The concentrations of most essential micronutrients are presented in Figure 3. Again the micronutrient concentrations in the coir are approximately twice that common in sphagnum with the finer grades tending to have higher concentrations. The iron concentrations are depicted in Figure 4. The concentrations of iron were approximately equal to that commonly found in sphagnum. Again the coarser fibers showed a lower concentration of iron than the finer grades of Mexican AgroCoir suggesting a greater concentration of the micronutrients in the finer pith than in the coarser fibers.
The Saturated Media Analysis (SME) provides an estimate of the nutrients that are readily available to plant roots. It provides a measure of the soluble nutrients in a substrate. These measurements help to quantify the nutrients that can be readily absorbed by plant roots. In Figure 5. we see the pH levels for the different grades of coir compared to sphagnum peat. All grades of coir showed pH levels between 5.6 and 6.0 while sphagnum was about 3.2. All grades of coir showed approximately the same pH. The coarse, more fibrous grade demonstrated a slightly lower value at 5.7. The near optimal pH values in coir likely arise from the comparatively high levels of potassium in the coir.
The total soluble salts levels, as measured by the electrical conductivity (E.C.), range from adequate to high in all grades of coir. Those values are depicted in Figure 6. Again the coarse more fiberous coir has a lower quantity of total soluable salts than the finer materials. Sphagnum is much lower in soluable nutrients, especially potassium, (Figure 7).
My growing partner Steve Doonan uses coir almost exclusively for his flytraps now. It is a great medium with several properties that make it superior to peat in my opinion. His plants thrive in it.
The only reason I don't use it is because coir is usually processed with salt water due to the fact that most coconut processing plants are on islands and salt water is free and easily accessible. So coir is extremely high in dissolved solids (mostly salt) and must be soaked in rain water or reverse osmosis water 8 to 10 times for 12 hour periods to bring down the TDS measurement to a usable level for CPs. I don't want to take the time and use all the water to do that.
The elevated pH levels don't seem to bother the flytraps at all. And coir is much "airier" and more resistant to breaking down than sphagnum peat moss.
http://www.agrococo.com/Bethke/NUTRIENT_ANALYSIS_OF_AGROCOIR.pdf
If it was me, I wouldn't use coir with Dionaea unless boosting the acidity with something like pine needles or pine bark mulch - and only if the media gets changed annually. They like higher acidity than most other genus of carnivorous plants. I find they do better in pure peat moss or at least 75% peat moss.
I'm on exactly the same page as you BigBella. The move to coir was mostly environmentally based but, as you say, there is no free lunch. A lot of time and water is wasted in the process of making coir usable.The astronomical salinity was also an issue when a few friends began using coir, both for Dionaea and Nepenthes. They spent a great deal of time -- as you have already described -- rinsing and re-rinsing the material; time that I do not have to spare. That said, I have never been impressed with the results; and yours -- honestly -- are the first positive ones that I have heard; but I know full well that you know what you're doing.
Also, the move to coir over peat-based composts was over environmental issues -- primarily, the preservation of diminishing bog-lands; and coir was simply a byproduct of existing coconut production. That growers would have to go to such Rube Goldberg lengths and the repeated use of RO water (wasteful in and of itself in its very production -- four or more gallons of "waste" water to produce one) to make coir feasible, defeats that purpose, in my mind. I guess there's no free lunch where that's involved.
Since I re-pot my flytraps annually, any breakdown of sphagnum peat hasn't posed an issue -- and all of my old compost has done wonders for the tomatoes and eggplants . . .
The soil you use for your plants also makes a difference. Peat is very acidic and normal plants grown in pure peat or a peat/sand mix have trouble absorbing nutrients or otherwise do not do well. Coir is a neutral medium and should make nutrients more available to the plants. It is used successfully with Nepenthes so I tried it with Sarracenia.
http://www.carnivorousplants.org/howto/Feeding/Images/SarFert2.jpg
Soil experiment comparing peat and coir, with and without Osmocote™ 17-7-12 pellets. As you can see Sarracenia responded much better to peat soil than coir.
The Sarracenia plants did not like coir as well as peat.
