Assess graduate-level understanding of nitrogen cycling processes and management strategies in temperate agroecosystems. The quiz will test N transformation mechanisms (mineralization, immobilization, nitrification, denitrification, volatilization), sources and sinks (fertilizer, biological fixation, deposition, plant uptake, leaching, gaseous losses), soil–plant–microbe interactions, measurement and modeling approaches (incubations, 15N tracing, process-based models), and effects of management practices (rate/timing/form of fertilizer, cover crops, rotations, tillage, drainage, buffer strips) on N use efficiency and environmental outcomes; tasks include explaining mechanisms, interpreting data, and evaluating mitigation trade-offs under temperate conditions.