Originally Posted by stimpy
Bill. Did you calcitic lime.
I am glad someone caught ICT's comments about the Dolomite, I knew it had to be a typo, but some might not.. Dolomite can not be used to lower Magnesium levels since it also contains Magnesium. On the other hand Calcitic lime contains no magnesium and can be used to raise the base saturation of calcium and lower the base saturation of magnesium.
Sulfur can also be used to drive down the magnesium saturation. It takes ruffly 3lbs of sulfur to drive off one lb of magnesium. If Ph levels are already high, Gypsum, instead of calcitic lime, can also be used to lower magnesium levels as it contains calcium as well as sulfur. Depending on Calcium saturation levels, it might take a mixture of calcitic lime and gypsum to get the desired results. Whereas the calcium lime will lower Mg saturation levels on a lb for lb basis, it is best to raise calcium levels using calcitic lime first before adding any gypsum.
On the subject of ratios, these numbers are only relevant if you have adequate amounts of each nutrient. 8lbs of calcium and 1 lb of magnesium will give you a ratio of 8:1, but it wont give you an adequate amount of either nutrient to grow a crop.