Rapid method for the estimation of total phosphorus in soils

✍ Scribed by R. S. Beckwith; I. P. Little

• Publisher: John Wiley and Sons
• Year: 1963
• Tongue: English
• Weight: 412 KB
• Volume: 14
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740140103

✦ Synopsis

Abstract

Some Queensland soils fail to release the whole of their phosphorus during extraction for 4 h. with boiling hydrochloric acid unless previously ignited. Loss of phosphate from extracts of non‐ignited soils is apparently due to titanium oxides which may either adsorb dissolved phosphate during the period of the extraction, or dissolve partially and reprecipitate when the soil extract is diluted and cooled. Pre‐ignition renders soil‐titanium less soluble and allows complete recovery of phosphorus in soils with boiling acid.

Phosphorus in such solutions can be conveniently determined by the molybdovanado‐phosphoric acid method after fuming off with perchloric acid. An interfering element (probably cerium) has been encountered in many soil extracts but a reduction treatment readily overcomes this interference.