Seasonal Changed of Microbial Population in the Field Soil

계절에 따른 토양중 미생물의 밀도 변화

  • Park, Dong-Jin (Korea Research Institute of Bioscience & Biotechnology, KIST) ;
  • Lee, Sang-Hwa (Korea Research Institute of Bioscience & Biotechnology, KIST) ;
  • Kim, Chang-Jin (Korea Research Institute of Bioscience & Biotechnology, KIST)
  • Received : 1998.07.03
  • Accepted : 1998.09.12
  • Published : 1998.09.01

Abstract

Soil microorganisms including bacteria, fungi, and actinomycetes were seasonally isolated at depths (0.5~2, $10{\pm}1$, $50{\pm}1cm$) of field. The frequency of microbial isolates was employed for the determination of microbial population (CFU/g dry soil) and distribution ratio (%) in soil. Both bacteria (24-fold) and actinomycetes (7-fold) exhibited the biggest change at the depth of $50{\pm}1cm$, whereas fungi showed the maximum (13-fold) at $10{\pm}1cm$. On the whole, the bacterial population was high in spring soil, fungi in winter, and actinomycetes in autumn. Soil microorganisms also exhibited the seasonal variation on their distribution ratio (%). The maximum distribution ratio (85.7%) of bacteria was observed at the depth of $50{\pm}1cm$ in spring, whereas bacteria showed the minimum (35.2%) at the depth of $10{\pm}1cm$ in spring. The maximum distribution ratio (23.0%) of fungi was found at the depth of $50{\pm}1cm$ in spring, whereas its minimum (0.5%) at the depth of $10{\pm}1cm$ in spring. Actinomycetes exhibited the maximum distribution ratio (45.2%) at the depth of $10{\pm}1cm$ in spring, whereas its minimum (12.2%) was showed at the depth of $50{\pm}1cm$ in spring.

Keywords

seasonal change;microbial population;microbial isolation;soil depth