Agricultural soils play a vital role in providing human society with food and water security, climate change, nutrient cycling, disease regulation and more. This is only possible through physical and chemical transformations performed by soil fauna and microorganisms, such as fungi, protists, bacteria and archaea. Understanding how the biodiversity and functions provided by these microorganisms are impacted by agricultural management is therefore an issue of global concern.
As part of the German ‘Monitoring of Biodiversity in Agricultural Landscapes’ MonViA, the Thünen Insitute of Biodiversity soil microbiology lab has optimised methods for the effective monitoring of soil microbial communities. They established the first high-frequency monitoring within two-week intervals of contrasting soil types and agricultural management practices over two years, in neighbouring fields located in Northern Germany. This high-frequency monitoring was a necessary first-step in understanding whether observed changes in microbial biodiversity are a consequence of human-driven forces or background natural variation driven by seasonality or inherent soil physico-chemical characteristics.
For example, fungal biodiversity and abundances of bacterial nitrogen cycling genes were strongly tied to seasonality, whereas protists were indicators of intensive practices such as tillage. Specific protists, namely Cercozoa, were also found to be important predators of bacteria and archaea by preferentially feeding on actively growing cells suggesting that tillage may have broader negative consequences for soil and therefore plant nutrient cycling by hindering microbial predator-prey interactions.
Current research seeks to apply these principles to over 300 arable soils collected across Germany, in collaboration with the German Agricultural Soil Inventory coordinated by the Thünen Insitute of Climate-Smart Agriculture. Specifically, microbial indicators associated with desirable soil functions will be identified in the context of agricultural management practices that either promote or inhibit them.
Links to the publications:
Finn et al., 2023. Importance of sample pre-treatments for the DNA-based characterization of microbiomes in cropland and forest soils. Soil Biology and Biochemistry 184, 109077. https://doi.org/10.1016/j.soilbio.2023.109077
Wang et al. 2025a. Distinct seasonal and annual variability of prokaryotes, fungi and protists in cropland soil under different tillage systems and soil texture. Soil Biology and Biochemistry 203, 109732. https://doi.org/10.1016/j.soilbio.2025.109732
Wang et al., 2025b. Implications of size-dependent predation of protists and nematodes on the composition and functionality of the prokaryotic soil microbiome. Applied Soil Ecology 212, 106201. https://doi.org/10.1016/j.apsoil.2025.106201
Yang et al., 2025. Seasonal dynamics of prokaryotic nitrogen cycling genes in cropland soils: effects of soil texture, tillage and environmental factor. Soil and Tillage Research 253, 106694. https://doi.org/10.1016/j.still.2025.106694