Ecological impact of conventional, organic and biodynamic viticultural systems and associated practices on soil microbiota in different French territories

Abstract

Organic (OV) and biodynamic (BD) production systems have developed substantially as alternatives to conventional systems (CV) to increase the sustainability of viticulture. However, their impact on the biological quality of soil is still poorly documented. Here, we characterised different soil microbiota parameters in a network of 152 vineyard plots using molecular tools based on soil DNA characterisation. The plots were equally distributed in three French viticultural territories (Alsace, northern Burgundy, southern Burgundy) and selected to balance the relative share of each production system (1/3 of CV, OV and BD). Data on soil management practices such as soil tillage, inter-row plant cover and fertilisation were also collected for each plot to explore their impact on the soil microbiota. More intensive soil tillage, sparse inter-row plant cover, and the export of vine shoots frequently observed in northern Burgundy plots partly explained the reduction of ∼50 % of molecular microbial biomass, ∼15 % of microbial diversity and ∼90 % of microbial interactions compared to the soils sampled in Alsace. Variance partitioning of the cumulated microbial dataset showed higher microbial biomass and bacterial richness in OV than in CV and in BD than in OV. The complexity of microbial interactions networks increased by about 145 % in BD compared to CV and decreased by about 37 % in OV compared to CV. Our findings suggest that while OV and BD systems can enhance soil microbiota quality, their benefits could be further optimized through improved cover cropping and reduced tillage.