Applied organic manure and chemical fertilizer can greatly alter
soil enzymatic activity. Dick (1988) indicated that long-term application
of organic manure increases soil enzymatic activity, but
NH4
+-N fertilizer causes a decrease of amidase and urease activities
related toNfertilizer cycle. Masciandaro et al. (1997) indicated that
soil dehydrogenase activity is increased after vermicompost was
applied to soils at a rate of 90 t/ha. Arancon et al. (2006) showed that
vermicompost also increases soil dehydrogenase activity. Marinari
et al. (2000) showed that a higher level of dehydrogenase activity
was observed in soil treated with vermicompost and manure compared
to soil treated with mineral fertilizer. In this study, organic
manure had higher activities of acid phosphatase, catalase and urease
in soils compared to those with only chemical fertilizers or no
fertilization, andVMhad the highest activities of acid phosphatase,
catalase and urease in soils under the three soil water regimes.
Because biological energy matter such as organic manure can supply
available energy, it can accelerate microorganism and enzyme
cell multiplication to improve organism and enzyme living environment
and then increase soil organism and enzyme composition
and activity (Li et al., 2000). Vermicompost differs from conventional
composting because the organic material is processed by the
digestive systems of worms (Chaoui et al., 2003).