Soil  metagenome
The tested soil was purple soil with clay loam texture, collected from the 0-20 cm soil layer of farmland in Daguan Town, Nanchuan District, Chongqing. Soil samples were transported to the greenhouse of the College of Resources and Environment, Southwest University, air-dried, and then impurities such as plant residues and stones were removed. The soil was sieved through a 5 mm sieve, mixed uniformly, and potted for use, with each pot containing 4.5 kg of dry soil.