Fig. 7. Relationship of the substrate limitation of bacteria with (a) the pH and (b) the dissolved organic carbon (DOC). Each color represents a soil. Hollows represent soils in the 7th day of
incubation, and solids represent soils at the end of the 100th day of incubation. Squares, circles, triangle and diamond mean the control soil, soil amended with 300BC, 500BC, and 700BC,
respectively. Data of substrates limitation was unavailable at the end of the incubation for all treatments of soil S1 as the PLFA 16:1w7 has not been detected.