Effect of Temperature Condition on Nitrogen Mineralization of Organic Matter and Soil Microbial Community Structure in non-Volcanic Ash Soil

This study was carried out to evaluate effect of temperature condition on nitrogen mineralization of organic matter, distribution of microbial group by PLFA profiles, and soil microbial community in non-volcanic ash soil. Dried soil 30 g mixed well each 2 g of pellet (OFPE) organic fertilizers, pig manure compost (PMC), and food waste compost (FWC). And then had incubated at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, respectively. Nitrogen mineralization rate increased with increasing temperature and that was in the order of FWC>OFPE>PMC. Distribution ratio of microbial group by PLFA profiles showed that was different significantly according to incubation temperature and the type of organic matter. As incubating time passed, density of microbial group decreased gradually. The Gram-bacteria PLFA/Gram+ bacteria PLFA, Fungi PLFA/Bacteria PLFA, and Unsaturated PLFA/saturated PLFA ratios were decreased according to the increasing temperature gradually. Principal component analysis using PLFA profiles showed that microbial community structures were composed differently by temperature factor at both 75 days ($10^{\circ}C$) and 270 days ($30^{\circ}C$). In conclusion, Soil microbial community structure showed relative sensitivity and seasonal changes as affected by temperature and organic matter type.

온도가 유기물의 질소무기화와 미생물 군집구조에 미치는 영향

온도조건이 유기물의 질소무기화율, 인지질 지방산유래 미생물 분포와 군집구조에 미치는 영향을 평가하고자 수행하였다. 비화산회토양 30 g에 입상유기질비료, 음식물퇴비, 돈분퇴비를 각각 2 g씩 잘 혼합한 후 $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$에서 항온배양을 하면서 질소 무기화량과 인지질 지방산 함량을 분석하였다. 질소 무기화율은 온도와 비례하여 증가하였으며 음식물퇴비>입상유기질비료>돈분퇴비 순으로 질소무기화율이 높았다. 지방산 유래 미생물 그룹의 분포는 온도, 유기물종류에 따라 차이를 보였으며 시간이 경과 할수록 미생물의 밀도는 감소하는 경향을 나타냈다. G-/G+, F/B, Unsat/sat비는 온도가 올라가면서 감소하였다. 인지질 지방산 함량을 이용하여 주성분 분석을 한 결과 270일에 온도에 따라 입상유기질비료는 뚜렷한 미생물군집구조를 보였다. 결론적으로 미생물 활성은 온도, 유기물 종류에 따라 상대적인 민감도와 시기별로 차이를 보였다.