Low-cost and high-efficiency automated tensiometer for real-time irrigation monitoring

ABSTRACT Knowing the soil moisture available to plants is important for adequate management of water use in agricultural farms, with automated methods being most accurate. However, acquisition costs are high and commercially irrigation controllers still work using pre-set times. This study aimed develop calibrate a low-cost tensiometer efficiency control, based on real-time monitoring. The research was conducted at Laboratories Hydraulics Water Soil Plant Atmosphere Relationship, which belong Federal University Grande Dourados (UFGD), Dourados, MS, Brazil, classified as an Oxisol. Pressure transducers microcontroller were used assimilate pressure inside tensiometers transform it into readings matric potential (Ψm). Thus, calibration carried out by comparing different transducer digital tension meter. Different tensions applied obtain curve, starting from humid point (saturated) driest one (oven-dried soil), collecting 20 valid points. Subsequently, data subjected normality test, subsequent statistical analysis regression curve models. Linear adjustments coefficient determination (R2 = 0.99) observed, system built this capable monitoring real-time.