A cost-effective high-throughput microcosm system for studying nitrogen dynamics at the plant-microbe-soil interface

In the present study a new microcosm system was evaluated for its suitability to investigate nitrogen dynamics between soils, plants and microbes. Five different agricultural soils were homogenized and transferred in the test tubes, and kept under controlled conditions in a climate chamber for 4weeks. Soils differed clearly in nitrogen pools and microbial population structures but less in their activities. Bacterial and fungal community compositions and soil properties, except gross N transformation rates, remained stable and reproducible during the test period in all soils. N-15 tracer studies showed that N uptake patterns of barley as well as plant growth were linear in the initial growth period. Overall, the presented microcosm system proved to be a powerful tool to elucidate N pathways in soil-plant-microbe systems. In future studies the microcosm system may greatly help generating new insights in the complex processes and controls of nitrogen biogeochemical cycle in agricultural systems.