Figure 3

Effect of EOM on soil pH, and the plots were labeled without pig manure (without), with pig manure (with). The data were expressed by mean ± standard error (n = 3). Pig manure × Treatment: interaction between crop residues without and with pig manure. The different lowercase and uppercase letters denote the significant difference among different treatments without and with pig manure addition at 0.05 level, respectively. The two-way ANOVA results were indicated by NS non-significant, *p < 0.05, **p < 0.01, ***p < 0.001.