Generally the size of farmland is large. It is high cost and poor flexibility to use wired network. Aiming at this situation, a farmland environment monitoring system by using the ZigBee wireless sensor network technology as the core and a scheme on node energy optimization are presented. This system includes two parts: the information collection and the data storage. The information collection consists of end-node, router-node and coordinator-node. Parameters such as temperature, humidity and soil electric conductivity are measured by end-node and router-node. Coordinator-node is responsible for collecting datum. The data storage consists of server and computer. The experimental result shows that the network which uses energy aware and energy efficiency method can live longer and send more data. This monitoring system may provide data support to the development of precision agriculture.