Location: Integrated Cropping Systems ResearchTitle: Rhizosphere microbial communities explain positive effects of diverse crop rotations on maize and soybean performance
Submitted to: Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2021
Publication Date: 8/1/2021
Citation: Benitez, M., Ewing, P.M., Osborne, S.L., Lehman, R.M. 2021. Rhizosphere microbial communities explain positive effects of diverse crop rotations on maize and soybean performance. Soil Biology and Biochemistry. Article 108309. https://doi.org/10.1016/j.soilbio.2021.108309.
Interpretive Summary: Crop production systems may include annual rotation of different crops. Crop rotational frequently provides benefits in terms of increased crop yields, reduced input requirements, and resistance to pest and pathogens. However, the mechanisms producing these benefits from crop rotation are not well known. Soil microorganisms perform essential functions that enable crop production and are also influenced by crop rotation practices. In this study, we evaluated changes in soil-plant microbiomes due to crop rotation and crop sequencing. We further correlated changes in these microbiomes to measures of corn and soybean crop performance within different crop rotations. We found increasing crop rotational diversity had positive effects on corn and soybean plant vigor and grain yields, and these benefits could be linked to changes in the soil-plant microbiomes. In some cases, crop sequencing had an additional influence on the performance of the succeeding crop. Combining our results, we found a two-year, corn-soybean crop rotation perpetuated soil-plant microbiomes that contained more potential plant pathogens and produced lower yields compared to four-year crop rotations. Crop production tactics including crop rotation can be used to modify plant-soil microbiomes to produce favorable outcomes in terms of crop performance.
Technical Abstract: In agricultural systems, crop rotation diversity influences soil microbial communities and often increases crop productivity. Yet the specific contributions of microorganisms to crop rotation benefits are unknown. We studied corn (Zea mays L.) and soybean (Glycine max L.) within a two-year corn-soybean rotation and four, four-year, four-crop rotations with varying crop sequences. We hypothesized that rhizosphere microbial communities would predict crop productivity contingent on rotation diversity and previous crop legacy. Sampling at seedling and flowering stages, we assessed rhizosphere bacterial and fungal communities, plant tissue nutrients, aboveground biomass, and yield. Rhizosphere communities varied with rotation diversity and previous crop legacy. Concurrently, corn and soybean yield and biomasses were larger in more diverse rotations and with different crop legacies, but not tissue nutrients. Fungal communities predicted the suppression of corn seedlings when following soybean, and soybean seedlings when following corn, independently of rotation effects. This fungal effect ultimately predicted suppressed corn yield in the corn-soybean rotation, while in more diverse rotations, bacterial communities predicted corn would fully recover from a soybean legacy by flowering. These results suggest that corn-soybean rotations select for yield-suppressive microbial communities and highlight a microbial mechanism behind the benefits of diverse rotations.