Short project description

Nitrogen is the most vital soil nutrient, fueling plant growth, enriching microbial life, and sustaining soil fertility. It is lost from agricultural soil through various pathways, including leaching, volatilization, denitrification, and runoff. Leaching carries dissolved nitrogen in both organic and inorganic forms down through the soil profile, potentially contaminating groundwater. The EU Nitrate Directive sets a regulatory limit of 50 mg/L for nitrate concentrations in groundwater to protect water quality. While nitrate leaching has been widely studied, emerging research shows that dissolved organic nitrogen (DON) is a dominant nitrogen fraction in many freshwater systems. The growing recognition of ON's role in nitrogen cycling highlights the need to understand its dynamics in agricultural systems. This master’s thesis offers an opportunity to identify factors contributing to nitrogen loss, quantify these losses, and characterize the molecular composition of ON through literature review, lab experiments, and fieldwork on long-term experimental sites.