Sistema de irrigação para cultura de alface crespa baseado em lógica fuzzy

Abstract

Lettuce is the most consumed leafy vegetable in the world and it is estimated that it moved in Brazil, in 2016, R$ 8 billion only in retail. Much of this resource is due to modern agriculture and applications of technologies, which have collaborated to maximize productivity and decrease costs. However, the agricultural sector is the largest consumer of drinking water in the world, due to the need for irrigation of different crops. Lettuce, like other leafy crops, is characterized by a shallow root system that requires strict irrigation control, inadequate soil moisture, even in relatively short periods, can affect the crop. This work presents the theoretical and experimental development of a fuzzy controller for irrigation, based on the sensing of soil moisture, in order to improve the control of water use for curly lettuce and to evaluate the quality of production with and without the use of this controller. To this end, an experiment was designed to compare two methods of drip irrigation: automatic irrigation by fuzzy controller and manual irrigation by replacement of evapotranspiration. The controller consists of an ATmega328 microcontroller (Arduino Nano prototyping board), DM v1.2 soil moisture sensor and a solenoid valve. As a result, the averages of five characteristics of the lettuce were analyzed, whose values ​​presented are, respectively, for automatic irrigation and manual irrigation: weight of 76.6 ± 12.3 g and 77.6 ± 16.9 g; height of 14.9 ± 1.3 cm and 15.0 ± 1.9 cm; head diameter of 27.6 ± 1.8 cm and 27.4 ± 1.5 cm; stem diameter of 16.0 ± 0.9 mm and 16.3 ± 1.3 mm; and number of sheets of 16.9 ± 1.4 units and 16.9 ± 1.6 units. The results obtained indicate that the controller fuzzy produced lettuces statistically equal to those produced by irrigation by replacement of evapotranspiration, however, with an economy of 11% in the use of water, considering the consumption obtained of 25.56 L, for automatic irrigation, and 28.69 L for manual irrigation.