Limited resilience of the soil microbiome to mechanical compaction within four growing seasons of agricultural management

Manon Longepierre,Tino Colombi,Johan Six,Thomas Keller,Franco Widmer,Peter Weisskopf,Martin Hartmann

doi:10.1038/s43705-021-00046-8

Manon Longepierre, Tino Colombi + Show 5 more

Open Access

https://doi.org/10.1038/s43705-021-00046-8

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Abstract

Soil compaction affects many soil functions, but we have little information on the resistance and resilience of soil microorganisms to this disturbance. Here, we present data on the response of soil microbial diversity to a single compaction event and its temporal evolution under different agricultural management systems during four growing seasons. Crop yield was reduced (up to −90%) in the first two seasons after compaction, but mostly recovered in subsequent seasons. Soil compaction increased soil bulk density (+15%), and decreased air permeability (−94%) and gas diffusion (−59%), and those properties did not fully recover within four growing seasons. Soil compaction induced cropping system-dependent shifts in microbial community structures with little resilience over the four growing seasons. Microbial taxa sensitive to soil compaction were detected in all major phyla. Overall, anaerobic prokaryotes and saprotrophic fungi increased in compacted soils, whereas aerobic prokaryotes and plant-associated fungi were mostly negatively affected. Most measured properties showed large spatial variability across the replicated blocks, demonstrating the dependence of compaction effects on initial conditions. This study demonstrates that soil compaction is a disturbance that can have long-lasting effects on soil properties and soil microorganisms, but those effects are not necessarily aligned with changes in crop yield.

Highlights

Modern agriculture depends on a high level of mechanization to efficiently and economically manage cropping systems
Change in yields for permanent ley (PL) and arable crops in the rotations were presented as percent change in comparison to (a) PL in the uncompacted control or (b) the respective crop in the uncompacted control under conventional tillage (CT), respectively
For the arable crop in the rotation, the significant differences in yield over all blocks between the control and the compaction treatments, as well as the tillage effect within each year were assessed with ANOVA using the aov function in R since the homogeneity of variance and normal distribution of the residuals were supported

Summary

Introduction

Modern agriculture depends on a high level of mechanization to efficiently and economically manage cropping systems. It can take decades for the soil to recover [2] without appropriate management [3]. Soil compaction adversely affects soil structure by increasing bulk density and soil mechanical resistance, as well as reducing macroporosity and pore connectivity [6, 7]. The largest impact of compaction on soil organisms likely occur in the topsoil, since this is where most of the root biomass [12] and microbial biomass and diversity [13] are contained, and represents the preferred habitat for most of the soil fauna, such as earthworms [14] and collembola [15]. Topsoil is most likely the most sensitive layer to measure both the initial impact and first signs of resilience after a compaction event

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