Abstract: In order to meet the needs of precision agriculture， a wireless monitoring system for precision seeder was designed based on Zigbee， using wireless sensor networks and PLC controller technology. In the system， photoelectric sensors were used to detect the state of seeding. The information collected will be sent to PLC through wireless transmission module. A hall sensor was used to detect the speed of the tractor， along with a stepper motor used to drive the seed shaft. Real\|time detection and control of the sowing conditions and the synchronism of seeding rate and tractor speed is achieved. The experiments showed that the system has high reliability and high precision， and high\|speed communications real\|time monitoring of seeding information was effectively realized at the same time.

Key words: wireless sensor networks, PLC, sowing quality, monitoring system