Soil biogeography at the habitats of origin of major crops

Abstract

The rewilding of modern agriculture is challenged by our current uncertainties on the microbiome of major crop wild progenitors (CWPs). Here, we conducted the first global standardised field survey to investigate the edaphoclimatic conditions and soil microbiome of 125 wild populations associated with 10 of the most important CWPs at their centres of origin. The wild populations clustered into four ecoregions, ranging from deserts to tropical seasonal forests and savannas, shaped by two edaphoclimatic dimensions that distinguished areas with high soil sand contents and scarce micronutrients from the more fertile ecoregions characterised by variations in aridity, soil pH and carbon storage potential. We identified a common soil core microbiome with differentiated assemblages across ecoregions, driven by varying environmental preferences among soil biodiversity kingdoms, which reflects potential shifts in their functional profiles. The CWPs created unique microhabitats within ecoregions that strongly influenced the soil community assembly, indicating specific co-evolutionary interactions. These insights into the evolutionary origins of domesticated crops hold the potential to advance microbial-assisted breeding and microbiome rewilding of croplands across the globe.

The abundant fraction of soil microbiomes regulates the rhizosphere function in crop wild progenitors

“…60% of the cultivated area globally (FAOSTAT, 2023). We conducted a comprehensive sampling of rhizosphere and bulk soils from 110 wild populations along the geographic distributions of these nine CWPs, including ecologically broad edaphoclimatic gradients that span deserts to tropical seasonal forests and savannas (Fernández-Alonso et al, 2023) (Figure 1). We studied four microbial groups: bacteria, fungi, protist and invertebrate communities and measured 20 soil metrics including soil organic carbon content, nutrient cycling, pathogen control, plant-soil mutualisms and organic matter degradation.…”