عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Determination of soil water content using Time Domain Reflectometery (TDR) method is recently considered modern and widely used. For practical applications, TDR needs to be calibrated based on relationship of dielectric constant and volumetric moisture content of soil. There are many empirical correlations between dielectric constant and volumetric moisture content that these equations don’t spot all of soil characteristic. The paper presents investigation of models accuracy for soil organic matter. This study was carried out in laboratory conditions based on complete randomized design separately for three soil textures including light, medium and heavy. The treatments in each experiment were different contents of soil organic matter (0.5, 2, 3.5, 5, 6.5 %) with three repetitions. In this study investigated the accuracy of Topp et al (1980), Mixing (1990), Malicki et al. (1996), Roth et al. (1992) and Oleszczuk et al. models (2004). The estimation potency of moisture content of these models survey with scales (RMSE) and (RE). The results showed that the models of Topp et al. (1980), Malicki et al. (1996) and Oleszczuk et al. (2004) with correlated coefficient 0.85, 0.84 and 0.84, least different and Roth et al. (1990) and mixing models, were most different in estimation of soil water content. Also in these models in high percent of soil organic matter and Clay, increased the amount of error in estimation of soil water content.