2015 Volume 8 Issue 4 Pages 228-234
The automation of irrigation systems based on sensor technology has the potential to maximize the efficiency of water use. A prototype of an autonomous irrigation controller consisting of an 8-bit MCU and a 12-bit AD converter was developed and tested in tomato greenhouses. Two algorithms for water control, i.e. a variable keepepause method and a required water calculation method, were programmed. The irrigation controller showed the ability to measure soil tensions in real-time and to properly trigger irrigation at a set value. The system performance for maintaining soil tensions based on the keepepause method was strongly affected by sunlight, whereas the water calculation method provided a simple irrigation operation without frequent irrigation, while supplying the amount of water needed during each irrigation period.