The index scales printed below are those used by the standard 'bicarbonate' phosphate laboratory test. This is used by most UK labs including NRM & ADAS.

The Bicarbonate Method of Available Phosphate Measurement

Note: The interpretation scale above for phosphate cannot be used with the 'resin-extraction' method of phosphate determination used by Levington Agriculture in the UK. The Levington resin-extraction phosphate Scale is reproduced below. The Levington scale for other nutrients is the same is other labs.

The Levington Scale [Resin Extraction Method of Available Phosphate Measurement]