ASTM F1647-02a

These test methods establish the apparatus required, and standard calculations and procedures executed for quantifying the percent organic matter of volume ratio mixed putting green and sports turf root zone mixtures (except peat and other organic soils). Method A is performed by determining the loss on ignition (LOI). Method B or the Walkley Black method, on the other hand, is performed by a dichromate oxidation procedure whereby the color intensity of the reaction product is determined colorimetrically.