Table 2 Correlation coefficients between TN and its fractions.

From: The influence of a year-round tillage and residue management model on soil N fractions in a wheat-maize cropping system in central China

Parameter TN PON MBN WEON Mineral N
TN 1     
PON 0.964** 1    
MBN 0.989** 0.968** 1   
WEON 0.956** 0.945** 0.976** 1  
Mineral N 0.607** 0.545* 0.535* 0.478* 1
  1. TN: soil total nitrogen, PON: particulate organic nitrogen, MBN: microbial biomass nitrogen, WEON: water-extractable organic nitrogen. **Significant at P < 0.01, *Significant at P < 0.05.