Measuring the CO₂ production from maize‐straw‐amended soil columns— a comparison of four methods

Abstract

A soil‐column experiment with maize‐straw application at different depths was carried out to investigate the accuracy of CO2‐measurement systems in a greenhouse experiment with sandy and loamy soils. The classical approach of CO2 absorption in NaOH solution was compared with three other methods using dynamic chambers. These methods were gas chromatography (GC), a portable infrared analyzer (IR), and a portable photo‐acoustic system (PAS). The cumulative CO2 production over the 57‐day incubation period was significantly affected by the method and soil‐specifically by the treatments. The NaOH and GC method always formed a pair of lowest cumulative CO2 production in all treatments with maize‐straw addition. In the treatments with bottom application of the maize straw, IR and PAS methods gave values at identical levels in both soils. In the treatments with top application of the maize straw, the IR method gave significantly highest values in the sandy soil and the PAS method in the loamy soil. The correlation coefficients between the cumulative CO2 production of the three dynamic‐chamber methods (GC, IR, and PAS) and the static NaOH method were all significant, with r values between 0.90 and 0.93. The C balance can be used for testing the plausibility of CO2‐production data. Roughly 102% (NaOH and GC) and 114% (IR and PAS) were recovered, including the CO2‐production data in the C balance of the sandy soil. The respective data were 97% (NaOH and GC) and 104% (IR and PAS) for the loamy soil.

Changes in CO2 Absorption Efficiency of NaOH Solution Trap with Temperature

“…)형태로 안정화 시킨 후 남은 알칼리를 산으로 역적정하여 분석할 수 있다 (Haney et al, 2008;Rottmann et al, 2009). 분석 방법별로 CO 2 플럭스를 비교하면, NaOH 방법과 GC의 회수율이 97~102%임에 반해, IR 방법은 104~114%로 다소 과대 평가되지 만 밀폐와 같은 인위적인 요인을 제거할 수 있다는 장점이 있다 (Rottmann and Joergensen, 2011).…”

“…NaOH 방법은 고가의 장비가 필요 없어 실험실내 항온 배양 실험에서 토양 호흡량을 측정하는 데 가장 빈번하게 이 용되지만, 항온 배양 기간 동안 용기를 밀폐시켜야 하기 때문에 토양 미생물에 필요한 산소 공급이 제한적일 수 있다 는 단점이 있다 (Lucretia et al, 2012;Rottmann and Joergensen, 2011). 이와 같은 단점에도 불구하고, 특정 처리에 따른 미생물 호흡량 비교 연구에서는 큰 문제 없이 사용된다 (Lim et al, 2012(Lim et al, , 2017 (Harris et al, 1997;Jeon et al, 2017).…”