This chapter explores the design of wireless sensor networks for applications in precision agriculture. A short review of developments in precision agriculture and recent applications of wireless sensor networks in the area is presented. The authors present their design of medium access control and network layer protocols exploring the challenges and opportunities associated with the design of such a networked system. The physical layer in their network allows multiple power modes in both receive and transmit operations. The MAC layer employs these multiple power modes to implement a novel wake-up synchronization mechanism to reduce the energy overhead. The network layer ensures reliable collection of data while balancing the energy consumption among the nodes. Finally, the authors present an analytical approach to model the behavior of the MAC protocol developed and compare it against the duty-cycle based S-MAC protocol. The results are also confirmed using simulations.