title: missing
design: The microbial analysis was conducted using high-throughput 16S rRNA pyrosequencing (Yang et al., 2018b), DNA was extracted using the E.Z.N.A. soil DNA Kit (Omega Bio-tek, Norcross, GA, U.S.), the bacterial 16S rRNA genes were amplified using the universal bacterial primers 27F (5-AGRGTTYGATYMTGGCTCAG-3) and 1492R (5-RGYTACCTTGTTACGACTT-3), the archaea 16S rRNA genes were amplified using the primers 349F (CCCTACACGACGCTCTTCCGATCTN (barcode) GYGCASCAGKCG MGAAW) and 806R (GACTGGAGTTCCTTGGCACCCGAGAATTCCAGGACTACV SGGGTATCTAAT). Detailed DNA extraction, purification and quantification methods was shown in the Supporting Information.