Effects of residue placement and crop type on soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), potential C and N mineralization (PCM and PNM), microbial biomass C and N (MBC and MBN), and NH₄-N and NO₃-N concentrations in the greenhouse.

Soil samples were collected at the 0–20 cm depth in the field and used for the greenhouse experiment. *Significant at P = 0.05. **Significant at P = 0.01. aNumbers followed by different letters within a column in a set are significantly different at P≤0.05 by the least square means test. bCoefficient of variation. cNot significant.