The development of site-specific water management systems for sprinkler irrigation will be a major factor in future efforts to improve the various efficiencies of water-use and to support a sustainable irrigated environment. The challenge is to develop fully integrated management systems with supporting elements that accurately and inexpensively sense within-field variability and then optimally control variable-rate water application systems in ways that account for the spatial variability affecting water use. Recent advances in sensor and wireless radio frequency (RF) technologies have enabled the development of distributed in-field sensor-based irrigation systems to support site-specific irrigation management. Thus, integration of a decision-making process with a distributed wireless sensor network (WSN) and providing real-time input to site-specific controls is a viable option. This presentation reviews research on the implementation of in-field micrometeorological information that was fed from a distributed wireless sensor network (WSN) and displayed on a geo-referenced field map in a computer base station. Low-cost Bluetooth wireless RF communications from both a distributed WSN and the machine controls monitoring of sprinkler status and global positioning system (GPS) location were interfaced with a computer base station for processing by a decision support program, which updated the instructions to the variable rate irrigation controller for real-time site-specific control. The decision support was optimized to adapt changes of crop type, irrigation pattern, and field location for instructions for individual sprinkler heads on how much water to apply and where. A graphical user interface (GUI) with a simple click-and-play menu was used, which allowed growers to remotely access field conditions and irrigation status at the home or office via wireless RF communications.