Prediction of Soil Sodicity (ESP) from SAR Values in Various Soil Water Extracts

Abstract

This study was carried out at two locations i.e Sileit Agricultural Scheme and Kenana 4 ,the samples were taken from different depths. Ninety (90) soil samples were collected from the two areas to represent saline and non saline soils. Samples were tested for: 1. Exchangeable Sodium Percentage (ESP) 2. Total Soluble Salts ( E.C.) 3. Sodium Adsorbation Ratio value (SAR) 4. pH The purpose of this study is to determine the relationship between ESP and SAR Values at different dilutions ( saturated paste Extract, 1 : 2.5 and 1 : 5 soil : water suspension ) . This study is to reduce the high cost of measuring ESP which necessitates determination of cation exchange capacity (CEC), extractable sodium, and soluble sodium. They all require chemicals, valuable equipment and human efforts. Statistical analysis was carried out and regression equations were developed between the measured values of ESP and SAR at different soil: water dilutions (paste extract, 1 :2.5 and 1:5 ) .Regression equations were then used to calculate ESP . The relationship between calculated and actually determined ESP values was highly significant for all the dilutions used, including the 1:5 soil: water ratio which is widely adopted in soil laboratories.