Soil C/P Stoichiometry Mediated Microbially Driven Phosphorus Mobilization: New Insight in Soil P Management

Phosphorus (P) is one of the major limiting factors for agricultural crop production. Although a high-chemical-P fertilizer input ensures high yields, it also leads to increased soil P accumulation issues and depletion of non-renewable P resources. It is a great challenge to optimize P inputs, improve soil P use efficiency, and maintain high crop yields. This study aims to review the current efforts to utilize the soil accumulated-P (due to excessive P application) efficiency by maximizing biological potential and to provide feasible insights into nature-based solutions for high-P soil utilization in the future. Currently, we are confronted not only with the longstanding challenges of low P fertilizer utilization rates and substantial soil P accumulation but also with the emerging issue of an ongoing decline in soil C/P stoichiometry. Therefore, improving the biological potential of soil indigenous microorganisms using C/P ratio principles could be an effective approach to promote soil P mobilization and utilization by crops. In this context, we highlighted key mechanisms involved in microbially-mediated soil-P mobilization by building up microbial biomass P pool. Our findings demonstrate that the use of carbon (C) sources enhanced the biological potential for high-P utilization in soil. The higher or lower soil C/P causes competition among plants and microorganisms. However, the soil and microbe C/P thresholds could be a predictor of an intensive competition between plants and microorganisms for P. In this view, we suggest that integrating C/P stoichiometry principles into soil P management could be effective for optimizing P fertilizer application as part of sustainable agricultural practices.