What is good quality lime?
Good quality calcitic (agricultural) lime should have a calcium (Ca) content of > 35% and a calcium carbonate equivalent (CCE) value of > 70%. Normally the magnesium content of calcitic lime is < 1%.
Good quality dolomitic lime should have a calcium (Ca) content of 20-24% and a magnesium content of 10-14%, with a calcium carbonate equivalent (CCE) value of > 70%.
Lime fineness is also important. The finer the lime, the faster it will react in the soil to correct soil acidity. Lime that is made up of big lumps has very little value in correcting soil acidity as it will take years to react. It is expensive to crush lime, so very fine lime will become expensive. It is important to find a balance between the fineness (mesh size) and cost.
Always test your soils before applying lime