Phosphorus Supply Increases Nitrogen Transformation Rates and Retention in Soil: A Global Meta‐Analysis

This is the authors' abstract. We don't add key points for this paper.

Interactions between nitrogen (N) and phosphorus (P) are important for plant growth and ecosystem carbon (C) sequestration. While effects of N supply on P dynamics have been much studied, much less is known about the opposite (P‐effect on N). We conducted a meta‐analysis by compiling a total of 1,734 individual experimental observations from 116 peer‐reviewed publications to assess P‐addition effects on soil N dynamics. Globally, P additions increased the soil total nitrogen (TN) pool, potentially as a result of enhanced plant and microbial immobilization and reduced N losses, with a stronger effect detected under longer duration of P addition (≥5 yr). A coupled increase in soil organic C with TN signifies the fundamental role of exogenous P supply in enhancing soil C sequestration. Phosphorus addition accelerated some of the soil N cycling processes including gross N mineralization, gross nitrification, and denitrification, with the effect sizes varying among ecosystem types and increasing with P addition rates. Our results indicate the fundamental role of P in affecting soil N pools and processes, and highlight the efficacy of P supply in sequestering soil C and mitigating global C emission.