Deep insights into the diversified cropping and their impact on arbuscular mycorrhizal fungi: A global meta-analysis

Abstract

Arbuscular mycorrhizal fungi (AMF) play a pivotal role as essential symbionts in agricultural soils, forming mycorrhizal associations with a wide array of crops. Meanwhile, crop diversification is the cornerstone of sustainable agricultural practices. However, the complexity of cropping systems and the varying environmental conditions across different regions limit our full understanding of AMF in crop diversification. Herein, we conducted a global meta-analysis, integrating observational data from 82 publications and 86 field studies on diversified cropping systems, such as cover crops, intercropping and crop rotation. Our objective was to investigate the effects of different diversified cropping patterns on AMF abundance and diversity. Results indicate that compared with fallow, cover crops significantly enhanced the total colonization, spore abundance, hyphal length density and extraradical biomass of AMF, with increases of 34.42 %, 54.66 %, 47.50 % and 36.74 %, respectively. Intercropping significantly enhanced the total colonization and hyphal length density of AMF compared with mono-cropping, with increases of 19.76 % and 24.54 %, respectively. In contrast to continuous cropping, crop rotation had no effect on AMF abundance, but it reduced the AMF richness in crop roots by 42.52 %. Furthermore, the response of AMF abundance to different cropping systems was regulated by climate conditions, soil properties and agronomic practices. In summary, our findings highlight that optimizing AMF abundance and diversity in agro-ecosystems requires considering specific cropping practices and environmental factors when implementing diversified cropping systems. In particular, cover crops and intercropping significantly enhance the AMF abundance, offering valuable insights for the future optimization of agro-ecosystems and AMF management.