4B4 pH of 1:5 soil/0.01 M calcium chloride extract – following method 4A1 (with stirring during measurement)

This method is identical to Method 4B2 except the CaCl₂ solution is mechanically stirred during pH measurement. This option suits some automatic pH measuring robots. All pH measurements should be completed on the same day, ideally within 4–6 h.

Report pH (1:5, soil/0.01 M CaCl₂) on an air-dry basis.