Open AccessSoil Moisture Sensor Test with Mississippi Delta Soils
Author(s) -
Ruixiu Sui,
H. C. Pringle,
Edward M. Barnes
Publication year - 2019
Publication title -
transactions of the asabe
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.396
H-Index - 101
eISSN - 2151-0040
pISSN - 2151-0032
DOI - 10.13031/trans.12886
Subject(s) - water content , environmental science , soil water , gravimetric analysis , repeatability , soil science , irrigation , moisture , soil test , soil moisture sensor , hydrology (agriculture) , irrigation scheduling , greenhouse , geotechnical engineering , geology , agronomy , chemistry , geography , meteorology , organic chemistry , chromatography , biology
. One of the methods for irrigation scheduling is to use sensors to measure the soil moisture level in the plant root zone and apply water if there is a water shortage for the plants. The measurement accuracy and reliability of the soil moisture sensors are critical for sensor-based irrigation management. This study evaluated the measurement accuracy and repeatability of the EC-5 and 5TM soil volumetric water content (SVWC) sensors, the MPS-2 and 200SS soil water potential (SWP) sensors, and the 200TS soil temperature sensor. Six 183 cm × 183 cm × 71 cm wooden compartments were built inside a greenhouse, and each compartment was filled with one type of soil from the Mississippi Delta. A total of 66 sensors with 18 data loggers were installed in the soil compartments to measure SVWC, SWP, and soil temperature. Soil samples were periodically collected from the compartments to determine SVWC using the gravimetric method. SVWC measured by the sensors was compared with that determined by the gravimetric method. The SVWC readings from the sensors had a linear regression relationship with the gravimetric SVWC (r 2 = 0.82). This relationship was used to calibrate the sensor readings. The SVWC and SWP sensors could detect the general trend of soil moisture changes. However, their measurements varied significantly among the sensors. To obtain accurate absolute soil moisture measurements, the sensors require individual and soil-specific calibration. The 5TM, MPS-2, and 200TS sensors performed well in soil temperature measurement tests. Individual temperature readings from these sensors were very close to the mean of all sensor readings. Keywords: Irrigation, Sensors, Soil types, Soil water content, Soil water potential.