Use of catch crops as green manures significantly increased soil
enzyme activities during the growing period of following main crops.
Such biologicalimpactsof FP andORappearedto besimilar andtherefore
they both were suitable for increasing the biological activity of soil as
evaluated by enzymatic activities. As different tendencies were shown
for the soil studied chemical properties as influenced by the catch crop
treatments, it is not possible to make any conclusive statements on
their status within the three experimental years.
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.
Since enzyme activities are considered important components of the
biological activity of soil, catch crops along with moderate mineral N
fertilization management can be recommended as ameansof promoting
this component of the above-mentioned activity, which is so critical to
soil fertility and productivity.