Wheat rhizosphere effect on soil microbial structure and activities change with pedoclimatic conditions in Moroccan agroecosystems

Abstract Crop may select their microbiome by modifying soil physicochemical properties. However, the variation of this crop capability throughout variable agroclimatic conditions remain underexplored. This study examines how wheat growth affects soil microbiota structure and activities under contrasting Moroccan agroclimatic conditions qualified as unfavorable, moderate and favorable based on their mean annual temperature (MAT) and mean annual precipitation (MAP). For this purpose, microbial biomass, structure and catabolic activities were analyzed in rhizosphere and bulk soils sampled in wheat fields located in Safi (unfavorable), El-Jadida (moderate), Meknes and Beni-Mellal (favorable) regions. The results indicated that microbial structure varied between regions and was driven by soil edaphic properties and climatic variables (MAP, MAT, altitude) in bulk soils. In rhizosphere soils, the impact of climatic parameters was considerably reduced and physicochemical factors were the main drivers of microbial structure. Interestingly, we observed a higher soil catabolic activities in the rhizosphere than bulk soil of wheat only in Safi. Our study demonstrates that the wheat functional-based selection on soil microbiota is modulated through a modification of soil edaphic properties which balance the effect of climatic conditions and suggests a greater wheat potential to select catabolically active microbes in its rhizosphere when cultivated in unfavorable conditions.