Impacts of cover crop residue management on the arbuscular mycorrhizal fungal communities of maize. root metagenome

Objective: Maintaining better host crops for arbuscular mycorrhizal fungi (AMF) in cover crop rotational systems can be important because having active AMF propagules present in the soil can allow for rapid colonization, better crop growth, and nutrient uptake. However, there is little information regarding the effects of different cover crops on AMF communities in subsequent maize (Zea mays L.) roots. Thus, we evaluated the molecular diversity of AMF community structure in the roots through the 2-year rotation using amplicon sequencing of the Illumina Miseq Platform. Methods: Three different cover crop-maize rotational systems were established including winter wheat, hairy vetch, and brown mustard with or without incorporation of cover crop residue. We examined AMF colonization and communities in maize roots at the V6 stage. Results: The AMF root colonization in the maize was significantly influenced by cover crop treatments. However, the AMF communities in roots with or without residue incorporation did not differ. Although the AMF communities colonizing maize roots were not influenced by cover crop residue management, the AMF communities were significantly changed by cover crop type. Conclusion: Our results indicated that cover cropping rather than the incorporation of cover crop residues may be a key factor for shaping the AMF communities in maize roots. Thus, further investigation into the functional aspects of AMF communities in cover crop management will provide useful information on the role of AMF to improve crop productivity in cover crop rotational systems.