www.puyallup.wsu.edu/~linda%2...uperiority.pdf.
Short answer: plants don't distinguish between sources of nutrients. So don't waste your money!
Linda
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~
Linda Chalker-Scott
Associate Professor and Extension Urban Horticulturist
WSU Puyallup Research and Extension Center
2606 W. Pioneer
Puyallup, WA 98371
Phone: (253) 445-4542
"The Informed Gardener" webpage: Linda Chalker-Scott
"The Garden Professors" blog: http://www.gardenprofessors.com
I'm bummed I wasted her time, as it was apparently in her archive, but alas, there's no new contradictory studies, or she'd have mentioned 'em. The links she provided are pretty darned informative, and something every gardener can benefit from. The gardenprofessors are just that. A blog for/by horticulturalists. They evaluate products, test myths, analyze data...all that geeky stuff. Very informal and easy to read. And yes, the science does/can translate to indoors.