The photo below shows the results after 14 months of a comparison of a traditional sphagnum peat moss based medium with a coir (coconut husk pith) medium. -Steve
-------Fire is common in all Dionaea areas, and as a
result the ground vegetation is sparse, and the soil
often has a "pepper and salt" appearance due to
the incorporation of charred and decaying organic
material into the white sand. Sometimes there is a
shallow layer of peaty material above the inorganic
soil. There are no species which are always in association
with Dionaea but instead a mixture of
savannah and bog types with wide moisture tolerances
(e.,. Ilex, Zenobia, Lyonia, Polygala, Liatris, Aristi-
da). Not all of these occur in every location and
in different places the proportions vary. However,
there are three other insectivorous genera (Pinguicula,
Sarracenia, and Drosera) which nearly always
occur with flytraps in varying abundance. The land
where Dionaea grows is generally completely flat or
with less than a 3% slope; where this slope is present,
as is usual around a pocosin, populations have quite
well defined boundaries: a dense shrub zone at the
lower side marks one limit while the other is apparently
determined by the summer depth of the water
table. Over wide flat areas especially in several of
the southeastern counties, Dionaea is distributed
throughout large tracts of land which have not been
disturbed. It rarely grows in depressions where water
is likely to collect, but on the edges of such positions,
a fact also noted by Dean (1892). Such hollows
which have filled with Sphagnum, sometimes support
Dionaea but these are not typical habitats. In the
usual site the surface of the ground is generally damp,
except that at the upper limit of a population zone it
may become completely desiccated to a depth of
several inches during the driest part of the year. The
sand in these positions may be almost snow white at
the surface due to the lack of organic matter and
pluvial action.
The Klej-Leon and closely related soil series
occurring primarily in regions of smooth relief, are
the chief soils occurring in that region of the coastal
plain where Dionaea is found. The chief soil forming
the Dionaea substrate belongs to the St. Johns series,
a ground water podzol (Lee 1955), as was observed
in practically all borings taken at Dionaea sites. The
soil profile descriptions for these sites were all very
similar; most have a thin layer of peaty material at
the surface, with a dark gray or black surface horizon,
gradually lightening in colour with depth, overlying a
coffee-brown cemented laver-the hardpan. Beneath
this, the color varies somewhat from brownish-gray
to almost yellow. Occasionally excessive wetness of
the strata below 10 in. made it impossible to bring
samples to the surface and prevented positive identification
of the soil type. Otherwise all soil borings
were regularly taken to a depth of at least 30 in.
------PHYSICAL AND CHEMICAL ANALYSES
The profile of a 5 ft deep soil pit dug at Location
2 showed the characteristic development of the St.
Johns series (hardpan soil), with a dark-coloured
surface horizon gradually becoming lighter with depth
and overlying, in this case, a yellow-brown sand.
Plant roots were almost entirely confined to the top
3 in. with the few scattered in the next 10 in. mainly
belonging to the various shrub species.
The physical properties were determined using
samples from this pit and indicate the typical development
of a ground water podzol in this region. In
the hydrometer separation of sands, the total sands
averaged between 93% and 98% at all depths and
the total colloid content was no greater than 1.5%
to 2.5%. Over 26% of the sand was retained in the
60 mesh sieve while another 50-60% was retained by
the 140 mesh sieve. The moisture and xylene equivalents
for the top 3.5 in. were 6.07% and 3.60%
respectively.
Chemical analyses of the coastal plain soils indicate
a verv low level of fertility. This was shown by
analyses of surface strata (top 4 in.) fromn the two
Locations at Beaufort and fromt samplings near
Edgeconmbe and White Lake. The analyses were made
at North Carolina State College by Mr. Robert
Schramm, using standard colorimetric methods. Although
the samples were taken from widely separated
areas, they were markedly similar in chemical composition.
The most noticeable characteristics of these
soils are the high acidity (pH 3.5-4.9), the complete
lack of detectable calcium, manganese and nitrate,
the very low amounts of ammonia (2 ppm), iron (1
ppm), magnesium (1 ppm), and phosphate (less than
2 ppm). The concentration of potassium at Locations
1 and 2 was 2 ppm which is equivalent to an agricultural
rating of "medium."
-------An interesting confirmation of these transplant
experiments was gained when a visit was payed in
January 1957 to Mr. Aubrey Shaw of Lake Creek
Community, Bladen County, who had transplanted
Dionaea into several locations showing obvious physical
differences from the natural habitat. The transplants
were made in 1950 as follows:
1. Dry area
2. Heavily shaded area
3. Moist area
4. Shallow drainage trough (high pH)
5. Submerged in a pond.
----
4. The shallow drainage trough, which originated
in a cultivated field, was always wet but seldom
carried a large volume of water. Th soil was less
acid (pH 5.5) than is normal (pH 3.8-4.5) in Dionaea
habitats. The plants here were large and the leaves green,
but the glands showed a slight red coloration. The leaves were
more typical of the spring than the winter type, with long,
winged petioles and medium-sized traps. The plants had
flowered in 1956, and the seedlings were larger and relatively
more abundant than in area 3. It was reported that the
"catch rate" of these plants was relatively high, and many of
the traps investigated showed the remains of partially digested
beetles, woodlice and planarians.
----------Soil Texture
In the first experiment, 12 large, vigorous plants
were transplanted into flats containing the following
soils:
Flat 1. Natural coastal plain soil
Flat 2. A local clay-loam garden soil
Flat 3. A specially prepared greenhouse potting
soil
Flat 4. Washed white sand
Flat 5. Pure peat moss
Flat 1. Natural coastal plain soil: All plants
bloomed within 49 days of their initiation,
although 2 plants did not reach maturity
owing to accidents with flowering shoots.
