Modeling of Soil Exchangeable Sodium Percentage Function to Soil Adsorption Ratio on Sandy Clay Loam Soil, Khartoum- Sudan

An experiment was conducted at the Wadi Soba farm, Khartoum- Sudan. The aim of this study is to estimate the Exchangeable Sodium Percentage (ESP) function to Sodium Adsorption Ratio. In this study, linear regression model (ESP-SAR model) for predicting soil ESP from SAR was suggested. For this purpose, 30 soil samples were collected from the field of experiment, soil ESP was estimated from soil SAR in order to compare the predicted results with measured SAR using laboratory tests on saline and non- saline soil samples. The results show that on saline soil samples, the Standard Error of Mean (SEM) of predicted ESP obtained by ESP-SAR model was (0.9389) and the P-value was (0.0572). On non- saline soil samples, the Standard Error of Mean (SEM) of predicted ESP acquired by ESP-SAR model was (0.2920) and the P-value was (0.2628). The statistical results indicated that the linear regression model (ESP-SAR model), ESP= 0.84 × SAR + 2.17 with R2 = 0.7347 has a good performance in predicting soil ESP from SAR meanwhile the ESP-SAR model reflected more accuracy on non- saline soil samples and it can be recommended for both saline soil and non-saline soil samples.