Enriched Substrate of Fool's Gold?

I introduced today Hygrophilla polysperma (three cuts with three nots and four leaves each placed in all three buckets; all cuts are from the same stem so these are actually clones (I think so).

Being a fast growing plant I figure we should see some short term difference based on type of substrate (or not).



Pepetj
Santo Domingo

Week one completed. The plants in the buckets are still adapting there. No new growth observed yet. Almost total water change performed at 6:00PM with the same water I prepared last week.

Pepetj
Santo Domingo

Week number two completed. We do have some death from the Eleocharis parvula as well as new shoots from the Hygrophila polysperma in all of the three containers; let's see what happened in this second week.

Bucket #1, with inert gravel, produced new shoots in two of the H polysperma cuts; the one without new shoot experience rot at the base of the stem (I removed the rotten tissue as well as the two leaves next to it to replant). the Eleocharis parvula is almost certainly dead, it will surprise me if it's capable of surviving.

Bucket #2, with Eco-Complete produced new shoots in all of the stems of H polysperma, while the Eleocharis parvula shows fairly good adaptation so far.

Bucket #3, with "enriched" Eco-Complete produced new shoots in all of the stems of H polysperma while the E parvula shows somewhat poor adaptation.

I removed three stems, one from each bucket to compare root length growth (if any).

All stems develop roots with predictable outcomes:
Bucket #1 produced new root that measured up to 7mm in length.


Bucket #2 produced new root that measured up to 12mm in length


Bucket #3 produced new root that measured up to 24mm in length

A quick look at this data suggest that:
1) inert substrate barely induce root growth, which shouldn't surprise no one.
2) Eco-Complete produced better than inert substrate root growth, almost doubling it.
3) Enriched Eco-Complete produced the major length in new root growth, more than three times than the inert substrate and twice as much as the Eco-Complete.

It looks like Eco-Complete does provide some nutrients to the plants, at least within the first two weeks of use.

Plants do adapt to inert substrates but no idea how long they can make it. Rotten plant tissue happened only in the inert substrate.

Enriched Eco-Complete is the best of the three substrates as far as root development during the first two weeks of planting cuts of H polysperma.

Any observations, comments and questions are welcomed.

Pepetj
Santo Domingo

Let's see what keeps on going here... see you next week.

Hi Pepetj,

Thanks so much for doing this! I am convinced (anecdotally at least) that using an enriched substrate would result in 'better' or more vigorous growth.

I use black flourite and nothing else but EI and c02. The plants get excellent root structure and growth, but I feel that it would be 'better' with say ADA or even adding worm castings or such.

I am following this with interest!

Findings from week three are in line with previous ones. Mosquito larvae present in all three containers (not sure how to deal with this).

Let's see two pictures with the three sample specimens side by side. From left to right: Inert Substrate, Eco-Complete, Enriched Eco-Complete


Closer look:


Bucket#1, Inert Substrate, root growth: 1.3cm


Bucket #2, Eco-Complete, root growth: 3.0cm


Bucket #3, Enriched Eco-Complete, root growth: 4.9cm
(see picture #1)

As far as root growth, Eco-Complete (30mm) almost tripled the inert substrate (11mm) while Enriched Eco-Complete did 1.63 times better respect to Eco-Complete and 4 times more than inert substrate.

Water change done on Monday with same water source.

Let's see what happens next week!

Pepetj
Santo Domingo

Week Four: New variable emerges. Does Eco-Complete tie this up?

New secondary root shootings in the Hygrophila polysperma specimens are observed in most plants for the first time. However this seldom happens with specimens from inert substrate.

So far I've been using longitudinal growth of roots to infer nutrient richness of substrate. Findings since week 1 have been as expected: Inert substrate < Eco-Complete < Enriched Eco-Complete.

However this week a new variable (root networking?) becomes evident through observation. Following this criteria our findings change to this: Enriched Eco-Complete =? Eco-Complete > Inert substrate.

Bucket #1: Inert substrate (all three specimens planted in Bucket #1 shown in this pic). Note that only two roots per knot are present, placed at opposite sides of the knot. Longest root measured 2.0cm and this particular root was running along the substrate surface level; what difference does it make in inert substrate where the root shootings go? All other roots measured by me today ranged between 0.7 to 1.6cm. Barely one secondary root observed.


BBucket #2: Eco-Complete. The longest root measured 6.0cm that came from a knot closest to substrate surface level while it had roots at opposite sides in the deeper knot measuring 2.3 cm the longest one. One specimen had only one root measuring 2.6 cm from one side of the single knot buried in substrate. The other specimen had also only one knot buried with two roots, each measuring the same length of 2.4 cm.


Bucket #3. Enriched Eco-Complete: Plants had more roots forming what seems to be early stages of a network of root shootings coming from a single knot, even the knots closer to the substrate also have new root shootings (pic is a little bit out of focus)


A little rambling:
Remember the plant from Bucket #3 that had 4.9cm of root length at week 3? Unfortunately I broke this root while handling the plant today. I managed to measure the damaged root (ended cutting it) to 5.4cm so maybe it got hurt last week when replanted or slowed down its growth speed or something else I don't fully understand as a change in strategy due to developing more roots than there were previously in that knot. No way I can tell.

The specimen with the longest root (from Bucket #2, Eco-Complete) had secondary root shootings coming out of the main roots. I cut that part of the plant for ease of taking a pic as well as measuring.


All specimens from Eco-Complete and Enriched Eco-Complete have observable secondary roots. I have no means to measure wet or dry weight to compare plant growth but let's wait as time passes. At this point it looks like for the first 4 weeks Eco-Complete provides as much nutrients than Enriched Eco-Complete.

Hope the gurus come by and help us understand what's happening here. Maybe more time is needed to infer better.

Pepetj
Santo Domingo

Hi Pepetj,

Nice work so far and nice recording of results...

Of course more repetition would be nice but you are just going for some simple testing, no?

I think this is very interesting. I would have thought the enriched EC would have done 'best' in all terms of growth....

I would be interested to see the plants in perhaps 10-12 weeks and see side by side pics. I think the enriched EC would be tops, then EC alone, then inert.

Thanks for blogging!

A few things:

This does not include the factor such as adaptation time(2 weeks is not enough) and storage of resources within the plants themselves.
Generally, 2 weeks pre adaption is a good rule, then an 8 week grow out period.

Even this must be analyzed with caution.

When you also factor in the leaching of nutrients from the sediment into the water column, + the fact that aquatic plants will also take in nutrients from roots and the shoots, this will often skew some of the conclusions.
Overall, you are doing a comparison of adding ferts, vs not adding ferts in the sediment.

So is that better(adding ferts vs not) to growth?
Of course.

So this does not tell us much more than any one with a lick of common sense already knew anyways.
ADA tried to sell off their sediment in this same manner.

If the question is more specific(this is where things get much more interesting and the test become much more informative), say if :

"What is the difference in growth rates of shoots and roots between the top soil and worm casting with H polysperma, without water column influences".........then this is much more "interesting"
We are now comparing two different types of sediment treatments.

The inert sand etc......those are good and serve as a lowest end "control"
The rich non limiting fert is the upper end control.

Everything else should fall somewhere in between or at those ranges.
If not, then there's something wrong with your test set up.

The other issue is CO2 differences between samples and species of plants.
Most do hydroponic flask type test to get around that and grow them emergently, then there is no water column uptake.

I did some of these test back about 5 years ago with Ludwigia.