(Following on from 2015 Field Days – Dr Mel Fraser had some queries around Soil Acidity with regards to lime products and application rates.
Please find attached a short flyer that was produced by Andrew Harding (Rural Solutions SA) that explains the basics and contains analysis of local lime sources for the SE.)
In the laboratory soil pH can be measured in two ways.
There is pH (water) and pH (Calcium Chloride CaCl2). pH (CaCl2) is the preferred method for acid soils as it is a more stable and reliable method.
pH (CaCl2) is on average about 0.8 pH unit lower than pH (water) although this can vary from 0.6 to 1.1 pH unit. For example if a pH (water) is 5.2 then the pH (CaCl2) is about pH 4.4 (CaCl2).
All our liming recommendations are based on pH (CaCl2).