Data for TN above and below straw layers were subjected
to two-way ANOVAs, respectively. Data for free N and immobilized
N were subjected to on-way ANOVAs. Before analysis, data
were log10-transformed to meet the assumptions of normality and
homogeneity of variance. When ANOVAs were significant, means
were compared by Duncan’s multiple range tests at the 0.05 confidence
level. All data analyses were performed using SPSS 16.00