Soil grouping of the Federal University Technology, Minna, Main Campus, Using Infiltration Rates.

Abstract

Different types of soil under different land use system were measured using double ring infiltrometer. After prolonged wetting (2 hrs), the nature of the soils, were determined with these final infiltration rates. The descriptions of soils were then grouped into four infiltration group of sandy, loamy, silt and clay soils. Under the fallowed land use practice, it was discovered to have higher volume of infiltration rate (5.80-46.20cm/hr) while under cultivated land practice (2.40-62.70cm/hr). However, the influence of land use on volumetric water content was not statistically significant which could be attributed to the clayey nature of the soils in the site, which masked the effect of land use. Regression analysis was performed on final infiltration as a function of bulk density, field capacity and initial moisture content. It was discovered that the surface bulk density had the highest correlation coefficient and average soil property down the profile which do not affect infiltration rates. Curve fitting was carried out on Phillip’s, Horton’s and Kostiakov’s models, which showed that Horton’s equation had a great consistent deviation during the early part of the test but Phillip’s equation started deviating during the later part of the tests, particularly for swelling soils. Kostiakov’s equation gave a more accurate result and is recommended for the soils tested and other similar soils.