Soil Moisture and Plant Canopy Temperature Sensing for Irrigation Application in Cotton

Abstract

There is a need to provide technical tools to cotton producers for appropriate management of irrigation in the Mid-South region of the U.S.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 consisted 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. 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. Soil water content decreased at a higher rate in 15-cm and 30-cm depths than in 60-cm depth before 60 days after planting. A sharp decrease of soil water content in 60-cm depth was observed from 60 to 80 days after planting. Sensor measurements responded to effects of soil texture on available water capacity. Canopy temperature of non-irrigated plants is 2-4 C higher than that of the irrigated plants during peak time of day. Supplemental irrigation increased yield by 14.2 % in this study. System installation and maintenance procedures developed worked well in general. Some installation and operational issues were found and need to be resolved for wider field operation and user acceptance.

Field Study of Variable Rate Irrigation Management in Humid Climates

“…Much research has been done on the use of sensors and the global positioning system (GPS) to gather information on soil and plant conditions, which includes using electrical conductivity sensors to map soil electrical conductivity (EC) (Rhoades et al, 1997;Kitchen et al, 1999;Fraisse et al, 2001;Johnson et al, 2003), soil moisture sensors to measure soil moisture content or soil water potential (Dukes and Scholberg, 2004;Evett and Parkin, 2005;Robinson et al, 2008;Vellidis et al, 2008;Sui and Baggard, 2015), thermal irradiation sensors to detect plant canopy temperature (Jackson, 1986;Cohen et al, 2005;O'Shaughnessy and Evett, 2009;Sui et al, 2012), spectral reflectance and ultrasonic sensors to predict plant health characteristics (Sui et al, 1989;Kostrzewski et al, 2003;Sui and Thomasson, 2006;Detar et al, 2006;Yin et al, 2012, Sui et al, 2013, and mass-flow sensors to map crop yields (Searcy et al, 1989;Grisso et al, 2009;Thomasson and Sui, 2003).…”

Forty Years of Increasing Cotton’s Water Productivity and Why the Trend Will Continue

“…Researchers have shown that soil water sensors can effectively be used for irrigation scheduling. However, procedures for proper installation, calibration, and maintenance of soil water sensing devices are critical for the success of the sensor-based irrigation scheduling (Yoder et al, 1997;Leib et al, 2003;Evett et al, 2006;Sui et al, 2012).…”

A Simple Thermistor Design for Industrial Temperature Measurement

“…According to Nedic & Eric (2014), metal cutting temperature was measured with artificial thermocouple and metal machine-ability was analyzed from aspect of cutting temperature. In Sui et al (2012), LM35 and PIC16F873 microcontroller was used to build a device which can measure safely the indoor temperature in firm buildings such as greenhouses, warehouses or silos. Afsarimanesh and Ahmed (2011) used AT89C51 and LM35 to build a system which measures temperature and stores them in the EEPROM of the microcontroller.…”