Different responses of soil carbon chemistry to fertilization regimes in the paddy soil and upland soil were mainly reflected by the opposite shifts of OCH and alkyl C

The supposition that cropping system might affect fertilization-induced changes in chemical composition of soil organic carbon (SOC) and microbial community has mostly derived from field experiments different sites, which may have been disturbed by climate conditions parent materials. Here, two adjacent long-term were used, contained similar four fertilization regimes NPK, 2NPK, NPKOM, an unamended control (Control), while contrasting annual rice–rice maize–maize, to investigate how SOC chemistry differ paddy upland soil, whether they correlate with bacterial taxa. the was mainly determined NO3–-N total N, explained SOC. NPKOM treatments increased CCH3, decreased OCH, reduced CH/CH2, those raised respectively, indicating opposite shifts OCH alkyl C (i.e., CCH3 CH/CH2) each paired fertilizer treatment soils. In NPK showed no association any taxa, 2NPK a negative NO3–-related species, CH/CH2 Proteobacteria Bacteroidetes. negatively associated Thermogemmatisporales Acidobacteriaceae subgroup 1, positively Thermogemmatisporales, copiotrophic Our results provided direct evidence mediated shift direction specific functional group under regimes, implied completely can likely be attributed resulting N change soil.