The Addition of a High Concentration of Phosphorus Reduces the Diversity of Arbuscular Mycorrhizal Fungi in Temperate Agroecosystems

Phosphorus (P) is an essential macronutrient crucial for both plant growth and crop production, playing a pivotal role in agriculture since the early 20th century. The symbiotic relationship between AMF and plants serves as a classic illustration. These fungi play a regulatory role in the growth and development of plants, especially in facilitating the absorption of P and carbon molecules by plants. While there has been a growing body of research on the community assembly of arbuscular mycorrhizal fungi (AMF) in recent decades, our knowledge of the processes governing the coexistence of these AMF communities influenced by P in agroecosystems remains limited. To investigate the impact of various P fertilizers on AMF communities in temperate agroecosystems, this study was conducted using soils sourced from wheat-maize rotation farmland at Henan Agricultural University Yuanyang Base. With the Illumina MiSeq high-throughput sequencing technique, we systematically examined the taxonomic composition of soil AMF at the Yuanyang Base of Henan Agricultural University in a wheat-maize rotation agricultural field. Our primary objective was to unravel the mechanisms behind AMF community assembly and stability under varying P gradient fertilization conditions. Nonmetric Multidimensional Scaling (NMDS) analysis revealed significant differences among AMF communities in field soil subjected to various treatments (p < 0.05). A torus translations test demonstrated positive associations with the three treatments in 36 out of the 51 examined AMF operational taxonomic units (OTUs), making up 70.59% (p < 0.05) of the results. Furthermore, 37.84% (14/37) of the OTUs displayed preferences for the low P concentration treatment, while 34.29% (12/35) and 32.26% (10/31) favored medium and high P concentrations, respectively. An analysis of the Normalized Stochasticity Ratio (NST) and Checkerboard Score (C-score) indicated that in temperate agroecosystems, deterministic processes predominantly governed AMF in all treatment groups, with high P conditions exerting a stronger influence than low or medium P conditions. This study underscores the profound impact of long-term P fertilizer application on AMF community structures within temperate agricultural systems employing wheat-maize rotation. Additionally, it highlights the dominant role played by deterministic processes in shaping the assembly of AMF communities in these temperate agricultural systems that use P fertilizers. These findings emphasize the need for balanced nutrient management, particularly concerning P, to ensure the stability of AMF communities.