High-Resolution Indicators of Soil Microbial Responses to N Fertilization and Cover Cropping in Corn Monocultures

Cover cropping (CC) is the most promising in-field practice to improve soil health and mitigate N losses from fertilizer use. Although microbiota play essential roles in health, their response CC has not been well characterized by bioindicators of high taxonomic resolution within typical agricultural systems. Our objective was fill this knowledge gap with genus-level indicators for corn [Zea mays L.] monocultures three rates (N0, N202, N269; kg ha−1), after introducing a mixture cereal rye [Secale cereale hairy vetch [Vicia villosa Roth.], using winter fallows (BF) as controls. A 3 × 2 split-plot arrangement treatments studied randomized complete block design replicates over two years. Bacterial archaeal 16S rRNA fungal ITS regions were sequenced Illumina MiSeq system. Overall, our high-resolution able represent specific functional or ecological shifts microbial community. The abundances representing acidophiles, nitrifiers, denitrifiers increased fertilization, while those heterotrophic nitrite oxidizers, N0. Introducing decreased nitrate levels up 50% across rates, biomass 73% fertilization. promoted diverse functions niches, including N-fixers, reducers, mycorrhizae, only N-cycling genera associated BF. Thus, can enhance biodiversity simplified systems reduce leaching, but might increase risk nitrous oxide emission without proper nutrient management. This primary information first its kind system provided valuable insights into limits potential strategy health.