Inspite of working with a
clayey neutral soil which shielded the microbes from a
more direct and extensive contact, some apparent
interactions could still be deduced from the results
obtained from the metal treatments. Inhibition of soil
microbial activities by a combination of Cu and Zn was
greater at lower metal concentration than the effect of
each metal separately at double the concentration. In
the effect of treatment on respiration of soil microbes,
for instance, (Table 7) the rate of inhibition in the Cu
and Zn amended soils were 1.08 and 1.61 (