After flowering, all plants developed
normal summer-type leaves with the characteristic
red coloration.
Flat 2. Local clay-loam garden soil: Flowers of
4 plants finally reached maturity within
46 days of floral initiation. Thereafter,
the plants showed little vigor, the leaves
remained very leathery and of the late
winter type. In general, the leaves did
not develop traps.
Flat 3. Greenhouse potting soil: One plant
flowered within 44 days and died shortly
thereafter. All other plants died within
7-0 days of the time of transplanting.
Flat 4. Washed white sand: All initiations reached
maturity within 47 days. After flowering,
Vigorous growth occurred with the production
of summer leaves and red coloration.
Flat 5. Pure peat moss: All initiations reached
maturity within 48 days. After flowering,
tie plants remained in typical spring growth
condition, with broad petioles and small traps.
When the experiment was finally concluded after
5 months, all plants in Flats 1, 4 and 5 were alive
and very vigorous although the plants in Flat 4
were much larger than those of the other two. In
Flat 2 only two plants were still alive, and were
very unthrifty. These were taken from the soil and
the roots washed. The probable cause of their low
vitality was immediately apparent-there had apparently
been no new root growth during the whole
time of the experiment. Each plant had 4 roots
and not one was more than 4 cm long. In contrast,
plants removed from the other flats, each had 6-8 well
developed roots which averaged 3-5 cm in length
(in Flats 1 and 4), and 15-20 cm in length (in Flat 5).
This experiment indicates that soil differences do
influence the rate and type of development of
Dionaea. At first, the sudden rise in temperature
from the field to the 72F greenhouse was probably
responsible for the speed of appearance of the initials
without any affects from the soil itself. However,
after a time, the health and vigor of the plants reflected
the soil type, with a decline in those plants
in pure mineral soil (possibly the speed of decline in
Flat 3 was partially due to the fertilizer added in
the preparation of that soil), which led to coloration
changes, loss of initials, loss of fertility, and
finally, death. The explanation appears to lie in the
fact that root growth is suppressed in the heavier
soils. The higher pH and nutrient content of the
artificial soils are probably contributory.
A second experiment involved the use of different
proportions of sand and clay as the substratum for
Dionaea. Transplants were made in September. 1956,
and carried through to January, 1957. Mixtures of
clay (Georgeville, a kaolinite type) (100%, 75%,
50%, 25%, 0% by volume) and sand were made and
duplicate flats of each mixture prepared. Thirty
mature Dionaea were planted in each flat as well as
ten 2 to 3-yr-old plants.
Results of this experiment were unexpected, as
the plants in the lower proportions of clay were as
slow in growth as those in the higher, and generally
died off more quickly. Georgeville clay has been
shown to contain a high percentage of mineral nutrients,
which may be the reason that all plants did
poorly. The young plants all died within a month of
planting, while plants in the flats with 25% and 50%
clay had all died within 2 months. At the end of
the experiment, only 10 plants were alive in the
100% flat, and 15 in the 75% flats. The plants in
the sand flats all grew normally.
-----NUTRIENT EXPERIMENTS
Nutrient solutions (modified fronm Burkholder &
-Nickell 1949) and a dilute Hoaglands solution were
the main mineral solutions used, and a yeast protein
extract a-nd Drosophila melanagaster were the sources
of organic nutrient. The mineral solutions were
supplied through the soil and through the leaves, and
the organic material through the leaves only. Plants
were grown in washed sand. The seedlings were
germinated in the laboratory and the older plants
were obtained in the field.
Details of the exploratory experiments would not
be justified in view of the inconclusive results. The
generalizations suggested by the work indicate that
intensive study along these lines would yield rewarding
information. All plants receiving mineral nutrients
grew poorly, while all the controls (watered
with distilled water) showed much more satisfactory
growth. The mature experimental plants steadily
declined in weight, and (died after about 3 months.
Growth of all plants whether experimental, control,
or in normal soils of the coastal region, was very
slow, and this fact prevented further experimental
work in the time available. The plants which were
"fed" organic material, on the other hand, showed
more vigorous vegetative growth. None of the plants
under the various nutritional regimes flowered in the
season following the experiments, while approximately
the same proportion (45%) of the control plants
flowered as was noted in the field (40%). It is
probable that poor growth of the experimental plants
resulted from using too high a concentration or the
wrong proportions of nutrients.
St. Johns' series soils have a high water table and
an organic hardpan which is usually not more than
24 in. below the soil surface in Dionaea areas. The
soil is acid with a pH range of 3.9-4.5. Although
Dionaea will survive in less acid soils, growth above
pH 6.5 is poor.
Why not do a study with much more controlled conditions and submit a paper to the Carnivorous Plant Newsletter?