Rhizosphere Processes and Microbial Functions under Successive Wheat Rotational Positions

Wheat is an important staple crop worldwide, and the increasing demand for wheat requires more intensive cropping systems, such as monoculture. However, continuous cultivation of wheat contributes to a decline in grain yield and quality, possibly due to increased weed infestation and the proliferation of pests and fungal pathogens. Therefore, in the present study, we aimed to investigate 1) the underlying mechanisms that govern the productivity of winter wheat (WW) grown in self-succession as opposed to WW grown after a break crop, oilseed rape, 2) the impact of successive wheat cultivation on glucose release from roots and microbial activity, 3) the effects of continuous wheat rotations on glucose release, microbial growth and activity, and expression of sugar transporter genes. We found that the position of WW in the rotation has a significant impact on wheat biomass and also the structure and function of the soil microbiota. The findings underscore the necessity of identifying and characterizing specific compounds in root exudates that trigger soil microorganisms. The study revealed that regions characterized by high glucose release in wheat roots exhibited heightened microbial activity, indicating a direct correlation between glucose availability and microbial stimulation. Moreover, total microbial biomass experienced a decline in both the rhizosphere and bulk soils of W3 relative to W1, indicating shifts in the microbial community composition. This study emphasizes the importance of long-term research into the effects of continuous wheat cultivation on soil health and microbial communities. Enhancing beneficial microorganisms in the rhizosphere is crucial for sustainable agriculture and continued exploration of innovative tools like the glucose imaging method offer new opportunities for soil research, helping us monitor root exudation and microbial responses in field settings.