Is soil phosphorus fractionation as valuable as we think?

Abstract

The recent article by Barrow et al. (2020) concerning "The soil phosphate fractionation fallacy" is a welcome cautionary paper for phosphorus scientists to question how they approach the interpretation and practical use of phosphorus fractions in understanding the nature of soil phosphorus. The recent Commentary article "Navigating limitations and opportunities of soil phosphorus fractionation" published alongside by Gu and Margenot (2020) further extends that conversation about the value and use of phosphorus fractionation and lucidly argues that all may not be lost when pondering the usefulness of a long legacy of phosphorus fractionation manuscripts, particularly since the advent of the Hedley et al. method (Hedley et al. 1982) and modifications by Tiessen and Moir (1993). I will not revisit their discussion, but reflect more broadly on my experience of the usefulness of phosphorus fractionation in driving forward a functional understanding of soil phosphorus behaviour, and more specifically, plant phosphorus acquisition. The aim of this Commentary is simply to challenge perceptions around exactly how useful phosphorus fractionation schemes are, and, perhaps lower the number of manuscripts submitted that still equate discrete fractions with specific phosphorus minerals in soil.