Automation of irrigation by electronic tensiometry based on the arduino hardware platform

Abstract This study developed and evaluated an electronic irrigation system controlled by soil water matric potential. The controller uses tensiometers and pressure transducers as a reading mechanism, integrated with an Arduino microcontroller board that drives the solenoid valves and a 1/3 hp single-phase motor. Four electronic tensiometers were installed in plastic containers filled with 6 kg of Red-Yellow Latosol (RYL) with a clayey texture, and another four in plastic containers filled with 7 kg of Regolitic Neosol (RN) with a sandy texture. Irrigation automation components were activated autonomously at the critical potentials of -20, -25, -30, and -35 kPa for RYL, and -10, -15, -20, and -25 kPa for RN, with a 20% variation tolerance. The entire system is able to monitor and control irrigation based on soil water matric potential. Components were deactivated when the soil water potential reached the field capacity of each soil type. Irrigation automation performance was considered satisfactory, as it kept critical potentials within the pre-established thresholds in both soil types. Automation control was set for matric potentials between -10 kPa and -35 kPa in RYL, and between -5 kPa and -25 kPa in RN.

摘要 本研究开发并评估了一套以土壤水基质势（soil water matric potential）为调控依据的电子灌溉系统。该系统的控制器以张力计与压力传感器作为信号采集单元，集成了驱动电磁阀与1/3马力单相电机的Arduino单片机开发板。研究人员在装有6千克黏质质地砖红壤（Red-Yellow Latosol，缩写RYL）的塑料容器中布设4台电子张力计，另在装有7千克砂质质地岩性新成土（Regolitic Neosol，缩写RN）的塑料容器中同样布设4台电子张力计。针对RYL土，灌溉自动化组件将在基质势达到-20、-25、-30与-35 kPa时自动启动；针对RN土，启动阈值为-10、-15、-20与-25 kPa，允许20%的波动容差。整套系统可基于土壤水基质势实现灌溉的全程监测与自动调控，当土壤水基质势达到对应土类的田间持水量时，系统组件将自动关停。本次灌溉自动化系统的运行效果被评定为良好，其可将两种供试土类的基质势稳定维持在预设阈值范围内。本研究设置的自动化控制区间为：RYL土的基质势范围为-10 kPa至-35 kPa，RN土则为-5 kPa至-25 kPa。