Figure 4

Density of nematodes from four trophic groups among the three cropping systems, by depth (CT = conventional, tilled, NT = no-till and ORG = organic, tilled), according to morphological analysis. Bars represent mean values ( ± s.e.m., n = 8) for each cropping system by depth combination. Within a trophic group, bars that share the same lower-case letters are not statistically different from each other (ANOVA, significant system, depth, system, and/or system×depth effects, P < 0.01; Tukey-Kramer test).