The difference between Calcitic (CaCO3) and Dolomitic Lime [CaMg(CO3)] is:
- Calcitic lime is a ground lime which has calcium carbonate in it (Peters, Kelling & Shulte, 1996)
- Dolomitic lime is a limestone which contains a combination of calcium carbonate, and magnesium carbonate (Peters, Kelling & Shulte, 1996)
The purity of lime depends on how much calcium carbonate (CaCO3) is in the product. This is a measure of how much calcium carbonate is in a given amount of product, and how much acid that amount will neutralize. The calcium carbonate equivalence in lime which is pure, is 100% (Peters, Kelling & Shulte, 1996).
A higher magnesium amount in dolomite lime, will mean a higher calcium content, because magnesium has a low atomic weight (Peters, Kelling & Shulte, 1996).
****It is usually the case that the higher the calcium carbonate equivalence, the higher the neutralizing capability of the lime
Fine or Course:
Limestone dissolves slowly, and it is effective around a small surface area which is around each particle.
However, if the surface area is increased, solubility also increases. If you reduce the surface radius of a particle of lime by half, the surface area increases by 50%.
All this means: A FINER GRADE of lime has a larger surface than COARSER GRADE of lime. Also, an increased finer grade lime has increased solubility—-So it dissolves at a faster rate (Peters, Kelling & Shulte, 1996).
Dolomitic vs Calcitic Lime
There is not much difference in calcitic lime, and dolomitic lime, in their abilities to neutralize soils, that are acidic (Isleib, 2015)
THE MAJOR TWO THINGS TO CONSIDER ARE THE pH AND MAGNESIUM LEVEL IN THE SOIL WHEN DECIDING WHICH LIME TO USE (Isleib, 2015)
- If liming is not recommended, use GYPSUM—pH will be lowered, and calcium will be added (Isleib, 2015)
– Both dolomitic lime, and calcitic lime will add sufficient calcium. Dolimitic Lime will aLso add magnesium (Isleib, 2015)
-Adding High Rates of Calcitic lime or gyspsum, may induce magnesium deficiency, if soil is already low in Magnesium.
Peters,J.B., Schulte, E.E., Kelling, K.A.(1996). Choosing Between Liming Materials. Retrieved from http://corn.agronomy.wisc.edu/Management
Isleib, J. (2015). Should I use Dolomitic or Calcitic Lime? Retrieved from: http://msue.anr.msu.edu/news/should_i_use_dolomitic_or_calcitic_lime