Effects of Synthetic & Organic Fertilizers on Soil and Plants

[Mr. Terpz]

So I came across an article (http://www.gardenmyths.com/does-fertilizer-kill-soil-bacteria/) which basically claims that synthetic fertilizers "do not harm or kill soil microbes." However, the article contradicts itself when it states:

"It is true that fertilizers are salts. [...] ...salt is a compound made up of two or more ions. [...] Salt will harm bacteria and plant roots if there is direct contact. Due to the large number of microbes in soil, and the small surface area of the fertilizer crystals, this has no significant effect on the microbe populations in soil. Once the salt is dissolved, the ions quickly become diluted as the water moves through the soil layer. Diluted ions in water do not harm microbes or plant roots. In fact both of their lives depend on the ions being in the water. It is the ions that they absorb – not the salts."

So, how do synthetic fertilizers affect soil microbes? I know there are many different kinds of synthetic nutrients with differing chemical compositions, but is there something they all have in common? I am already aware that synthetic fertilizers can harm the environment. But I want to know how they harm plants.

From my experience, properly cultivated soil grown cannabis always tastes better than properly cultivated soilless grown cannabis, and this raises one more question... is there some kind of special symbiosis between plants and organic matter that accounts for improved flavor and aroma? Are the microbes doing something else for the plant, other than just making nutrients available? After all, nutrients are simply base elements that occur in different sources, and on a molecular level they are the same to the plant, whether organic or synthetic. So then, what else is at play here?

When applied in proper proportions, nutrients cannot be held accountable for any detrimental effects. What else comes with synthetic fertilizers that we need to avoid? Is it something radioactive? I feel like i'm missing a very important piece of the puzzle here.

Somebody enlighten me.

 

[IIIShadesOfBlck]

Organic grown plants have a higher brix measure, sugar content.

Plants with higher brix have a higher resistance to pests, fungus and disease.

Have you ever eaten a piece of organic fruit and noticed it is much sweeter and better tasting than a non organic counterpart? This is brix.

Pests are drawn to plants with lower brix because the cell walls are softer and easy to penetrate.

I'm not going to go thru it all but that's the start of it.

 

[n_d_ledz]

Is there a symbiotic effect? Would you ever consider Molasses to be a "fertilizer"? When you consider it feeds the micro life which reproduce better and produce usable bits of nutrition for the plants...yes. Organics feeds the soil, chems feed the plant.

 

[Douglas.Curtis]

Organic grown plants have a higher brix measure, sugar content.

Properly grown plants have higher brix, not necessarily organic.

Plants with higher brix have a higher resistance to pests, fungus and disease.

This is definitely true. Plants given the full complement of elements have a higher brix and also produce proteins. This is 'more common' with organics, yet not exclusive to them.

Have you ever eaten a piece of organic fruit and noticed it is much sweeter and better tasting than a non organic counterpart? This is brix.

This has been debunked, as there is no tie directly to organics for it.
The higher brix fruit will taste sweeter, yes indeed. Simply being organic does not produce a higher brix and non-organics are often sweeter. Blind taste tests agree.

Pests are drawn to plants with lower brix because the cell walls are softer and easy to penetrate.

Well, they're actually drawn to them because their color (to the insects) is different than higher brix plants.

A lot of things have been attributed to "Organics" when it's more a matter of incomplete nutrition with most refined-salt based products. Still a lot of work to do on the average hydro store product.

 

[Mr. Terpz]

Good point. So you are saying the basic underlying difference between organic and non-organic cannabis is the brix measure, or sugar content. But... can't a high brix measure be achieved with synthetics? Is that all that is at play here, or are we forgetting other important variables? I'm no chemist (or botanist) but i would love an educated explanation. I feel like we might be getting somewhere here.

 

[Mr. Terpz]

so when it comes down to the comparison between soil and soilless grown cannabis, the difference is primarily in the flavor and aroma. This leads us to terpenes. Assuming that adequate nutrient availability exists in both substrates or mediums, other processes must be responsible for increased terpene content, both quantitatively and qualitatively. Cannabis grown in soil organic matter tends to result in better flavor and aroma 90% of the time. Plant Growth Regulators (PGRs) have been shown to correspond to terpene production. Are there more PGRs naturally occurring in soil compared to soilless mediums? How does one maximize terpene content?

We already know that sulfur and potassium play a role in terpene production, and we already know that low humidity, increased UV-B, and lower temps can promote terpene production.
But focusing solely on the soil aspect, is there something in soil that directly improves or contributes to terpene production, other than the nutrients?

 

[Mr. Terpz]

I feel like I am answering my own questions here. I've been researching the relationship between soil microbiology and plant development. I came across some interesting articles. Here's what i found:

Nitrogen favors terpenoid production.

