Is dolomite lime essentially the same as Cal-Mag?

ASYD PAPI

New Member
The title says it all. Reason I ask is because the price difference is insane! Cal-mag that's currently in stock, 1L bottle is 100$+ and, I haven't looked at them yet, but, I've heard dolomite lime is better for your plants/soil and like 10-50$ depending on how much you want.
 

Three Berries

Well-Known Member
No they are not the same. The limestone is a alkaline buffer as it has the negative carbonate ion CO3, CaCO3. For the Ca to be released for the plant to use it has to be stripped by active + ions from an acid. This will raise or maintain the pH depending on quantity. It is not soluble in water and needs acid to free up the Ca.

Cal-Mag is Calcium Nitrate and Magnesium Nitrate. These are acid based using nitric acid to dissolve calcium or magnesium to form the + Nitrate ion (NO3). Calcium Nitrate Ca(NO3)2

The nitrates are very soluble in water and in so doing splits the molecule up to free Ca and HNO3, nitric acid. The nitric acid will go on to react with the carbonate to release the Ca from that too.

Here is the formula for the degradation of Magnesium Nitrate 2 Mg(NO3)2 → 2 MgO + 4 NO2 + O2.
 
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Three Berries

Well-Known Member
Here's what you do with calcium carbonate aka white caulk, so that it is readily available to a plant.

Mixing it with vinegar will produce a very water soluble calcium acetate. The calcium acetate will offer up its Ca easily to the roots and leave behind some Acetic Acid, aka vinegar. Acetic acid is organic meaning its carbonic acid based and will decompose to CO2 and water when running up against those -OH ions. Acetic Acid CH3COOH

 

thumper60

Well-Known Member
The title says it all. Reason I ask is because the price difference is insane! Cal-mag that's currently in stock, 1L bottle is 100$+ and, I haven't looked at them yet, but, I've heard dolomite lime is better for your plants/soil and like 10-50$ depending on how much you want.
Yikes 100 plus for a qt of cal-mag time to move.50 lb bag of dolomite is 5 bucks here it is slow to break down in soil an has no mag in it. Its used mostly as a ph buffer.
 

Three Berries

Well-Known Member
Limestone is quite variable as to the Mg and Ca content depending on source and is usually graded with a CCE number..

Purity – calcium carbonate equivalent (CCE)
The purity of limestone is expressed as calcium carbonate equivalent (CCE). It is a laboratory measure of how much calcium carbonate reacts in a given sample. Limestone should have a CCE of at least 90 percent.

Liming material CCE can range from 50 to 175 percent. Much of the country’s ag lime contains many impurities – such as sand, clay, iron and lead – which lower its CCE.

 

jimihendrix1

Well-Known Member
Best to combine both Calcitic Lime, and Dolomitic Lime
2 parts Calcitic, to 1 part Dolomitic if using peat based medium.

Promix BX uses this ratio in their mix. Calcitic is faster at affeting PH, and the Dolomitic is better at long term.


What are The Benefits of Calcitic Lime?
Calcitic lime has long been the preferred treatment for acidic soil. A thorough application of pulverized limestone tilled into the soil raises the pH to a neutral level, increasing crop yields and improving overall soil health.

The main “ingredient” in calcitic lime is calcium carbonate, which is why many people ask if calcium carbonate is the same as limestone. It counteracts the acidification of field soil. Acidification is the natural result of nitrogen heavy fertilizing practices. By adding a lime treatment, you can undo the damage caused by nitrogen treatments without counteracting the benefits.

In addition to neutralizing pH, lime also encourages the growth of micro-organisms that contribute to plant health. With the combination of helpful micro-organisms and pH balanced soil, plants and crops will thrive.

Calcitic lime works effectively, even with one treatment. Although waiting for the treatment to become fully effective requires some patience, if you plant your fields every year, calcitic lime will likely be the only treatment you’ll need to balance the pH level.

Calcitic lime also works more quickly than dolomite lime: Calcium carbonate is better at balancing pHs than magnesium carbonate, and calcitic lime contains much higher levels of calcium carbonate than dolomite lime.

What are Calcitic Lime’s Limitations?
Typical calcitic lime treatments require some patience. If you apply dry calcitic lime on a dry field, you will need to wait for rain for the treatment to work. Water is required for the chemical process to begin.

You must also till the soil immediately after the lime application. Lime sitting on the surface of your soil will not be nearly as effective as lime that is well mixed into the soil.

But the main drawback to calcitic lime is its simplicity. It is designed to neutralize pH and replace depleted calcium in the soil, and it won’t replace depleted magnesium. If your fields are producing magnesium deficient crops, you will find that calcitic lime treatments won’t improve your crop health.

However, these are special conditions. Most soils only need calcitic lime as their magnesium levels are already optimal. For most applications, calcitic lime is best. But you should always double-check the mineral content in your soil just to be sure.

What are the Benefits of Dolomite Lime?
When it comes to raising and balancing the pH of your soil, both calcitic and dolomite lime are effective. However, unlike calcitic lime, dolomite lime also contains large amounts of magnesium. Magnesium is an essential mineral for healthy soil.

Grass tetany, a metabolic disease affecting cattle and sheep livestock, is distinguished by magnesium deficiency. Fast growing spring grass will often be devoid of the magnesium livestock need to survive, making dolomite lime an important consideration if you are using your fields for livestock grazing.

Magnesium deficient plants are often yellower, have shorter root systems, and produce noticeably lower yields than plants grown in healthy soil. Fields home to crops that are taxing on potassium levels — such as corn fields — can also benefit from magnesium treatments.

