Soil Profile Characteristics As Affected By Land Use Systems In The Southeastern Adamawa State, Nigeria

The success of soil management to maintain soil quality depends on an understanding of how soils respond to agricultural use and practices over time.As a result, the important soil quality indicators were assessed under different land use systems to provide base line data for future research in Southeastern Adamawa State, Nigeria.The different land use systems were the cultivated land, natural fallow land, Gmelina plantation, pasture and the undisturbed natural forest land.One soil profile was opened in each land use system for field descriptions and laboratory studies in 2012/2013.The soil physical properties such as structure, colour, particle size distribution and soil depth characteristics showed notable variations due to different land use system, particularly in the surface horizons.The soil textures ranged from clay loam in the cultivated land, pasture land, undisturbed natural forest to sandy clay in the Gmelina plantation and sandy clay loam in the natural fallow land.The soil pH measured in water of the cultivated land, pasture, undisturbed natural forest and natural fallow lands varied from moderately acid to slightly acid in the Gmelina plantation.The OC and the total N decreased consistently from the surface to the subsurface horizons in all the land use systems.The surface horizons of the undisturbed natural forest, Gmelina plantation and the pasture land recorded the highest amount of OC/TN compared to the cultivated and natural fallow lands.This implies that intensive cultivation significantly deplete OC and TN.There was great variation in cation exchange capacity (CEC) of the soils under the different land use systems both in the upper and subsurface soil horizons.The CEC decreased almost inconsistently from the surface to the subsurface horizons in all the different land use systems.The decrease in CEC with depth could be attributed to a decrease in organic matter content with soil depth.Therefore, the depletion of organic matter as a result of intensive cultivation has reduced the CEC under the natural fallow and cultivated lands surface horizons respectively.