Table 2 Basic physicochemical properties of paddy soil under fertilization regimes at different soil depths (mean± SE, n=3). CK: no fertilizer; NPK: chemical fertilizers; ST: rice straw combined with chemical fertilizers; OM: 70% NPK + 30% chicken manure; SOC: soil organic content; MBC: microbial biomass carbon; MBN: microbial biomass nitrogen. Statistical significances based on one-way analysis of variance and Duncan’s test (P < 0.05). Different lower-case letters represent significant differences in soil property between soil depths within a fertilization regime. Different uppercase letters represent significant differences in a soil property between fertilization regimes within a soil depth.