Lime is a common name for calcium oxide (CaO), which is a base. When lime is added to acidic soil, it reacts with the acid to form calcium salts, which are less acidic. This process helps to raise the pH of the soil, making it less acidic and more suitable for plant growth.

There are different types of lime used for soil amendment, including:

* Agricultural lime: This is the most common type of lime used for soil amendment. It is a finely ground form of limestone, which is a naturally occurring rock that contains calcium carbonate (CaCO3).

* Hydrated lime: This is a powdered form of calcium hydroxide (Ca(OH)2). It is more reactive than agricultural lime and can be used to quickly neutralize acidic soils.

* Dolomitic lime: This type of lime contains both calcium and magnesium. It is a good choice for soils that are deficient in magnesium.

It's important to note that not all soils need lime. Before adding lime to your soil, it's essential to test the soil pH and consult with a local agricultural extension service or a certified soil tester to determine the appropriate type and amount of lime to use.