© 2015 IEEE. The pervasiveness property of wireless sensor network technology makes it suitable to collect heterogeneous sensor data in the application field of precision agriculture. On the basis of the collected data, smart and adaptive irrigation strategies have been proposed to estimate the optimal water quantity needed by cultures. This paper is aimed at presenting a wireless system architecture for smart irrigation, which adaptively evaluates the irrigation time according to the environmental conditions. A selected set of experimental results are presented to show the potentialities of the system to adaptive control the irrigation procedure toward water saving and product quality optimization.