The Influence of Different Land Use Practices on Specific Physical Characteristics of Soil in Gaya, a Region within the Savanna Ecosystem in Nigeria

This study examines the impact of various land use types on specific physical properties of soil at the Kano University of Science and Technology Research Farm in Gaya, Gaya L.G.A., Kano State, Nigeria. The four agricultural land uses investigated are cropland, forest, grazing, and plantation land. Soil samples were randomly collected from two depths (0-15 cm and 15-30 cm), with five samples from each depth per land use type, resulting in 40 samples. Bulk densities were measured using the core method. The results indicated no significant effect (Fpr > 0.05) of land use on bulk density and porosity. However, bulk density values exhibited an increasing trend: cropland (1.602 g/cm3) < forest land (1.667 g/cm3) < plantation land (1.669 g/cm3) < grazing land (1.69 g/cm3). Grazing land had the highest mean bulk density, while cropland had the lowest. At 0-15 cm depth, plantation land had the highest mean bulk density (1.698 g/cm3), and cropland had the lowest (1.547 g/cm3). At a depth of 15-30 cm, forest land had the highest mean bulk density (1.767 g/cm3), while plantation land had the lowest (1.641 g/cm3). Total porosity showed an increasing trend from grazing land (30.8%) to plantation land (33.6%), cropland (34.3%), and forest land (37.7%). Factors such as organic matter content, aggregate size, and soil depth influenced the bulk density and porosity characteristics. Overall, bulk density was higher than standard values, indicating compaction: sandy soils were too compact, loamy soils were very compact, and clay soils were highly compact. Total porosity generally fell within the moderate range, and particle density was within the normal acceptable range of 2.65 g/cm3.