Fig. 7. Total soil (A) C and (B) N in the upper 30 cm in December 2004, at the end of the field station trial. NT = no-tillage; ST = standard tillage; CC = continuous cropping; and F = fallow. Data are means ± SE. Means followed by the same letter are not significantly different at the P < 0.05 level. Uppercase letters compare treatments in the top 0- to 30-cm layer; lowercase letters compare treatments for each depth.