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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Livestock, Forage and Pasture Management Research Unit » Research » Publications at this Location » Publication #390459

Research Project: Integrated Agroecosystem Research to Enhance Forage and Food Production in the Southern Great Plains

Location: Livestock, Forage and Pasture Management Research Unit

Title: Temporal dynamics of bacterial communities along a gradient of disturbance in a U.S. Southern Plains agroecosystem

item CORNELL, CAROLYN - University Of Oklahoma
item ZHANG, YA - University Of Oklahoma
item NING, DALIANG - University Of Oklahoma
item WU, LIYOU - University Of Oklahoma
item Wagle, Pradeep
item STEINER, JEAN - Kansas State University
item XIAO, XIANGMING - University Of Oklahoma
item ZHOU, JIZHONG - University Of Oklahoma

Submitted to: mSphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2022
Publication Date: 4/14/2022
Citation: Cornell, C., Zhang, Y., Ning, D., Wu, L., Wagle, P., Steiner, J., Xiao, X., Zhou, J. 2022. Temporal dynamics of bacterial communities along a gradient of disturbance in a U.S. Southern Plains agroecosystem. mSphere. 6. Article e01160-20.

Interpretive Summary: Environments in agroecosystems are continually modified due to land use and management practices that can directly and indirectly influence soil bacterial communities. In addition, soil communities are exposed to variability in space and time, raising the need for continued research on a range of agricultural systems. This study investigated the effects of land use and sampling time on the structural and functional diversity of bacterial communities as well as the interactions with soil and environmental factors in four land uses [native tallgrass prairie, introduced (old world bluestem) pasture, no-tillage (NT) canola, and conventional tillage (CT) wheat] in the U.S. Southern Plains. Results indicated that land use, especially with intensive management, had the greatest impact on taxonomic diversity, while sampling time within a specific land use was more important for differences observed in functional diversity. Soil nutrients, especially nitrogen, and soil water content were determined to be critical for variations in community taxonomic and functional diversity across land management and sampling time. Functional diversity was also reduced under intensive management. Results suggest that preserving microbial diversity should be one of the main focuses of sustainable agriculture, and soil disturbance should be minimized in intensively managed agricultural land.

Technical Abstract: Land use conversion for intensive agriculture leads to unfavorable changes to soil ecosystems causing global concern. As soil bacterial communities mediate essential processes that maintain the functions of terrestrial ecosystems, understanding their responses to environmental perturbations is a major goal of agricultural research. In this study, we integrated a study of temporal dynamics of soil bacterial community diversity over a one-year period with that of different disturbance intensities across a U.S. Southern plains agroecosystem, including a native tallgrass prairie, introduced (old world bluestem) pasture, no-tillage (NT) canola, and conventional tillage (CT) wheat. Land use had a greater impact than season on bacterial taxonomical diversity, whereas sampling time and its interaction with land use was central to the differences in functional diversity. The hierarchy of the main drivers of taxonomical diversity were tillage > sampling time > temperature. Functional diversity had a similar amount of variation explained by all measured soil and climatic factors. Sampling time had the strongest correlation with total nitrogen > rainfall > nitrate. Within individual land uses, community variations for CT wheat were mostly attributed to nitrogen levels compared to community variations in NT canola were mainly explained by soil organic matter and soil water content. In comparison, grasslands had a relative equal amount of bacterial community variation explained by all measured factors. Lastly, when comparing community composition and function, functional diversity had a stronger relationship with taxonomic diversity for CT wheat compared to phylogenetic diversity in the prairie. These findings reinforce that tillage management has the greatest impact on both taxonomic and functional diversity of soil bacterial communities with sampling time also critical. Hence, our study highlights the importance of the interaction between temporal dynamics and land use in influencing bacterial community diversity and provides additional support for reducing soil disturbance in intensively managed agricultural land uses to conserve soil biodiversity.