This document specifies the method for the determination of the EDTA soluble phosphorus content of inorganic fertilizers. The method is applicable for fertilizers composed of or blended from multiple sources such as superphosphate, ammonium phosphate, triple superphosphate, and/or nitrophosphate. It is not suitable for fertilizers containing calcium magnesium phosphates.All current amendments available at time of purchase are included with the purchase of this document.