Identificatioin of nitrate-nitrogen (NO₃-N) in drainage water allows accessing the effectiveness of water quality management. A wick-type lysimeters was used to monitor water flux and NO₃-N  leached below the root zoon under irrigated cropping system. A wireless lysimeter design was proposed and evaluated. A distributed wireless in-field sensor network was developed for real-time lysimeter monitoring. Twelve lysimeters were installed across the field and equipped with two rain gauges to measure amount of drainage water. Two TDR soil moisture sensors were installed above the lysimeter to continually monitor soil water contents. Sensors and a data logger were self-powered by a solar power and sensory data was periodically sampled and wirelessly transmitted to a base computer 500 m away from the field via Bluetooth spread spectrum radio communication. The computer was bridged to web server for real-time lysimeter monitoring on internet.