Effect of Temperature on Soil Microbial Biomass, Enzyme Activities, and PLFA content during Incubation Period of Soil Treated with Organic Materials

This study was carried out to evaluate the effect of temperature on soil microbial biomass, enzyme activities, and PLFA content in the volcanic(VAS) and the non-volcanic ash soil(NVAS). The soils were treated with organic materials such as organic fertilizer pelleted(OFPL), organic fertilizer powdered(OFPD), pig manure compost(PMC), and food waste compost(FWC). Two grams of organic materials were well mixed with 30g of dried volcanic and non-volcanic ash soil(< 2 mm) with 50% of soil moisture content. And the soils were incubated at 10, 20, $30^{\circ}C$ in incubator. Soils were analysed on the incubation times as followed; soil pH, total nitrogen, organic matter(at 75, 150, 270 days), microbial biomass C and PLFA (at 75, 270 days), microbial biomass N and soil enzyme(at 150, 270 days). pH values of soils treated with PMC and FWC had no changes on soil type, and incubation temperature. However, the pH was increased with temperature in the soils treated with OFPL. The changes in NVAS was higher than in VAS. Soil microbial biomass C content were high in the condition of high temperature and organic fertilizers treatment in VAS. But the contents were gradually decreased with incubation period in both NVAS and VAS. Soil microbial biomass N was high in NVAS treated with organic fertilizers and in VBS treated with PMC and FWC. PLFA content was higher in NVBS than in VBS at 75 days but showed high in VBS at 270 days. Urease activity of NVBS treated with OFPL showed $10^{\circ}C$ (75.0)> $20^{\circ}C$ (16.3)>$30^{\circ}C$ ($4.6ug\;NH{_4-}N\;g^{-1}\;2h^{-1}$) at 150 days. It were decreased gradually high temperature and time passes. And it showed high at $10^{\circ}C$ in VBS. Glucosidase activity was higher in NVBS than in VBS. Correlation coefficient of between soil microbial biomass C and microbial activity indicators showed that PLFA was high significantly at $r^2=0.91$ in NVBS and ${\beta}-glucosidase$ was $r^2=0.83$ in VBS. Soil microbial activities showed differences in the relative sensitivities of soil type and soil temperature.

유기물원 항온배양 온도가 토양미생물체량과 효소활성 및 PLFA함량에 미치는 영향

유기물원을 항온 배양했을 때 온도가 토양미생물체량과 효소활성 및 PLFA함량에 미치는 영향을 토양 특성별로 평가하고자 입상과 분상 혼합유기질비료, 돈분퇴비, 음식물퇴비를 화산회토양과 비화산회토양 30g에 2g을 잘 혼합 후 10, 20, $30^{\circ}C$에서 항온배양을 하면서 pH, 토양질소, 유기물 함량, Microbial biomass C와 N, 토양효소활성, 인지질지방산 함량을 분석하였다. 돈분과 음식물퇴비는 토양종류와 온도에 상관없이 토양 pH의 변화가 크지 않았으나 입상유기질비료는 온도가 높을수록 낮아졌으며, 비화산회토양에서 변화폭이 컸다. 미생물체량 C는 화산회토양의 경우 배양 온도가 높고 유기질비료를 처리할 때 높아지는 경향이었지만 토양종류에 상관없이 점차 감소하였다. 미생물체량 N은 비화산회토양에서 유기질비료, 화산회토양에서는 돈분과 음식물퇴비를 처리할 때 높게 나타났다. 인지질 지방산함량은 항온배양 75일후 비화 산회토양이 화산회토양보다 높았고, 270일후 화산회토양에서 높게 나타났으나 점차 낮아지는 경향이었다. Urease활성은 150일에 비화산회토양의 입상유기질비료처리에서 $10^{\circ}C$(75.0)>$20^{\circ}C$(16.3)>$30^{\circ}C$($4.6ug\;NH{_4-}N\;g^{-1}\;2h^{-1}$)순으로 $10^{\circ}C$에서 가장 높게 나타났으며 온도가 높고, 시간이 경과할수록 낮아졌으며 화산회토양의 Urease활성은 $10^{\circ}C$에서 높게 나타났다. ${\beta}-glucosidase$ 활성은 비화산회토양이 화산회토양보다 높았고 시간이 경과할수록 낮아졌다. 토양미생물체량 C와 미생물활성지표간의 상관계수는 비화산회토양에서 PLFA ($r^2=0.91$), 화산회토양에서 ${\beta}-glucosidase$ ($r^2=0.83$)가 높았으며, 미생물활성지표는 토양종류와 온도에 따라 상대적으로 민감도가 다르게 나타났다.