The Hardwater-Calcium-Lime Thread

[VerdantGreen]

I could not find where in the paper there was the absolute conclusion which you stated. I did however find these points, some of which bolster my latest hypothesis;

what is your hypothesis Mm?

here is another paper, i cant quite find the one that first convinced me about it but will keep looking.
"Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids."
http://www.ncbi.nlm.nih.gov/pubmed/14971442

 

[VerdantGreen]

Spurr's quote from the old citric acid thread -
"Another very useful additive is citric acid. The reason citric acid is a great additive is it bonds to P anions keeping them soluble in the rhizosphere and soil solution. Also citric acid helps the Krebs cycle. The reason P anions are not needed by plants at the same level of N, K or Ca is that P anions are not readily available to plants in nature, thus they have evolved to use lower levels of P than other major elements. I could explain all the why's but this post would get long and IME most people don't care about the why's as it gets technical in the topic of soil science.

In short, P anions are not very mobile in the soil solution (thin layer of water surrounding particles in media, soilless and soil) and are readily bound and made insoluble to media particles and other elements and organic substances; critic acid prevents this. The soil solution holds cations in equilibrium to the cations held in cation exchange sites of media particles. Roots exude large amounts of citric acid that keeps P anions soluble in rhizosphere and soil solution. Roots also 'feed themselves' by exuding critic acid (and other acidic chemicals/substances) that mineralizes P anions from organic matter like soft rock phosphate, etc. "
few more links
http://www.plantstress.com/Articles/min_deficiency_m/P-bioavailability.pdf
http://www.nature.com/nbt/journal/v18/n4/full/nbt0400_450.html
http://link.springer.com/article/10.1007/BF02280176

 

[xmobotx]

i tend to speculate that; if you're going to feel the need to adjust pH down a little {as anything but a slight change wouldnt be a good idea} citric acid would be a preferable choice {and specifically in the form of lemon juice e.g. natural}

FTMP i find myself leaning to the camp that nutrient balance is a better school of thought than pH balance

but i dont find either to be a holy grail approach to organic gardening

i would say that is more along the lines of quality humus sources and choosing plant-based amendments w/ a little proper moisture levels thrown in for good measure

 

[Microbeman]

VG
You cannot make the absolute statement you have based on any of this info. You have read my hypothesis re H in soil solution

 

[BugJar]

I feel like there are really too many variables in such a dynamic environment to really have very many absolutes.

I follow the science but it is hard for me not to see some elements of mysticism at work.

The more we know the better off we are but at the end of the day you just kind of have to let go and let the soil do it's thing.

 

[VerdantGreen]

VG
You cannot make the absolute statement you have based on any of this info.

hi again Mm, like i said i have read a lot of information that illustrates the increased availability of phosphorous through the addition of citric acid (either as a root exudate or artificial addition)

from my understanding the papers i posted seem to accept this as a general fact - but there is some lack of understanding as to the exact mechanisms of the process - (largely as to whether or not it is only due to the increased acidity of the medium/rhizosphere, and whether or not plant roots exude just citrates or citric acid)

Results of model calculations show that with larger rates of citrate exudation, greater P availability is predicted. Exudation at a rate of 0.5 μmol citrate m–1 root day–1, which is in the range found for P-deficient plants, increased P availability almost 2-fold at fairly large phosphate loading of goethite (1.9 μmol m–2) and almost 30-fold at small phosphate loading (1.3 μmol m–2).

http://onlinelibrary.wiley.com/doi/...sCustomisedMessage=&userIsAuthenticated=false

another quote from spurr

[FONT=Arial, Helvetica, sans-serif]There are various benefits to using citric acid with organic growing besides to reduce pH* of water, ex.: (1) dissociation of insoluble ionic bonds such as P-Al, P-Ca, etc., thus making P soluble (i.e., plant available) and chelate the cations; and (2) mineralization of P from some organic matter such as soft rock phosphate (due to reasons such as lower pH of soil/soilless solution and direct affect of citric acid on SRF).[/FONT]

