TY - JOUR ID - 67036 TI - The effect of irrigation water turbidity on measurement accuracy of water content by Theta prob device JO - Iranian Journal of Soil and Water Research JA - IJSWR LA - en SN - 2008-479X AU - Ghaedi, Saeed AU - Afrasiab, peyman AU - Delbaril, Masoomeh AD - Ph.D. Student, Water Engineering Department, Zabol University, Zabol, Iran AD - Associate Professor, Water Engineering Department, Zabol University, Zabol, Iran Y1 - 2018 PY - 2018 VL - 49 IS - 4 SP - 729 EP - 737 KW - constant dielectric KW - irrigation water turbidity KW - ML2 Model of Theta prob device KW - Soil Texture DO - 10.22059/ijswr.2017.233358.667680 N2 - One of the methods of indirectly measuring amount of soil moisture is using Theta prob device. Since it is based on the constant dielectric of soil, factors affecting the physical and chemical properties of soil have a great impact on the accuracy of the device measurement. The aim of this study is the effect of irrigation water turbidity on measurement accuracy of water content of the soil by Theta prob device. Because of this, three different soil texture (silty loam, sandy loam and loam) were on different levels of irrigation water turbidity. The levels of irrigation water turbidity include 10, 1000, 2000 and 3000 NUT. The result indicated that factors of soil texture and irrigation water turbidity in significant level (P<0.01) have impact on measurement of humidity accuracy by ML2 Model of Theta prob device. Increasing the level of irrigation water turbidity in each of three soil texture leads to reducing the accuracy of device measurement and most errors were observed in loam which has highest percentage of clay. Also, the result showed that specific calibration of the device functions (special linear and special nonlinear) is more accurate compared to other calibration functions which indicate necessity of special calibration for all soils are tested. UR - https://ijswr.ut.ac.ir/article_67036.html L1 - https://ijswr.ut.ac.ir/article_67036_2986145a33870ba56b6399bc430ee710.pdf ER -