Bacterial and archaeal 16S rRNA and fungal ITS sequences after cover cropping in long-term corn monocultures with and without N fertilization

This study sought to identify microbial indicators of soil health after introducing cover crops to a long-term corn monoculture with and without N fertilization. The study was a 3x2 split-plot arrangement of N rates (0, 202, 268 kg N/ha) and cover crop (ceral rye and hairy vetch mixture) treatments in a randomized complete block design with three replicates sampled in 2019 and 2020. The site was in Monmouth, Illinois, USA. Indicators from this study will serve to compare the soil microbiota across systems and become primary information to assess and optimize cover cropping strategy for sustainable agriculture. Each sample name shows the CC treatment (CC: cover crop; BF: bare fallow), N rate treatment (0, 202, 269 kg N/ha) - plot number - year of the study (2019, 2020). Each sample contains a sequence for each taxa (bac, arc, fun), replicate (R1, R2, R3), and sequence direction (forward, reverse). 2020 samples had two runs. Thus, 2019 samples each contain 18 sequences, and 2020 samples each contain 36 samples, accounting to a total of 972 sequences.

本研究旨在明确在长期单一种植玉米且分别施入与不施氮肥的农田中引入覆盖作物（cover crop）后，表征土壤健康状况的微生物指示物。本研究采用3×2裂区设计（split-plot arrangement），设置氮肥施用量（0、202、268 kg N/ha）与覆盖作物（冬黑麦与毛叶苕子混播）两个处理因素，依托随机完全区组设计（randomized complete block design），于2019年与2020年开展三次重复采样，实验地点位于美国伊利诺伊州蒙茅斯市。本研究所得的微生物指示物可用于对比不同种植体系下的土壤微生物群落（soil microbiota），并为评估与优化可持续农业的覆盖作物种植策略提供核心参考依据。每份样本的命名格式为：覆盖作物处理（CC：覆盖作物；BF：裸休耕）-氮肥施用量处理（0、202、269 kg N/ha）-样地编号-研究年份（2019、2020）。每份样本对应各分类群（细菌（bac）、古菌（arc）、真菌（fun））、重复样（R1、R2、R3）以及测序方向（正向、反向）的序列数据。2020年的样本包含两轮测序，因此2019年每份样本含18条序列，2020年每份样本含36条序列，总计得到972条序列。