Liming materials are products that can neutralise soil acidity (See Information Sheet 6.4: Managing soil acidity). These products work by reducing the amount of hydrogen (H) ions in the soil thus lowering the pH. This reduces the amounts of toxic elements like aluminium (Al) and manganese (Mn), while improving the availability of several plant nutrients and stimulating root growth and soil biological activity. In this information sheet, the key benefits of liming are highlighted, some best practices for the use of lime are outlined and various aspects of lime quality are considered. Advantages of liming of acid soils: Increases soil pH, Lowers toxic levels of Al and Mn, Increases availability of phosphorus (and most other nutrients) for crop uptake, Adds calcium (Ca) (and sometimes magnesium (Mg)) to the soil, Improves nitrogen mineralisation and availability, Improves soil biological function, Enhances soil aggregation, Increases soil cation exchange capacity. Risk of overliming ("limeshock"): May cause an excessive increase in soil pH, Leads to