Fungal community structure from maize rhizosphere in different straw returning modes

This study examined the effects of different straw returning modes on the richness, evenness, and diversity of maize rhizosphere fungal communities. Maize rhizosphere soil samples were regularly collected using Illumina high-throughput under four straw returning modes: conventional returning (C), crushing deep turning (F), no tillage mulching returning (M) and straw mixing returning (S). Illumina high-throughput sequencing technology sequencing technology was employed for analysis. A total of 866, 107 effective sequences were obtained across all treatment groups, with 2, 472 operational taxonomic units (OTUs) were identified through cluster analysis at 97% similarity threshold. Compared with conventional returning (C), the crushing deep turning (F) treatment increased the richness and diversity of soil fungi in the maize rhizosphere, while no clear patterns were observed under the other treatments. Among the fungal genera detected in maize rhizosphere soil, Guehomyces, Solicoccozyma, Mortierella, and Talaromyces were the most dominant. Straw returning treatments improved soil fungal activity and increased the abundance of antagonistic fungi. However, it should be noted that pathogenic fungi also gradually increased during the later stages of the treatment. Correlation analysis of environmental factors indicates that soil nutrient and pH had the greatest impact on the fungal community structure of maize rhizosphere soil as returning time progressed. Functional analysis of the soil fungal community further revealed that straw returning treatments facilitated interactions between fungi and various soil nutrients, altered the functional structure of the fungal community, enhanced soil fungal activity, and promoted soil improvement. Among the four returning treatments, crushing deep turning (F) exhibited the most significant improvement effect.