Small carbon- and nitrogen-containing compounds are critical to an array of important soil functions, from soil-plant interactions to atmospheric emissions to microbial metabolism. However, the concentrations of these compounds can vary quickly and over short distance scales, making them difficult to track. Here we present results from a new automated sampling system that couples up to 16 high-resolution soil water probes with laser analyzers and mass spectrometers. The resulting system can provide real-time subsurface maps of these important compounds with mm-scale spatial resolution and hour-scale time resolution.