Phosphorus deprivation increases terpene emission in response to heat stress.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474957/

Evidence has accumulated indicating that classic plant signals such as auxins and cytokinins can be produced by microorganisms to efficiently colonize the root and modulate root system architecture. Other classes of signals used by bacteria for cell-to-cell communication can be perceived by plants to modulate gene expression, metabolism and growth. Also, volatile organic compounds released by certain plant growth-promoting rhizobacteria play a role in plant immunity and developmental processes.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2801380/

The second source here may finally explain the "magical mystery" of growing in organic soil for superior quality, since microorganisms do not thrive in soilless mediums.

 

[Mr. Terpz]

It seems like I am having this conversation with myself. But for the sake of sharing valuable information, I found something else that may be of interest to terpene-craving connoisseurs.

According to the second source I listed previously, plants are able to recognize microbe-derived compounds and adjust their defense and growth responses according to the type of microorganism encountered. This means that a greater diversity of microbes in the soil can result in a greater complexity of terpene expression, among other genetic traits.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2801380/

For example, many growers have claimed that Bat Guano contributes to some of the best flavors in soil grown cannabis. Aside from its obvious nutrient content, there could be some very special kinds of microorganisms naturally occurring in the guano, microbes which could possibly have a strong influence on terpenoid synthesis.

Does anyone have any input on this?

 

[Phaeton]

Sometimes I consider myself a long time commercial gardener, then a person with experience posts and I feel silly with some of my naive opinions. First plant was in 1983. Quit my day job in 2011. I did like the security of wages.

But to the subject. Full sythetic garden. GroDan rockwool croutons (1 cm cubes) for media, General Hydroponics Three part combo and Nutri-plus Pure Gold (28% Fulvic acid) for nutrients.
This grows strong healthy marijuana plants. Bland high potency buds good for extracts or maintenance smoking. Taste and smell are not there.
Individual chemicals were added without changing much. Bat guano was used, first without success, fruit bats' guano, high in nitrogen, had little effect. Insect eating bat guano, high in phosphorus, caused major odor increase in the bud room and much carried over to the dried buds.
Phosphorus alone had been tried without results. I am assuming a combo of trace chemical combinations activate genetics on a scale we cannot directly identify.
Forigen, the chemical responsible for flowering, has never been isolated or directly observed. I expect the identities of some gene expression molecules will be just as elusive.

The bat tea took three days to prepare and was a messy time consuming process that, while improving aroma and taste, did not increase potency at all.
I gave it up after just over a year.

 

[mojave green]

Here we go again!

 

[Douglas.Curtis]

so when it comes down to the comparison between soil and soilless grown cannabis, the difference is primarily in the flavor and aroma.

Yes.

In my experience, properly done hydro blows organic out of the water. In other's experience, they all say organic. Those who try my best results from hydro... all agree it's the tastiest, most aromatic and amazing organic they've ever had.

I'm sure there are those who grow the same quality or better using organics, I simply haven't run across them personally.

 

[DocTim420]

Properly done hydro (synthetic) and properly done "soil" (organic)--are both great! It is the "gardener" not the "garden" that makes one great.

That said, there are certain things I pull out of my plants (custom peat based grow medium here) that my buddy (who is DWC hydro) is unable to. We both grow for the same dispensary and grow some of the same strains...but the dispensary markets them differently, since there more differences than similarities between our two products.

His results are good but different--but when it comes to plant growth, imo--plants grown in hydro systems will always outpace those in "soil". It takes about 6 weeks for my plants to achieve height and size of what he gets in 4 weeks. As for resin and "sweetness"--I seem to win hands down (different lighting systems), but when it comes to the terpene profile and potency numbers--we both are there (at least that is what the tests from the lab say).

Of course he is unable to operate a perpetual operation (I harvest every week or so) and when he experiences equipment failure (like a dead pump last week)--disaster is almost certain (dry roots--lost a whole room), whereas soil grow mediums are more "forgiving" and are less dependent on "technology".

 

[Douglas.Curtis]

Properly done hydro (synthetic) and properly done "soil" (organic)--are both great! It is the "gardener" not the "garden" that makes one great.

Couldn't agree more.

 

[Phaeton]

Nutrient profiles are the same as spectrum profiles. Today's anecdote is about the three of us supplying to one of the same retailers. Nate I have mentioned before, Egarden doesn't want his name used.
We have very similar wattages. Egarden mixes his lights, HPS, MH, and T5 but does not care for nutrients from vats in a factory. Nate has a witch's brew of supplements under HPS and blue LED on a pair of light rails.
We all get along fine, Nate outproduces us all, I come in stongest, and Egarden is where we go for exactly what we are looking for.

mohave green says "here we go again" and I never understood that. Formerly I was in warehousing, Egarden was transportation, Nate did construction.
Do we fight and argue over our varied past work experience? Do we fight and argue over our present work experience? I suspect Nate of being republican, he suspects I am Buddhist, Egarden lives alone.

Attitudes on mental health get to me at times, I was an autistic (Idiot) savant when younger, age is the great equalizer. Get old enough and the big picture is all there is left to see.