Sampling at high spatial and temporal resolutions with an experimental chamber

Summary Laboratory‐scale studies of the dynamics of soil biogeochemical processes often require destructive sampling for chemical, biological and genetic analyses. The consequences are either ‘end‐of‐experiment’ sampling or a set‐up with multiple experiments in parallel, of which some are sacrificed over time. We propose an alternative experimental set‐up to enable matrix sampling and monitoring at high spatiotemporal resolution of chemical, biological and physical properties. A customized experimental chamber was constructed, including an array of sensors on one side and hundreds of sampling ports on the other. A vertical unidirectional flow regime was maintained in the chamber, and soil samples were collected through ports that were not adjacent laterally to ones used in an earlier sampling campaign. We give an example of an experiment with such a chamber in which the environmental conditions (matric head and redox) were kept almost uniform in the horizontal dimension. Under these conditions nitrogen cycling was also almost the same in the lateral dimension. This system offers a unique combination of high spatial and temporal resolution sensors in the same system that is destructively sampled. Highlights A new experimental chamber allows high‐resolution sampling In unidirectional flow, sacrificial sampling can be avoided