Effects of residue placement and crop type on crop shoot (grains+leaves+stems) and root biomass C and N contents in the greenhouse.

*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. bNon-measurable values due to negligible amount of root biomass. cCoefficient of variation. dNot significant.