Phosphorus (P) is one of the most important nutrients limiting agricultural production worldwide. In acid and alkaline soils, which make up over 70% of the world's arable land, P forms insoluble compounds that are not available for plant use. To reduce P deficiencies and ensure plant productivity, nearly 30 million tons of P fertilizer are applied every year. Up to 80% of the applied P fertilizer is lost because it becomes immobile and unavailable for plant uptake. Therefore, the development of novel plant varieties more efficient in the use of P represents the best alternative to reduce the use of P fertilizers and achieve a more sustainable agriculture. We show here that the ability to use insoluble P compounds can be significantly enhanced by engineering plants to produce more organic acids. Our results show that when compared to the controls, citrate-overproducing plants yield more leaf and fruit biomass when grown under P-limiting conditions and require less P fertilizer to achieve optimal growth.

http://www.nature.com/nbt/journal/v18/n4/full/nbt0400_450.html

Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate.

http://www.ncbi.nlm.nih.gov/pubmed/14971442
---

You have read my hypothesis re H in soil solution

sorry if i'm being a bit dim, but you posted some disparate quotes from a paper that you say support your hypothesis, but i was unable to deduce your exact hypothesis from them.

cheers

VG

 

[bigshrimp]

"Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids."
http://www.ncbi.nlm.nih.gov/pubmed/14971442

This makes me think of fulvic acid,

which is a complex low molecular weight organic acid, and people also use as a ph down in hydro.

It would be interesting to know if fulvic acid would have the same effect on carbonates and P availability.

 

[VerdantGreen]

yes i think there are a few that have similar effect, oxalic acid was another one mentioned in the papers that i remember (this is what rhubarb has in high levels).

 

[VerdantGreen]

i am exactly the same.i never ever have problems.i think the minerals in the water actually help organics.

up to a point i would agree that they do. slight mineral content is probably preferable to nil.

but its worth also remembering that just because you dont have a problem with something, it doesnt mean that nobody else will either.
pH is a logarithmic scale, so pH of 9.1 is 100 times more acidic that pH 7.1 in the UK they add lime to the tapwater to 'make it better fro drinking' and at around 9 and high alkalinity (there is a difference between alkalinity and pH) i can assure you that, although i managed to grow decent plants using that water first round amended with citric acid, i wasnt able to recycle my soil until i started using rainwater, and in general i can tell my plants are a bit happier using rainwater.

im sure 9 out of 10 organic growers dont have to worry about high alkalinity water, and good organic soil is very forgiving, but i also like to try and do what is optimum for my soil, and i believe rainwater is optimum as long as it's not polluted. ( i generally add a little boiled tapwater to my rainwater to take the chill off it, so i guess i get a tiny bit of alkalinity from that)

VG

 

[BugJar]

ahhh pH and alkalinity there is a can of worms. dang chemistry.

honestly your water source and mineral content is going to make such an insignificant impact it is really barely worth mentioning.

as long as you aren't watering with distilled water you should be fine

 

[The Sensi Rebel]

I combat salt build-up and pH issues by adding more worms...lol...

Maybe its bro-science but I havent had any major issues since I've been doing this. They eat all the bad shit I guess and it also cuts down on rootbinding.
They eat bad shit and shit out black gold, what can I say lol.

 

[HidingInTheHaze]

...

 

[JKD]

Has anyone tried these potentially cost effective and perhaps counter intuitive approaches?

http://en.wikipedia.org/wiki/Lime_softening (Using hydrated (slaked) lime).

http://www.transtutors.com/chemistr...en-and-its-properties/softening-of-water.aspx(Using washing soda as opposed to baking soda.)

 

[dreadlock]

Hey jkd, interesting read.. I recently made a similar observation when using citric acid After reading this, with hard water after running out of ph down, great efficient alternative no doubt it lowered the overall ppm/ec and PH.. worth looking In to..

Update: lowered Ec to a point after which it would shoot up..

 

[HidingInTheHaze]

.

 

[xmobotx]

i would use distilled or rain water

RO seems more like a trend/fad than a legitimate solution for an organic grower

matter of fact; i have made similar suggestions many times in the past ~my 1st grow went south due to limed water from a cement well

distilled solved my problem then

 

[HidingInTheHaze]

Keep being thick headed and see how far you get.

 

[HidingInTheHaze]

not even worth leaving this here.

 

[xmobotx]

well @ least your trendy then w/ your RO filter and all

I don't use R/O as it is too costly and wasteful

 

[bigshrimp]

HITH- How has the straight ro water treated your plants?