True or false? Substrate that is too rich hinders plant growth

[bossteck]

Read in a book (sorry forgot title) recently that if substrate in a tank is too rich, root growth of plants would be extensive, but leave growth would be hindered.

Would like to hear from everyone based on your experience / research.

[Shadow]

you might want to specify which substrate considered too rich.

[bossteck]

Honestly, I don't know. It was something I came across while browsing an aquarium related book. Want to verify it here, so asking if anyone had experienced extensive root growth but minimal plant (stem / leaves) development for their plants.

[ervinelin]

Honestly, I don't know. It was something I came across while browsing an aquarium related book. Want to verify it here, so asking if anyone had experienced extensive root growth but minimal plant (stem / leaves) development for their plants.

I doubt this is true. If you read up about hydro and aeroponics, the key to good growth top side is healthy roots. And hydroponics and aeroponics have nutrient rich solutions around their roots all the time.

I think the problem might arise if the concentration of nutrients is so high that it becomes toxic to the roots. This issue of toxicity I've read, but I doubt any regular substrate will reach these toxic levels.

[Fuzzy]

Yeah if the substrate is "too rich" to the point of hindering plant growth, the roots of the plant won't grow well,
and you will start seeing signs of fertilizer burn in your plants.

This isn't something that is naturally occuring in any off the shelf substrate mix. More of a mistake in dosing dry ferts.

I doubt you can even reach this level of overdosing with liquid fertilizers unless it seems normal for you to be pouring 1 or 2 full bottles of
liquid ferts into your tank at once, heh.

[rav]

Yeah if the substrate is "too rich" to the point of hindering plant growth, the roots of the plant won't grow well,
and you will start seeing signs of fertilizer burn in your plants.

This isn't something that is naturally occuring in any off the shelf substrate mix. More of a mistake in dosing dry ferts.

I doubt you can even reach this level of overdosing with liquid fertilizers unless it seems normal for you to be pouring 1 or 2 full bottles of
liquid ferts into your tank at once, heh.

Yes agreed. Too much of anything is not good. Fertilizer burn do occur to plants. Not to mention the outbreak of algae where there are way too much fert.

[barmby]

Yes, I try pouring LushGRO Aqua to my mother's "qi gu" during Chinese New Year. The next few days, the leaves turn yellow, brown and black at later stage. However, if I don't touch it, just water change every day, the plant will blossom. Strange huh? Less is more

P.S : QI GU is a type of Echinodorus which some older generation grow during CNY.

[GaspingGurami]

Colin, if I'm not mistaken, the chinese new year arrowhead plant is a Saggitaria and not Echinodorus. I much prefer to eat the rhizome fried like potato chips.

[barmby]

Yes, the arrowhead plant! yes, the rhizome can be fried like potato chips

[blue33]

I believe the substrate and liquid ferts is of different ratio nutrient. And substrate may not release all the nutrients out at one go, but if is liquid then it is different thing, that will have direct impact on it, more like burning sensation, plants tends to die after that especially those just water only like Barmby mention, but if u drop 1 small little drop you would have different result. Most substrate release nutrient at a period of time, they dont release just like that, some substrate absorb nutrients and release also.

I believe everyone knows that ADA1 has the most nutrients bind on the substrate, most people get algae if is not control well but i get good roots and leaf grow. I think they are one of the best substrate in the market to grow plant.

[bossteck]

Ok, I managed to dig out the book.

The book is "The complete encyclopedia of tropical fish" by Esther Verhoef-verhallen.
So, this is not your how-to-set up a planted tank book, but that's where I got the passage below.

The nutrient base should not be placed right on the bottom, but on top of a layer of gravel. Do not use too much nutrient base: a 2cm layer is usually more than enough. If you use more the plants will get too much food, which results in excessive root growth. The plant itself does not grow as much, which defeats the objective.

I don't think we're talking about commercially developed soil like Gex or ADA here, rather, the old base fert and gravel method.

Anyone have experience that can collaborate what was written?

[blue33]

If you look at my signature icon, on the left tank, those are using red Gex soil on top and below is >2 inches of JBL base ferts, that was when i just started planting hobby, you can see the amazing growth on the super rich gravel with lots of nutrients. Btw the tank is only 1.5 ft cube tank.

[Blue Whale]

Nope! I disagree.

