Cal mag + lemon juice

Does this help the roots uptake calcium & magnesium nitrate?

Not to the best of my knowledge. Lemon juice is typically used to "naturally" adjust PH.

I think it chelates the calcium I'm not sure

Lemon juice lowers the pH of the solution. Calcium becomes less available to the plant as the pH goes lower.

I doubt calcium needs to be chelated to be absorbed.

Ok, dammit lol..

troy said:

Ok, dammit lol..

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BUT... The lemon juice probably helps some other nutrients become more available and that may affect the calcium or magnesium uptake indirectly.

troy said:

Ok, dammit lol..

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May not be so bad. Uptake of nitrate increases pH, a lil help from lemon will bring the pH back to optimal.

I believe that the citric acid will combine with some (a small amount) of the Ca to form insoluble Calcium citrate thereby making less Ca available to the plant. (not that that's a big issue and in fact probably a good thing)

Lol.. even worse, calcium binds to citric acid aarrgghhh, will never do that agian, cal mag is expensive

Stone said:

I believe that the citric acid will combine with some (a small amount) of the Ca to form insoluble Calcium citrate thereby making less Ca available to the plant. (not that that's a big issue and in fact probably a good thing)

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That is true in concentrated solutions; on the ppm level calcium citrate is soluble (0.85g/l at 18C).

Bjorn said:

That is true in concentrated solutions; on the ppm level calcium citrate is soluble (0.85g/l at 18C).

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Yes, good point ... also citrate and malate together form a complex with Ca that is more soluble than either citrate or malate alone.

Citrate also helps to maintain phosphate availability when Ca and Mg are increased. This has been studied quite a bit for plants adapted to growing in calcareous soils many of which secrete citrate from their roots.

Bjorn said:

That is true in concentrated solutions; on the ppm level calcium citrate is soluble (0.85g/l at 18C).

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Thanks Bjorn, I didn't know that!

myxodex said:

Yes, good point ... also citrate and malate together form a complex with Ca that is more soluble than either citrate or malate alone.

Citrate also helps to maintain phosphate availability when Ca and Mg are increased. This has been studied quite a bit for plants adapted to growing in calcareous soils many of which secrete citrate from their roots.

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Also interesting!

There always something to learn.Keep it going guys. Thx

myxodex said:

Yes, good point ... also citrate and malate together form a complex with Ca that is more soluble than either citrate or malate alone.

Citrate also helps to maintain phosphate availability when Ca and Mg are increased. This has been studied quite a bit for plants adapted to growing in calcareous soils many of which secrete citrate from their roots.

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I think Myodex read one of the links I posted on organic acids in plants when I started playing with lemon juice last year (which I still use today).

Lemon juice has a high concentration of citric acid, but also contains a decent amount of malic acid. (BTW Ed M has been using straight CA and MA instead of lemon juice for quite a while now with great results).

Just about all plants (not just select in calcareous habitats) use citric acid to control the pH in the rhizosphere (to around 5.8) for moving Ca, P and Fe into the plants. Calcareous species actually produce over 2X the amount of organic acids to do this.

There is other literature that the symbiotic fungi living in orchid roots produce a lot of OA's so again we see orchids adapting to low nutrient environments coopting other species to do their work.

Regulation of root pH is also important for nitrogen uptake, since root pH goes up as plants convert nitrate to ammonia (releasing OH in the process) and they have to release that base to bring in more nitrate (this is not pertinent to direct ammonia uptake).

So more than just simple pH and chelation benefits when using lemon juice with our ferts.


I started on thread on citric acid use (via lemon juice) about July of last year.