Limitations of soil-applied non-microbial and microbial biostimulants in enhancing soil P turnover and recycled P fertilizer utilization - a study with and without plants

Michelle Natalie Herrmann; Lydia Grace Griffin; Rebecca John; Sergio F Mosquera-Rodríguez; Peteh Mehdi Nkebiwe; Xinping Chen; Huaiyu Yang; Torsten Müller

doi:10.3389/fpls.2024.1465537

Limitations of soil-applied non-microbial and microbial biostimulants in enhancing soil P turnover and recycled P fertilizer utilization - a study with and without plants

Front Plant Sci. 2024 Nov 12:15:1465537. doi: 10.3389/fpls.2024.1465537. eCollection 2024.

Authors

Michelle Natalie Herrmann¹, Lydia Grace Griffin^{1

2}, Rebecca John^{1

3}, Sergio F Mosquera-Rodríguez^{1

4}, Peteh Mehdi Nkebiwe¹, Xinping Chen^{5

6}, Huaiyu Yang^{5

6}, Torsten Müller¹

Affiliations

¹ Institute of Crop Science, Department of Fertilization and Soil Matter Dynamics, University of Hohenheim, Stuttgart, Germany.
² College of Agricultural and Environmental Sciences, University of Georgia Athens, Athens, GA, United States.
³ Institute of Biology, University of Hohenheim, Stuttgart, Germany.
⁴ Institute of Plant Physiology and Biochemistry, University of Hohenheim, Stuttgart, Germany.
⁵ College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, China.
⁶ Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing, China.

Abstract

Introduction: Phosphorus recovery from waste streams is a global concern due to open nutrient cycles. However, the reliability and efficiency of recycled P fertilizers are often low. Biostimulants (BS), as a potential enhancer of P availability in soil, could help to overcome current barriers using recycled P fertilizers. For this, a deeper understanding of the influence of BSs on soil P turnover and the interaction of BSs with plants is needed.

Methods: We conducted an incubation and a pot trial with maize in which we testednon-microbial (humic acids and plant extracts) and microbial BSs (microbial consortia) in combination with two recycled fertilizers for their impact on soil P turnover, plant available P, and plant growth.

Results and discussion: BSs could not stimulate P turnover processes (phosphatase activity, microbial biomass P) and had a minor impact on calcium acetate-lactate extractable P (CAL-P) in the incubation trial. Even though stimulation of microbial P turnover by the microbial consortium and humic acids in combination with the sewage sludge ash could be identified in the plant trial with maize, this was not reflected in the plant performance and soil P turnover processes. Concerning the recycled P fertilizers, the CAL-P content in soil was not a reliable predictor of plant performance with both products resulting in competitive plant growth and P uptake. While this study questions the reliability of BSs, it also highlights the necessity toimprove our understanding and distinguish the mechanisms of P mobilization in soil and the stimulation of plant P acquisition to optimize future usage.

Keywords: P availability; P turnover; biofertilizers; biostimulants; phosphorus solubilizing bacteria; recycled fertilizers; sewage sludge ash; struvite.