If your field contains a calcium-to-magnesium ratio of 6:1 or greater, your field is considered to be magnesium deficient, and you should strongly consider using dolomite lime to bring your mineral balance into balance. Proper calcium-to-magnesium ratios are important for ensuring healthy growth.

VIEW OUR LIME PRODUCTS!

What are Dolomite Lime’s Limitations?
However, while dolomite lime works well if you need to raise your magnesium levels, excess magnesium creates new dangers.

Too much magnesium can cause your soil to become overly compact, deterring crop growth while also making the soil more difficult to water efficiently. It can also fuel rampant weed growth, further impeding the growth of your crops.

Magnesium needs in your soil often correspond with your soil consistency. Magnesium deficiency is much more common in quick draining soils, especially those that are sandy, while clay and clay loam soils rarely suffer from magnesium issues.

If your fields contain a large amount of clay soil, it is unlikely that you will want to use dolomite lime. In fact, because dolomite can make soil compaction worse, an ill-advised dolomite application can seriously harm denser clay soils.

Additionally, undoing a dolomite lime treatment can be tough. Sulphur and nitrogen treatments can bring your magnesium levels back into line, but these treatments are time-consuming and can be expensive. So it is much cheaper and efficient to avoid adding extra magnesium into your soil in the first place.

Plus, if you don’t need dolomite lime, calcitic lime simply works better at restoring pH. Even though magnesium carbonate is alkaline just like calcium carbonate, it doesn’t work quite as effectively. So if you are merely looking to correct the pH balance, you are much better served choosing calcitic lime.

With this in mind, you should only use dolomite lime if you need to add magnesium to your soil. The risks posed by introducing too much magnesium far outweigh any benefits. As always, if you are unsure about the nature of your soil, make sure to contact a professional to measure your soil pH and mineral content before ordering a lime treatment.
 

GroBud

Well-Known Member
As mentioned unless your soil is low ph and you need to raise that ph I wouldn't use dolomite lime. Gypsum is a calcium nutrient that doesn't effect soil ph, Epsom salt is magnesium that doesn't effect soil ph.
 

Mattsmith1871

Active Member
The title says it all. Reason I ask is because the price difference is insane! Cal-mag that's currently in stock, 1L bottle is 100$+ and, I haven't looked at them yet, but, I've heard dolomite lime is better for your plants/soil and like 10-50$ depending on how much you want.
I don't know if they have it where you are but try vitalink calmag, great stuff and it's 10-20$ a bottle.
I got mine from amazon and my plants look great.
 

Three Berries

Well-Known Member
Here's an off the shelf commercial deicer that is essentially a cal mag treatment. Made from dissolving limestone with acetic acid. I bet it's cheap if they use it to spray on roads.

CMA – Calcium Magnesium Acetate
CMA is granulated calcium magnesium acetate, a patented chemical formulation from dolomitic lime and acetic acid. It was first identified as a low corrosion, environmental alternative to road salt by the U.S. Federal Highway Administration in the late 1970’s. It was then tested and commercially developed. Today, CMA is used worldwide to answer environmental concerns and solve problems associated with corrosion and concrete spalling.

CMA is generally used in a solid form and spread on the surface like other deicers. Although CMA is effective to the same temperatures as salt, CMA has many unique performance characteristics. Therefore, first-time users should review product application guidelines closely. For answers to frequently asked questions regarding CMA, please see the information sheet.

CMA is also used in liquid form, generally for anti-icing roads and bridges. Here, the fluid is applied prior to a storm event to prevent snow and ice from bonding to the surface. Liquid CMA is typically formulated in the field from dry CMA.

 

Milky Weed

Well-Known Member
Here's an off the shelf commercial deicer that is essentially a cal mag treatment. Made from dissolving limestone with acetic acid. I bet it's cheap if they use it to spray on roads.

CMA – Calcium Magnesium Acetate
CMA is granulated calcium magnesium acetate, a patented chemical formulation from dolomitic lime and acetic acid. It was first identified as a low corrosion, environmental alternative to road salt by the U.S. Federal Highway Administration in the late 1970’s. It was then tested and commercially developed. Today, CMA is used worldwide to answer environmental concerns and solve problems associated with corrosion and concrete spalling.

CMA is generally used in a solid form and spread on the surface like other deicers. Although CMA is effective to the same temperatures as salt, CMA has many unique performance characteristics. Therefore, first-time users should review product application guidelines closely. For answers to frequently asked questions regarding CMA, please see the information sheet.

CMA is also used in liquid form, generally for anti-icing roads and bridges. Here, the fluid is applied prior to a storm event to prevent snow and ice from bonding to the surface. Liquid CMA is typically formulated in the field from dry CMA.


That’s extremely interesting, so this is the liquid they spray in lines on the road before snow storms. I always wondered what it actually was.
 

Three Berries

Well-Known Member
That’s extremely interesting, so this is the liquid they spray in lines on the road before snow storms. I always wondered what it actually was.
I always heard it was beet juice. I know it's sticky. But yes they spray it on the bridges and at intersections out on the highways around here.
 

Three Berries

Well-Known Member
So I got some Calcium Acetate the other day. It is a dry powder that is very hydroscopic so needs to be kept dry, inhalation hazard too. Obviously it's very water soluble. 1 tlbs (6 gr) disappeared in a cup of water.

The solubility of calcium in water

nitrate @20 0C is very high: 1212 g/L.

sulfate (gypsum drywall plaster of paris) @ 25C 2.6 g/L gypsum

acetate @ 20C 347 g/L 6 gr per tbls

Magnesium Sulfate Epsom salt

@ 20C 351 g/L 17 gr per tbls
 
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