PhD defence: Aggregate size matters: The impact of soil aggregation on microbial community assembly and suppression of tomato

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The growing global population is challenging agricultural food production. However, the heavy reliance on chemical fertilizers in traditional agriculture has led to various problems. To ensure a sustainable food supply, alternative approaches, such as bio-organic amendment are needed.

Bio-organic fertilizers have shown promise in improving soil quality and health for agricultural production. However, the precise mechanisms underlying how bio-organic amendments enhance soil quality, concerning the interplay between soil structure and the soil microbiome, remain unclear.

Soil structure plays a pivotal role in structuring soil microbiome. Different sizes of soil aggregates provide distinct micro-environments for microorganisms, influencing microbial community composition and functions. Understanding this interplay between soil structure and the microbiome is essential for agricultural production and disease suppression.

This thesis aims to investigate the impact of fertilizer amendments on microbial community assembly and disease suppression, focusing on the fine-scale heterogeneity of soil aggregates. The research examines how bio-organic amendments shape microbial communities within soil aggregates and how these changes affect disease suppression. The findings suggest that soil aggregate size significantly influences the bacterial community composition, assembly processes, and succession. Additionally, micro-aggregates are crucial microhabitats for the pathogen Ralstonia solanacearum, and bio-organic amendments can decrease the abundance of micro-aggregate size classes and enhance microbial inhibition of pathogen in micro-aggregates, promoting soil health.

Overall, this thesis underscores the significance of fine-scale soil aggregate heterogeneity in microbial ecology and function research. It elucidates the mechanisms of disease suppression induced by soil amendments, emphasizing the interplay between soil structure and the soil microbiome in agriculture.

Start date and time
End date and time
Location
Academiegebouw, Domplein 29 & online (livestream link)
PhD candidate
M. Dong
Dissertation
Aggregate size matters: The impact of soil aggregation on microbial community assembly and suppression of tomato Ralstonia disease
PhD supervisor(s)
prof. dr. G.A. Kowalchuk
prof. dr. E.E. Kuramae
More information
Full text via Utrecht University Repository