A simple method for in-situ assessment of soil respiration using alkali absorption

•The Respicond VIII respirometer can be adapted to field conditions.•Respiration results coincide with infrared gas analyzer data.•New method is suitable for spatially resolved detection of soil respiration.

Lacking knowledge about the spatial heterogeneity of heterotrophic soil respiration (Rh) hampers the prediction of larger-scale soil CO2 efflux in patchy landscapes. The aim of this study was to establish a cost-efficient method for the rapid and simultaneous assessment of cumulative heterotrophic soil respiration (CO2) at different sample spots. For this purpose, we adapted the laboratory-based, fully-automated Respicond VIII respirometer (Respicond) to detect CO2 emission under field condition, installed the device in two temperate grasslands, and compared the Rh flux data with those obtained using the so-called dynamic chamber method with infrared gas analyzers (IRGA). The results revealed good agreement between both Rh measurements (Slope = 0.89, R2 = 0.99). We conclude that adapting the Respicond for detection of CO2 under field conditions is principally feasible, thus providing a new tool for the simultaneous assessment of CO2 fluxes from different soil ecosystems.