Application of a high-throughput laboratory method to assess litter decomposition rates in multiple-species experiments

Laboratory decomposition experiments measuring the mineralization of C from plant residue are increasingly used to test the effects of different litter sources and soil conditions. To date, the most widely used methods are infra-red gas analysis (IRGA) and gas chromatography, which are time-consuming, and relatively expensive and complex to operate. The aim of this study was to devise a simple and rapid laboratory method to assess litter decomposition rates at frequent time intervals. We modified the MicroResp™ system to measure the amount of CO2 produced by two soils supporting contrasting microbial communities and containing the litter of eight crop species. The method was sensitive enough to differentiate both soil microbial communities and litter qualities. The method combines the accuracy of gas chromatography with the speed of absorbance measurements obtained via microplate readers. This technique provides an effective means for devising complex litter decomposition experiments capable of addressing the joint influence of multiple species, soil communities, environmental conditions, and their multiple interactions.