COMPARISON AND EVALUATION OF SIX ANALYTICAL METHOD FOR CHARACTERIZATION OF FIVE SOIL TYPES IN CENTRAL SUDAN

Abstract

Five areas in Sudan were selected which included; Gedaref area, Soba area, Wad Medani area, Nile river flood plain, and Shambat area. One soil profile was dug in each area, profile where morphological description was carried out for different horizons. Soil samples from each of these areas were collected and sent to laboratory Chemical and physical studies. The Samples were analyzed using two different methods described by (Bower, 1952) and (Mario and Rhoades, 1977) to determine Cation Exchange Capacity (CEC) and Exchangeable Sodium Percentage (ESP). Two different methods to determine CaCO3 (Titration and Calcimeter methods), Also two other methods (pipette and hydrometer) were used to detect soil particle size distribution to identify the best, and fast methods for laboratory soil analysis. Soil textural triangle was used to describe soil texture compared with soil texture computerized method. The results obtained showed the following; In Gedaref study area the soil is non saline, non sodic, and calcareous. Soba study area the soil is saline-Sodic and calcareous. Hence in Wad Medani study area the soil is non-saline at the depth 0-84cm, and slightly saline at the bottom depth 84-150cm, sodic and slightly calcareous. The soil of river Nile Flood Plain is non-saline, non-calcareous and non-Sodic, whereas Shambat area soil is non-saline to depth 0-83cm, and slightly saline at the bottom depth 83-150cm, sodic and slightly calcareous. The result revealed that (Mario and Rhoades method, 1977) is practical, simple and reliable for determination Cation Exchange Capacity (CEC) than the currently used (Bower method 1952). The calcimeter method is faster and more accurate than the titration method in measuring calcium carbonate. The pipette method is the better and accurate than the hydrometer method for soil textural detection. The use of the computerize soil particle size distribution detection is far better and faster than the manual soil textural triangle method.