design: Metagenomic sequencing libraries were constructed from soil samples subjected to electric treatment and nitrogen fertilization (urea or ammonium sulfate). High-molecular-weight genomic DNA was first extracted using the PowerSoil Pro Kit (QIAGEN) under low-temperature conditions to minimize degradation. The quantity and quality of the extracted DNA were assessed using a Qubit fluorometer and agarose gel electrophoresis. Qualified DNA was then used for library preparation with the Illumina DNA Prep kit, following the manufacturers protocol. This process included enzymatic fragmentation, end repair, adenylation, and ligation of Illumina-compatible adapters with unique dual-index barcodes for sample multiplexing. The final libraries were quantified and their size distribution (typically ~350 bp) was verified using an Agilent 2100 Bioanalyzer High Sensitivity DNA chip. Pooled libraries were sequenced on an Illumina NovaSeq 6000 platform to generate 2150 bp paired-end reads.