1年以上。 According to the requirements for precision agriculture applications, the commonly-used node power supply in sensor networks and its characteristics are analyzed. To extend the node lifecycle powered by ordinary dry-cell batteries, an application layer operated node dormant/synchronization mechanism is proposed and a duty cycle computing method depending on the node lifecycle expectation and data acquisition demands is also provided, based on the node energy analysis. Finally, this dormant/synchronization mechanisms is realized on actual sensor networks nodes, and a large number of experiments were executed at Xiaotangshan agricultural bases of the National Engineering Research Center for Information Technology in Agriculture. The experimental results show that the node with dormant design increases its lifetime from about 150 hours to more than one year.