Effects of nitrogen enrichment on soil microbial characteristics: From biomass to enzyme activities

•1248 data series were collected to study response of soil microbes to N enrichment.•Thresholds effect of N enrichment on the response of MBC and MBN were observed.•Response of soil microbes depended on the biome types, N rates and types, etc.•The effect of N enrichment on soil microbes relate with changes in soil property.