Abstract:
The aim of research was to compare soil biological properties under three fertilization systems in crop rotation..
The objective was to evaluate the impact of organic fertilizers in crop rotation on enzymatic activities representative of
some steps of biogeochemical nutrient cycles: C(invertase), N(urease), P(phosphatase), and general microbial activity
(basal soil respiration, ammonification capacity, dehydrogenase activity) in comparison to mineral and mixed
fertilization. It was shown, the majority of biochemical parameters studied was reduced in soil under mixture
vetch+oats followed sunflower in crop rotation, though the tendencies of change were similar. The enzyme activities
were expressed per unit of soil organic carbon and it didn’t change the previous conclusion: the urease and phosphatase
activities increased, but the invertase activity reduced in soil fertilized by manure in comparison to NPK amendment.
Soil basal respiration at field under sunflower was significantly lower (P<0,05) in soil amended by manure in
comparison to one fertilized by NPK. Nitrogen mineralization capacity (ammonification) values were highly variable
and do not allowed to reveal significant differences among treatments. Soil dehydrogenase activities of soil samples
under both studied crops have shown the lower values at mineral fertilization. Our data confirm the assertion that the
organic farming has the favorable impact on the chernozem soil biological properties
