Figure 3. Changes in soil properties as reflected in top soil organic matter (SOM, 0–20 cm) (a) and mineral elements contents before and after earthworm digested compost (b).

AK, content of total available potassium (g kg⁻¹); AP, rapidly available phosphorus (g kg⁻¹); TP, content of total phosphorus (%); TK, content of total potassium (%); TN, total nitrogen (%). The different footnote symbols represent significant difference (DUNCAN test, **extremely striking contrast (P < 0.01); *significant difference (P < 0.05)). Same letter(s) means no significant difference (P < 0.05), lower-case for chemical farming (CF) and upper-case for Biodiversity Management of Organic Farming (BMOF).