Resetting Phosphorus Cycling Research with 18Oxygen Isotopes

A hand holds soil in a field
Project Type
April 2020

The biogeochemical cycling of phosphorus (P) is the least understood of the carbon (C), nitrogen (N) and P trio. Agriculture has both depleted (erosion, harvest and removal) and enriched soils with P by adding inorganic P fertilizers to soils, and by transferring P harvested in grain to other soils via animal feeding and manure disposal. We live in a world with an altered P cycle that, on one end demands more P fertilizer to maintain agricultural productivity and on the other pollutes water, a dichotomy that society still does not know how to manage. Despite the magnitude of the challenge, we have a limited dynamic understanding of the mechanism governing inorganic and organic P cycling in soils, and poor predictive capacity to foresee future challenges or evaluate solutions.

We propose to employ a novel technique based on the oxygen-18 (18O) isotope to shadow-trace P cycling via phosphates, and to combine it with modeling to assess P transformation in soils. For that purpose, a team of Penn State researchers established a collaboration with Dr. D. Jaisi at the University of Delaware. We surmise that P research needs a reset, one that must be rooted on new means to trace and model P cycling, and that requires a bold approach to confront the twin challenges of supplying P to maintain agricultural productivity while reducing environmental pollution. 


Deb Prasad Jaisi

Deb Prasad Jaisi
Associate Professor, Department of Plant and Soil Sciences, University of Delaware