Soil microbial communities in the face of changing farming practices: A case study in an agricultural landscape in France

Laurie Dunn,Sébastien Terrat,Luc Biju-Duval,Nicolas Chemidlin Prévost-Bouré,Christophe Lang,Nicolas Marilleau,Solène Perrin,Mélanie Lelièvre,Tanvir Shahzad

doi:10.1371/journal.pone.0252216

Abstract

According to biogeography studies, the abundance and richness of soil microorganisms vary across multiple spatial scales according to soil properties and farming practices. However, soil microorganisms also exhibit poorly understood temporal variations. This study aimed at better understanding how soil microbial communities respond to changes in farming practices at a landscape scale over time. A regular grid of 269 sites was set up across a 1,200 ha farming landscape, and soil samples were characterized for their molecular microbial biomass and bacterial richness at two dates (2011 and 2016). A mapping approach highlighted that spatial microbial patterns were stable over time, while abundance and richness levels were modified. The drivers of these changes were investigated though a PLS-PM (partial least square path-modeling) approach. Soil properties were stable over time, but farming practices changed. Molecular microbial biomass was mainly driven by soil resources, whereas bacterial richness depended on both farming practices and ecological parameters. Previous-crop and management effects and a temporal dependence of the microbial community on the historical farming management were also highlighted.

Highlights

The sustainable use of soils is of key importance in the current context of climate change and of a growing worldwide population
This study shows that the evolution of soil microbial communities depends on both soil properties and farming practices
Previous-crop effects and the historical farming management were identified as determining factors for a better understanding of soil microbial variations at the landscape scale

Summary

Introduction

The sustainable use of soils is of key importance in the current context of climate change and of a growing worldwide population. This goal may be reached by preserving soil biodiversity through agroecological practices like reduced tillage, lower chemical inputs or diversification of plant species in crop rotations [1]. Soil microorganisms play a crucial role within this biodiversity. This is especially true in agro-ecosystems, where their abundance (up to 1 billion cells per gram of soil) and diversity (up to 1 million species per gram of soil) [2], are highly involved in soil fertility and stability: they support plant productivity, determine nutrient and water cycling, the soil structural stability, and plant health [3]. Understanding how soil microorganisms face changes in farming practices across space and over time is a challenge within the framework of a sustainable agriculture.

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