A Wireless Soil Moisture Sensing Network to Automate Site-Specific Irrigation of Cotton Using a Lateral Move Irrigation System Using a Lateral Move Irrigation System

The overall goal of this project was to create and field-test an affordable system to help cotton farmers increase water use efficiency by automating irrigation based on real-time soil moisture data using a wireless sensor network. The specific objectives were to: (1) Develop a wireless sensor network to automate irrigation scheduling of cotton, based on real-time soil moisture using a lateral move irrigation system, and (2) field-test the irrigation automation system by evaluating the response of cotton to three irrigation trigger points. A wireless soil moisture sensor network prototype created in 2019 to automate irrigation of cotton using a subsurface drip irrigation (SDI) system was modified and adapted to a lateral move irrigation system.  A field experiment was conducted at the Edisto Research and Education Center in 2020 to field-test the irrigation automation system. In this experiment, three irrigation treatments were evaluated in which irrigation was automatically applied to cotton when the weighted-average soil moisture reached either 30, 40, or 50 kPa using four replications. Soil moisture was measured using Watermark moisture sensors installed at 3 depths in each plot. The electronics and software for the automation system were developed and installed in the field. Limited testing during one irrigation event in mid-September showed that the system worked as expected. However, early-season delays due to COVID-19 prevented us from evaluating objective 2 during the whole growing season.