From farm to microbe: organic amendments and soil texture as drivers of soil Microbiome composition

Understanding how agricultural practices affect soil bacterial communities is vital to mitigating the negative impacts of intensive agriculture on soil health and preventing further deterioration of arable land. Increasing pressure on agricultural land necessitates careful management of our productive soil. This study investigates the interaction between organic amendments and soil texture in agricultural soils (n = 93) used for arable production, using a 16S rRNA-sequencing based microbial community analysis. Amendments include slurry, digestate, and farmyard manure. Additionally, soil physicochemical parameters were collected to explore the drivers of patterns of soil microbial diversity.

Microbial community composition was significantly influenced by organic amendments and soil texture, which both exerted distinct selective pressures. Analysis using 16S rRNA-sequencing and advanced modelling identified significant factors affecting community structure, including soil calcium levels, the crop grown one year previously, loss on ignition (LOI), and farm ID. The genus Candidatus Nitrosotalea was found to be positively associated with application of farmyard manure, while genus AD3 (phyla Chloroflexi) was found to be negatively associated with application of digestate and slurry.

The results highlight the importance of considering multiple, interacting factors when trying to establish how agricultural practice affects soil microbial communities. Our findings underscore the need for tailored management strategies - specific to the local environment and available resources - to promote soil health.