3 way liming mix

[Lost in a SOG]

Different sources of calcium of different particle size have different liming effects at different pHs..

really acidic soil with calcium carbonate flours added will buffer really fast but crab shell bits in around normal 6-6.5 pH soil wont do anything long term.

Bacteria work hard to maintain the pH so only mixing in something fairly reactive, like too much oyster shell flour or dolomite will cause really significant swings.

Ill throw my hat in the "Rock dust seems mostly unreactive in terms of pH" ring, ime. But i dont add crazy amounts only about 1/3 cup/cu.ft.. with the same in azomite. I do test my mixes with a professional soil pH probe though.

 

[Bush Doctah]

Thanks Lost in a SOG. Of course, the microbes are key to keeping pH in balance (a duh! moment for me, for sure). I read Teaming with Nutrients most recently so I guess my head is still in that chemical-ish space. Thanks for bringing me back to earth!
BD

 

[thailer]

https://ir.library.oregonstate.edu/downloads/m613mx90d

learning about Calcium Carbonate Exchange (CCE) really helped explain how lime works for me. the pdf link compares calcium carbonate sources like shrimp and crab meal to agriculture lime, dolomite, etc as well as explaining how it works. calcium carbonate as crab meal doesn't buffer soil like calcium carbonate like CaCO3.

 

[Bush Doctah]

Thanks thailer again for the great information.

I found the discussion of CEC made perfect sense: high CEC soils hold more of the Ca ions making CaCO3 more available for liming and also holding them longer in the soil by preventing them from being washed out. What I found somewhat confusing, because there was limited explanation, was the last sentence in Fig. 3, about the liming process continuing until all of the lime has reacted.

If all the acidic soil particles have been reacted with, but there still remains CaCO3 held because of a high CEC soil, like we try to build, does that mean that this offers a sort of longer term liming potential? So, if something acidic is added to the soil it could still be neutralized by the held lime? Does this make it difficult to overlime, although not impossible? Finally, going back to my question about liming rates for peat only vs. the base mix, is this why it seems not to matter which one you use?

The discussion about fineness, was good. Glad to know that our relatively fine oyster shell flour should lime quickly, meaning we don't have to worry about that during the cycling/cooking period.

I feel for farmers with different levels of soil acidity in the same field. What a nightmare that could be to deal with. Much respect to farmers!

BD

 

[Bush Doctah]

Liming peat and leaf mold mixes

Liming peat and leaf mold mixes

Should I adjust my liming to account for a mix of 2/3 peat to 1/3 leaf mold? Short and sweet for once!

BD

 

[thailer]

well i think someone else would be better at answering this. my basic understanding is that acids are released all the time from peat breaking down, fertilizer breaking down, compost decomposing further, mulch decomposing, etc that eventually calcium carbonate runs out if you are not reapplying it. in a no till potting soil it is usually added after each cycle and i read on KIS Farms website that after the 5-6th cycle a soil test would be needed due to the buildup of lime.

the CCE of lime is how quickly it reacts to acid. So crab meal is calcium carbonate but it doesn't buffer pH like the CaCO3 from lime.

CEC is the measure of exchange sites on a medium like peat, coir or even vermiculite.

 

[h.h.]

While the plant emits acids, it retains calcium.
It doesn't go anywhere until you harvest.
If you have nothing else producing acidic conditions, there's no need to buffer further.
Lime salesmen disagree.