Gypsum and Texture Effects on the Estimation of Saturated Paste Electrical Conductivity by Two Extraction Methods

Abstract

Texture and salt type can influence the relationships between saturated paste electrical conductivity (EC_e) and EC of other soil/water ratios. The objectives of this study were to develop and validate relationships among EC_e, EC_1∶2, and EC_1∶5 for soils in Yazd Province, and evaluate the effects of texture and gypsum on those relationships. Two hundred thirty‐six soil samples were collected, of which 200 were used to develop and 36 were used to validate the models. The soils were divided into two textural categories, coarse and fine, and two categories, with and without gypsum. The 1∶2 procedure predicted EC_e of slightly more than 1∶5. Gypsum content had stronger impact on the accuracy of models in predicting EC_e than texture. The EC_e=4.0723EC_1∶2−5.7135 and EC_e=3.5142EC_1∶2+0.7615 models are recommended for soil with and without gypsum, respectively. The methodology can be implemented in any other region, particularly if gypsum is present.

Keywords:

• Arid soils
• electrical conductivity
• extraction method
• salinity