Soil carbon dioxide efflux determined from large undisturbed soil cores collected in different soil management systems

Abstract

The aim of this study was to evaluate a measuring technique for determining soil CO2 efflux from large soil samples having undisturbed structure under controlled laboratory conditions. Further objectives were to use the developed measuring method for comparing soil CO2 efflux from samples, collected in three different soil management systems at various soil water content values. The experimental technique was tested and optimised for timing of sampling by taking air samples after 1, 3 and 6 hours of incubation. Based on the results, the incubation time was set to three hours. The CO2 efflux measured for different soil management systems was the highest in the no-till and the lowest in the ploughing treatment, which was in accordance with measurements on accessible organic carbon for microbes. An increase in CO2 efflux with increasing soil water content was found in the studied soil water content range. Our results indicate that soil respiration rates, measured directly after tillage operations, can highly differ from those measured long after.