Conclusions and Way Forward

Abstract

With an increasing number of researchers using the δ18OP method to investigate P cycling in the environment, it is necessary to conduct an inter-laboratory comparison study for the purification protocol as well as the measurement of silver phosphate with the TC/EA-IRMS like Watzinger et al. (2021) did. For the δ18OP method to progress, further fundamental research as well as field and laboratory studies need to be conducted. To the best of our knowledge, the effect of synthesizing enzymes on the δ18OP has not been investigated yet, despite the importance of those enzymes in the P cycle.