Pea-Wheat Rotation Affects Soil Microbiota Diversity, Community Structure, and Soilborne Pathogens

Area of Science:

• Agricultural Science
• Soil Microbiology
• Ecology

Background:

• Intensive monocultures negatively impact ecosystem function.
• Sustainable agriculture requires alternative methods like crop rotation.
• The effects of pulse crops, common in Canadian prairies, on soil microorganisms are understudied.

Purpose of the Study:

• To investigate the impact of different crop rotations (pea, wheat, pea-wheat) and fallow on soil bacterial and fungal communities.
• To analyze changes in microbial diversity and composition.
• To assess the influence of crop management on specific microbial groups.

Main Methods:

• High-throughput sequencing of 16S and 18S rRNA genes for bacterial and eukaryotic communities.
• Analysis of bulk soil samples from Canadian prairies under different crop treatments.
• Comparative analysis of microbial richness, diversity, and community composition.

Main Results:

• Crop rotations and fallow significantly altered soil microbial community composition and diversity.
• Pea monoculture drastically reduced bacterial and fungal richness and diversity compared to wheat, pea-wheat rotation, and fallow.
• Pea-wheat rotation led to an increased abundance of *Fusarium graminearum*.
• Bacterial communities showed less response to crop rotation identity than fungal communities.
• Fungal microbiota exhibited shifts, with Actinobacteria increasing in fallow and Firmicutes in wheat.

Conclusions:

• Crop rotations demonstrably alter soil microbial community diversity and composition in the Canadian prairies.
• The extensive use of pea in rotation with wheat requires careful consideration of its ecological impacts.
• Balancing nitrogen mineralization, water conservation, and the effects on beneficial and pathotrophic fungi is crucial for sustainable prairie agriculture.