The activitiesof soil enzymes specifically relatedto thecyclesof C,N,
and P responded differentially to the rates of N mineral fertilization
applied along with green manure. The ambiguous tendency of the Ncycle enzymes activity as affected by the N fertilization treatment
indicated that these enzymes were not a useful indicator of soil mineral
N fertilization in the experiment. The enzymes of C and P cycle seem to
be more suitable in this regard because clear tendencies in their activity
was observed in respect to increasing N fertilization rates