This European Standard specifies two methods (method A and method B) of measuring the effect of the addition of any liming material claiming liming effect to the soil, using the same basic principles. Method A measures the changes to the soil pH resulting from the addition af any material claiming a liming effect to a standard soil, measured over a period of one month. Method B assesses the efficiency of any material claiming a liming effect, using a range of defined soils and measured over a period of up to 2,5 years.