I think Leaf will be bigger and more than the roots ^o^Y Hee Hee. Therefore, if leaves are reduced, the stress on the roots absorption rate would be lesser. Hence even for soil planted pots plants, we also constantly look out for overgrowth leave and trim them. During trimming stage, no one is to disturb the timmer, if not, cut wrongly you might regret it...very...very....very....very much! Observation based on the old fert base layer method, then thick sand.

My Mom always steal my tank water to water her plants nowadays. So my tank always not enough water -.-"

[mozaqua]

Not sure what the question is asking here. Substrate being rich: to me means that it is high in nutrients such as Nitrate, Ammonia and Phosphate.

So, True, it will hinder growth in plants, by killing them. Same with house plants, you add too much fertilizer they will die!

Now if your talking about other nutrients, they are probably not a problem. Those commercial substrates (ADA, GEX, Seachem, etc.) don't have much if any Nitrate, Ammonia or Phosphate.

[Plantbrain]

As mentioned by several folks, what specifically is rich?

Organic matter?

Then yes, a nice range of 0.5% to about 5% is good, more than 10% is bad.
At least based on natural systems and soils.

Hydroponic solutions are sprayed directly on leaves of aquatic plants, called fertigation, this is also done for most ornamental production in the USA.

These typically are about 210 ppm of NO3, 60ppm or so of PO4, 235ppm for K+, and they go directly on the leaves as well as roots.

This is how most aquatic nurseries in the USA, Australia, Denmark grow their aquatic plants.

So it takes more than these ranges to "burn". As far a sediments, they can be extremely high in most nutrients, and often are. % organic matter, other factors that affect the health of the plant, thus the roots, also play huge roles.

I think the author was worried about aquarist thinking more is better like is the case for light, but not for nutrients.

Regards,
Tom Barr

[Fuzzy]

Hey Tom! Thanks for the input in this thread, I was just curious if you've ever experienced this yourself, the substrate for an aquatic plant being too rich to the point that the plant has such vigorous root growth that it stunts the growth of the rest of the plant?

This is some sort of in-between stage between nutrient deficiency and fertilizer burn that I've not heard of before prior to this thread.

Oh! and I'm looking forward to your ADA Nutrient Analysis report too!

[Plantbrain]

I think it might be a deficiency if anything, I've never seen anyone ever burn aquatic plants underwater with fertilizer to date.

The only nutrient that will really mess the plants up is NH4 perhaps, but it has to be lethal for fish before it even starts to get even remotely close.

It's most often a CO2 issue.
Not nutrients that cause stunted tips or progressively small and smaller tips.
That's much more likely to be CO2.

Hydroponics is a very rich compared to what aquarist add, about an order of magnitude or more You are not going to burn or harm aquatic plants until you get to the salt salinity stress levels. If you run out, well then they will grow slower and then finally you'll get issues.

Reducing light will make both CO2 and nutrient stress levels go down.
So I'd do that and tweak CO2.

That will yield much more fruit than messign too much with nutrients, add them consistently and make sure you do not run out, it's not likely you will/could burn them. Fish would die first.

Regards,
Tom Barr

[Blue Whale]

I don't think it's reference to hydroponics. Got gravel layer reference.

Hydroponics roots may be submerge into nutrients water or sprayed as Tom have posted.

[Plantbrain]

Read in a book (sorry forgot title) recently that if substrate in a tank is too rich, root growth of plants would be extensive, but leave growth would be hindered.

No, this is not correct.
If you have limiting nutrients in both locations, you will get higher Root to Shoot ratios. Lots of roots, few leaves. This has been shown many times over long time frames in many studies.

"Rich" sediments can mean many things.
Rich in what?

If you have non limiting nutrients, then you get a much more even root/shoot ratio, perhaps even less.

The roots do not have to work hard to get all the nutrients required. So they do not allocate as much resources to the root growth, they allocate more to leaf /shoot growth instead. This same idea is true with terrestrial plants and fertigation.

If the water column is also rich, you may even cut the roots off.........and still maintain the same leave stem growth rates:

http://cat.inist.fr/?aModele=afficheN&cpsidt=13882784

If you can pull up the full article, it's a very good paper on resource allocation.


So in such cases, the sediment fertility has little significant impact.
I still do not know what is meant by too rich?
The only thing I can think of is too much organic matter, too much material that will rapidly deplete the O2 levels in the water as bacteria break it down etc.

I suppose too much Zn, Cu etc, NH4 would have to be insanely high to cause an issue.



Regards,
Tom Barr