Garden Lime

Agricultural lime, also called garden lime or liming (soil), is a soil additive made from pulverized limestone or chalk. The primary active component is calcium carbonate. 

Effects on soil:

• it increases the pH of acidic soil (the higher the pH the less acidic the soil)
• it provides a source of calcium for plants
  
• it permits improved water penetration for acidic soils
  

Gypsum is also used to supply calcium for plant nutrition when there is high salt and or magnesium present.  Dolomite  is also used to supple calium for plant nutrition when there is low magnesium content. The concept of "corrected lime potential" to define the degree of base saturation in soils became the basis for procedures now used in soil testing laboratories to determine the "lime requirement" of soils.[1]

Other forms of lime have common applications in agriculture and gardening, including dolomitic lime and hydrated lime. Dolomitic lime may be used as a soil input to provide similar effects as agricultural lime, while supplying magnesium in addition to calcium.

In livestock farming, hydrated lime can be used as a disinfectant measure, producing a dry and alkaline environment in which bacteria do not readily multiply.

In horticultural farming it can be used as an insect repellant, without causing harm to the pest or plant.