Integrating perennial bahiagrass into the conventional rotation of cotton and peanut enhances interactions between microbial and nematode communities

Authors: ZHANG, KAILE - University Of Florida; Schumacher, Lesley; MALTAIS-LANDRY, GABRIEL - University Of Florida; GRABAU, ZANE - University Of Florida; GEORGE, SHEEJA - University Of Florida; WRIGHT, DAVID - University Of Florida; SMALL, IAN - University Of Florida; LIAO, HUI-LING - University Of Florida

Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2021
Publication Date: 10/18/2021
Publication URL: https://handle.nal.usda.gov/10113/7546382
Citation: Zhang, K., Schumacher, L.A., Maltais-Landry, G., Grabau, Z., George, S., Wright, D., Small, I., Liao, H. 2021. Integrating perennial bahiagrass into the conventional rotation of cotton and peanut enhances interactions between microbial and nematode communities. Applied Soil Ecology. 170(2022). Article 104254. https://doi.org/10.1016/j.apsoil.2021.104254.
DOI: https://doi.org/10.1016/j.apsoil.2021.104254

Interpretive Summary: Crop rotation is an important management tool for farmers, especially those suffering yield losses due to pests and pathogens. Assessing the performance of crop rotation can be done, in part, by analyzing the nematode (microscopic worm) community as well as soil microbes (bacteria and fungi). Determining if crop rotations that include bahiagrass affect the soil community of bacteria, fungi, and nematodes may improve the movement of nutrients from the environment through these communities and back to the environment. The rotation that included bahiagrass did not affect the diversity of bacteria in the soil community, but it did shift the nematode community from being dominated by types that feed primarily on plant roots to a community that included both plant feeders and bacterial feeders. The additional information about soil food webs adds to our scientific knowledge and serves as a foundation that scientists can build on to develop better crop rotation systems.

Technical Abstract: Integrating two years of bahiagrass (Paspalum notatum) into peanut (Arachis hypogea L.) and cotton (Gossypium hirsutum L.) cropping systems improves soil quality and crop production as compared to a peanut-cotton-cotton rotation (CR). However, it is unclear if this system, known as a sod-based rotation (SBR), affects biotic interactions among soil organisms and whether such biotic interactions affect nutrient cycling. Before crop planting (April 2017), soils were collected from cotton plots located in Quincy, FL, USA that had been under CR and SBR for 17 years. We used amplicon sequencing to investigate soil microbial communities and an inverted microscope technique to quantify nematodes. Compared to CR, SBR increased nematode alpha diversity measured by the Shannon index and resulted in different nematode communities based on a nonmetric multidimensional scaling ordination. In contrast, SBR induced no variation in the bacterial community diversity and structure relative to CR. Acidobacteria, Actinobacteria, Bacteroidetes, Proteobacteria, and Nitrospira dominated the bacterial community in both crop rotations. SBR plots were significantly enriched in Nitrospora, while the second year of cotton in CR had a higher relative abundance of Alphaproteobacteria. Nematode communities were primarily dominated by plant-parasitic nematodes and bacterial-feeding nematodes in SBR, while plant-parasitic nematodes were predominant in CR. In addition, there were more linear correlations between the bacterial and nematode communities in SBR. Overall, these results suggest that integrating bahiagrass in CR fostered robust soil food webs and complex soil trophic interactions, with potential benefits for C and nutrient transformations as well as stress tolerance to plant pathogens.