Automation of soil moisture sensor-based basin irrigation system

Abstract

Irrigation is one of the largest consumers of fresh water in the agricultural sector. Surface irrigation is one the most widely adopted method of irrigation due to its simplicity and low energy requirement. Although, it is mostly associated with poor irrigation application efficiency mainly due to deep percolation and uneven distribution of irrigation water. A study was conducted in closed-end level basin layout in loamy soil to establish and test an Internet of Things (IoT) based system through a wireless connection between the automatic check gate and soil moisture sensors which can be operated remotely based on real-time soil moisture status. An attempt had been made to identify the suitable location of the sensor in the basin layout for improving irrigation application efficiency. An aluminium automatic-check gate fitted in an iron frame was placed in the concrete water supply channel to control the water flow. Three capacitance-based soil moisture sensors were placed at 25%, 50% and 75% of field length (i.e., 15 m, 30 m and 45 m) at 37.5, 15 cm and 7.5 cm depth, respectively. A wireless communication network was established between capacitance-based soil moisture sensors and an automatic check gate through the LoRa module and GSM module. The software used for automatic control of the check gate in this study was Croplytics® by Agsmartic. The system was tested for nine irrigation events under bare soil conditions. Three different operational schedules based on different soil moisture sensor placement had been tested under 40%, 30% and 20% soil moisture deficit conditions. The results suggested that the best location of sensors for closing the system would be at 37.5 cm depth placed at 25% length from the inlet in higher soil moisture deficit condition and at 7.5 cm depth placed at 75% length in low moisture deficit condition. Overall, the irrigation application efficiency was improved up to 86.6% with automation.