Abstract |
We studied soil composition, N2O production, a number of
denitrifying bacteria, community structure and T-RFLP
patterns of denitrifying bacteria dependent on agricultural
methods with the change of seasons. Analyses of the soil
chemical composition revealed that total carbon and total
organic carbon contents were 1.57% and 1.28% in the organic
farming soil, 1.52% and 1.24% in the emptiness farming soil,
and 1.40% and 0.95% in traditional farming soil, respectively.
So, the amount of organic carbon was relatively high in the
environment friendly farming soils than traditional farming
soils. In case of N2O production, the amount of N2O production
was high in May and November soils, but the rate of N2O
production was fast in August soil. The average number of
denitrifying bacteria were 1.32 × 104 MPN · g-1 in the organic
farming soil, 1.17 × 104 MPN · g-1 in the emptiness farming
soil, and 6.29 × 103 MPN · g-1 in the traditional farming soil. It
was confirmed that the environment friendly farming soil have
a larger number of denitrifying bacteria than the traditional
farming soil. As a result of the phylogenetic analyses, it was
confirmed that six clusters were included in organic farming
soil among total 10 clusters. And the result of PCA profile
distribution of T-RFLP pattern on agricultural methods, the
range of distribution showed wide in the organic farming
method, relatively narrow in the conventional farming method,
and middle in the emptiness farming method. Therefore, we
could concluded that the distribution and the community
structure of denitrifying bacteria were changed according to the
agricultural methods and seasons. |