Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/17/2012
Publication Date: 5/1/2012
Citation: Sui, R., Fisher, D.K., Barnes, E.M. 2012. Wireless sensor network for irrigation application in cotton, Beltwide Cotton Conference, pp. 508-516. Interpretive Summary: Uncertainty in the amount and timing of precipitation is one of the most serious risks to producers in the Mid-South, and highly variable soil textural characteristics of the region require careful irrigation planning. In recent years, producers have become increasingly reliant on supplemental irrigation to ensure adequate yields and reduce risks of production, but very few use any irrigation scheduling aids. There is a need to provide technical tools to producers for appropriate management of irrigation in the region. In this research a wireless sensor network was deployed in a cotton field to continuously and automatically monitor soil water status during the growing season. The network included two systems, a Decagon system and a microcontroller-based system. The Decagon system measured soil volumetric water-content while the microcontroller-based system measured water-potential using Watermark sensors. An infrared thermometer was used in the field to measure plant canopy temperature for evaluating its usefulness in detecting water stress in cotton under humid conditions. Soil water data and plant canopy temperature were collected in 2011 cotton growing season. Results indicated that the soil water sensors were able to measure the soil water status, and the measurements recorded by the systems reflected general trends of soil water change during the growing season. Canopy temperature of non-irrigated plant is 2-4 C higher than that of the irrigated plant during the peak time of day. Irrigated plots increased cotton yield by 12% compared with the non-irrigated. System installation and maintenance procedures developed worked well in general. However, some installation and operational issues were found and need to be resolved for field operation and user acceptance.
Technical Abstract: A wireless sensor network was deployed in a cotton field to monitor soil water status for irrigation. The network included two systems, a Decagon system and a microcontroller-based system. The Decagon system consists of soil volumetric water-content sensors, wireless data loggers, and a central data station. Sensor data collected by each data logger were wirelessly transferred to and stored in the data station. The microcontroller-based system was designed to be a low-cost data logger for monitoring Watermark water-potential sensors. An infrared thermometer was used in the field to measure plant canopy temperature for evaluating its usefulness in detecting water stress in cotton under humid conditions. Soil water and plant canopy temperature data were collected during the 2011 cotton growing season. Deployment, performance, and maintenance of the systems are described and discussed.