Soil Moisture Measuring Device Testing with Electrical Capacitive Technique in Different Soil Texture

 This study had the objective as follows, 1) to study the changes of soil moisture in the soil  with  different  textures, 2)  to  compare  soil  moisture  measuring  instrument  by electrical capacity technique with the standard soil moisture content. The soil samples were collected from three orchard in Chiang Mai province for 76 days during August 26th to November 9th,2021. Soil texture was analyzed by using Hydrometer. Soil moisture content was measured by weight measurement technique and by electrical capacity measurement technique. The clay soil had 19.4%sand, 32.0%silt and 48.6%Clay which clay loam had 23.4%sand, 42.0%silt and 34.6%Clay.  The  sandy  loam  had  63.4%sand,  18.0%silt and  18.6%Clay.  After  the  soils  were saturated with water, in  the first  day, clay  soil  could  storage the highest moisture  (39.20%)followed by clay loam (38.87%) and sandy loam (23.26%). When the soil were dried at room temperature for 76 days, the moisture remained in the soil was as follows clay 3.70% , clay loam 1.62% and sandy loam 0.14% . There was inverse relationship between soil moisture by weight and electrical capacity frequency for the three studied follows; clay soil: y = -0.0385x + 9 . 1 4 7 1 clay loam: y = -0.0922x + 10.921 sandy loam: y = -0.3682x + 16.121 and regression coefficient were 0.7625 0.823 and 0.9136 respectively. When y soil moisture content and x was electrical capacity frequency.