So, if you have Ca at about 80 ppm and Mg at about 20 ppm in a fertigation solution at a buffered pH of 5.8, you have enough of those ions available for most orchids, including kovachii? In that situation is top dressing with dolomite (or crushed oyster shells) adding anything?
I would really need help with my fertilizer mix!
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Question was directed not to me, but if I can, i say, no.....dolomite dressing is just for compensation any mistake of our setting, if solution is a little acidic, than 5,8.
photo from said paper--growing in moss on stone
I think you are probably right. The higher the pH, the more bound to other things Ca, Mg, and P become, reducing the available ions. It doesn't make sense to try and feed kovachii at a pH of 8.0. Although I have purchased dolomite and crushed oyster shell, I am thinking I will not use.
With regards to kovachii ask this question...." Is anyone having great results growing kovachii without the addition of some form of limestone or shells to the substrate and or top dressing of a calcium supplement".
Will be interesting to see what Roths says, but I think he has not been doing this with kovachii because he focuses on getting the pH correct with fertilizer with good amounts of nutrients, including Ca and Mg.
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Indeed, well I use Dolokal on top of the potting mix quite frequently, but that's to correct the pH, as I use an urea/ammonium based fertilizer....
For the ratio, I never would go over 30ppm calcium and about 10-15ppm magnesium at the roots for constant feed. Potassium is way more important, in the 100+ppm
Dolomite is a mixture of calcium and magnesium carbonate. I think I am understanding you to say that you put a layer on top to mostly to provide the carbonates for buffering of the acid fertilizer OR do you think it is also providing necessary additional Ca and Mg?
About calcium and water solubility etc as previously… in glacial historical settings the ground water moves through crushed glacial till, which definitely releases into the groundwater and affects the soil it’s in, and where the streams come out.
Now that’s not anything like solid limestone non crushed or mixed into the substrate which likely would have much less release if not very little
Now that’s not anything like solid limestone non crushed or mixed into the substrate which likely would have much less release if not very little
Calcium carbonates need to be dissolved first by whatever acid that will be in contact to it to form the aquatious form calcium bicarbonate. Both are now in ionic forms where the bicarbonate can increase the pH and the CA ion is now free to be absorbed. So if this calcium bicarbonate happens to be next to the roots then yes, it can ba taken.
I have even read that bicarbonate as ion is also absorbed by plants. It's not used by the plants per se, but it can be used for ion exchanges, could either be for pH balancing or charge balancing.
I have even read that bicarbonate as ion is also absorbed by plants. It's not used by the plants per se, but it can be used for ion exchanges, could either be for pH balancing or charge balancing.
So, if you chronically have a substantially acidic pot medium (most likely this is an organic medium) and you want to counter this long term, dolomite could be top dressed (or mixed in) to gradually release buffer that would bring the pH up. It is not a very effective way to increase Ca or Mg for root uptake.
Yeah, it's not effective and may not be enough. When one is using a certain mixed fertilizer, like 20 20 20 or 20 15 16, you will notice that Ca, MG and S are not provided if ever not in adequate quantity. This is because one is expected to use tap water that has them in acceptable amount. So it is important to know what's in your tap water. If the calcium bicarbonate is too high, then make a mix with RO or distilled or better yet, rain water to lower the cal bicarbonate as to how much you need to counter the effect of your fertilizer solution. The more fert you mix, the more tap water you will add back for buffer. Actually the more buffer you have the lesser the fluctuation of the pH. To know how much calcium you have in your cal bicarb buffer, in a pure cal bicarb, Ca is more or less 40%. You may need pH down and or pH up to hit your final desired pH. This tap water is to buffer the fert solution. The addition of lime or dolomite is mainly to buffer the pH fluctuation of your media.
1) Should it be considered the same as malic acid /acetic acid /lactic acid/other TCA inter. in term of bacterial rot promotion?
If it is living moss promotive rather the dead one, it’s likely some organics consistently produced and excreted to make the trick… if any
2) Should I bother with alkalization from urea hydrolysis? Would Ca and P precipitate out?
3) Question on molybdate……is its natural abundance co-related with karst/shale with ocean origin? Does CaMoO4 get pretty low solubility?
4)
“Stoichiometry of carbon, nitrogen and phosphorus is closely linked to trophic modes in orchids”
Should it be considered any strong phosphorus-demand in paph.? The %P value shown in “Multipart thread, mineral nutrition…” seems relatively higher compare with
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