Baking soda is not good for raising pH as far as plants go. Sodium bicarbonate, too much sodium.
Oyster shell is just another form of calcium carbonate. Egg shell is calcium carbonate, too. Dolomite is calcium magnesium carbonate.
Dolomitic limestone is a pulverized lime which contains some amount (6-12%) magnesium, but not as much as pure dolomite would. Dolomitic lime is popular because plants need Mg too, as do microorganisms.
All of these materials could contain traces of other minerals. Some limestone deposits have iron.
I've been growing in soil for years without pHing anything. Dolomitic lime provides Ca and Mg and helps neutralize acidity long term; mainly counteracting the acidity of the sphagnum peat in the potting mix and future acidity generated by the plant roots exchanging H+ for other nutrient cations. If you ask me, pHing soil is antithesis to growing in soil.
If you want to grow in soil, understand what goes on in soil. The soil itself and the food web it nourishes handle the nuances of pH.
There are so many misconceptions
about pH. pH isn't all there is to nutrient availability and especially not in soil. Different nutrients are more/less soluble in water/plant available depending on pH. There is no exact, 'perfect' pH at which everything is just fine and beyond that biological activity in the soil is influencing the pH all the time. However, soil itself was designed to resist sudden pH changes. Quality soil and particularly earthworm castings, humus and compost have Cation Exchange and buffering capacity in their own right. They also contain humic substances, natural chelating compounds which increase nutrient availability.
CEC is very important to soil and what makes soil such a great medium to grow in. Soil has sustained life for hundreds of thousands of years, and whole forests of huge trees without anybody giving it pH up or anything really. Now, if you understand
cation exchange and base saturation you will see why people use dolomitic or garden lime in agricultural plots in certain areas and in potting mix.
Besides K, Ca and Mg are the most exchangeable base cations, and with low BS% pH generally falls. Potting mix has other considerations since it generally contains sphagnum peat moss which is acidic. Even if it came limed chances are it could use more from the start to prevent the accumulation of reserve acidity. Garden/dolo lime (carbonates) aren't very soluble in water; so it mainly dissolves over some period of time depending on particle size. There is some in soil as precipitate, acidity dissolves it gradually and the Ca, Mg cations are either taken up by the plant or adsorbed to soil colloids (preventing exchangeable H+). With this and microbial activity working as it should there is truly no need to pH anything.
Thank you, I will ask him next time I see him. I was hoping to find some info online as far as what he was saying, but wasn't having much luck. He was saying his first grow went terrible because of adding lime and it locked out a bunch of nutrients because of fermitation. Said that his Ph was on and everything else was right but the plants were showing all kinds of deficiencies and yield was low.
I talked to another grower who I know well and trust. She said that if you want to go from start to finish without PH'ing water/nutes, use dolomite lime for the immediate effects and oyster shell for the long term effects, so ultimately she suggested to amend both in the soil mix.
Lots of new growers like to blame their fuckups on products they used, it is interesting. Who knows what else could have gone wrong their. Although lime is difficult to over-do, there are instances in which it should not be used, or less should be used. Never use hydrated or slaked lime as they are much harsher. Probably no need to use lime if your water source is alkaline and has minerals dissolved in it already.