Changes in microbial physiology and carbon-use efficiency upon improving soil habitat conditions in conservation farming systems

作者：Christoph Rosinger, Gernot Bodner, Valentina Forer, Hans Sandén, Thomas Weninger, Anna Zeiser, Axel Mentler, Katharina Keiblinger · 发表于：Agriculture Ecosystems & Environment · 年份：2024 · DOI：10.1016/j.agee.2024.109246 · 被引用次数：27 · 研究领域：Soil Carbon and Nitrogen Dynamics、Agriculture, Soil, Plant Science、Peatlands and Wetlands Ecology

The interplay between soil microbial anabolism and metabolism has recently been postulated as an important lever for carbon sequestration in soils. Theoretical considerations suggest that high microbial growth rates and a high carbon-use efficiency (CUE) are associated with increased soil organic carbon (SOC) build-up in arable soils. Nature-oriented conservation agricultural practices are believed to facilitate this microbial-driven process of SOC accrual; a practical validation of this postulation is however missing. Against this background, we evaluated the effect of agricultural management and site-specific soil chemical and physical properties on microbial physiology (i.e., respiration, bacterial and fungal growth rates, and microbial biomass turnover) and CUE by an on-farm comparison of conventional farming, conservation farming and unmanaged reference soil systems (i.e., adjacent field margins) at twenty-one sites across three soil depths. We show that a change in agricultural management towards soil health regeneration has a significant impact on microbial physiology. Bacterial growth, respiration and microbial biomass turnover increased from conventional farming towards conservation farming systems to reference soils. The opposite trend however was found for fungal growth and microbial CUE, with highest values observed in conventional farming systems. This clearly contradicts the prevailing idea that higher microbial CUE in conservation farming systems may be associa...