sequences of soil gene
Soil genomic DNA was extracted using the TIANamp Soil DNA Kit DP336 (TIANGEN BIOTECH (BEIJING) CO., LTD, China). For library preparation, 1 g of DNA was randomly fragmented into ~350 bp fragments using a Covaris LE220R-plus ultrasonicator (Covaris, USA). The entire library preparation is completed through steps including end repair, addition of A-tails, ligation of sequencing adapters, purification, and PCR amplification.