Hydrometer method against Pipette method for Estimating Soil particle size distribution in Some Soil Types Selected from Central Sudan

Abstract

Assessment of hydrometer against standard pipette methods for particle size measurements has been investigated in twenty-six soil samples collected from different climatological and ecological regions in central Sudan. Soil particle size distribution was determined using the two different methods in an attempt to insure that if the hydrometer method is accurate for particle size measurement for the soils of Sudan or not. The statistical analysis revealed that there are no significant differences (P > 0.05) between the two methods in most studied samples, except in clay and sand contents in the samples from 1st and 2nd Nile River terraces were significantly different (P < 0.05). These could be attributed to differences in the soil parent material, as indicated by increases in the clay and sand contents. Regression analysis between the two methods produced coefficient of determination (r2) values of 0.99 and 0.98 for clay and sand contents, respectively. Depending on the study findings, we conclude that, hydrometer method is somewhat less accurate in the sand measurement as compared to the pipette method; however, it can use it instead of pipette method for determining the soil texture for the soils of Sudan.