Calcium is an intergral part of our soils worldwide. The role Calcium plays in soil reactions and uptake of other trace elements is an important one.
The question we have to ask is in what form is the calcium we are applying and just how plant available is it. There are multiple forms of Calcium that can have effects on soils pH but are not that plant available. Below is a some information on varying forms of calcium.
Elementary calcium reacts with water. Calcium compounds are more or less water soluble. Calcium carbonate has a solubility of 14 mg/L, which is multiplied by a factor five in presence of carbon dioxide. Calcium phosphate solubility is 20 mg/L, and that of calcium fluoride is 16 mg/L. Calcium chromate solubility is 170 g/L, and at 0oC calcium hypo chlorate solubility is 218 g/L. Solubility of other calcium compounds lies between the levels of these examples, for example calcium arsenate 140 mg/L, calcium hydroxide 1.3 g/L and calcium sulphate 2.7-8.8 g/L.
Read this article for Soluble Calcium information