The impact of agricultural land use on the composition of dissolved organic matter (DOM) and its effects on the aquatic carbon cycle are still largely unknown. A sensor for dissolved DOM in stream ecosystems based on fluorescence measurement was developed. It’s an easy to use handheld optical system for online monitoring of DOM under field-conditions. For the determination of DOM two indices are used, namely the freshness index (BIX) and the fluorescence index (FIX).
