Tillage Practices and Residue Management Manipulate Soil Bacterial and Fungal Communities and Networks in Maize Agroecosystems

Tillage practices and residue management are highly important agricultural practices. However, very few studies have examined the influence of tillage practices and residue management on both bacterial and fungal communities and network patterns in consecutive years. We examined the effects of different tillage practices, including no tillage, rotary tillage, and deep tillage, on soil bacterial and fungal communities and co-occurrence networks following residue removal and residue retention in 2017 and 2018. This study showed that both bacterial and fungal communities were unaffected by tillage practices in 2017, but they were significantly impacted in 2018. Soil fungal operational taxonomic unit (OTU) richness was significantly enhanced by deep tillage compared with no tillage in 2018, while bacterial OTU richness was unaffected in either year. Tillage practices had differing effects on soil microbial co-occurrence networks, with rotary and deep tillage increasing the complexity of bacterial networks but simplifying fungal networks. However, residue retention only induced a shift in the fungal community and simplified soil bacterial and fungal networks in 2018. This study highlights the dissimilar responses of bacterial and fungal networks to tillage practices and emphasizes that tillage practice is more important than residue management in shaping soil microbial communities.