Abstract

Better understanding of how soils respond to land use is needed to enable science-based land management interventions. The present study investigated the relative changes in properties of ultisol under conventional tillage for arable crops and compared with fallowed plot (greater than 10 years of continuous no-till fallow) in the semi-humid Nsukka of southeastern Nigeria. Soil samples were collected from designated profile horizons for determination of soil properties. In cultivated plot relative to fallowed plot, soil erodibility increased by 2.5% (Ei + 0.11), total porosity decreased by 1.1%, whereas macro- and microporosity increased by 3.4 and 7.1%, respectively. Soil saturated hydraulic conductivity increased by 4.9%. The degree of topsoil saturation with water was similar in both the cultivated and the fallowed plots. Soil pH increased (7%) when exchangeable acidity increased (21.3%, +0.46 cmol (+) kg^-1). Losses of organic carbon (28%, -2.58 gkg^-1), total N (26%, -0.17 gkg^-1), available P (47%, -2.63 mgkg^-1), Ca (55%, -1.75 cmol (+) kg^-1), CEC (17%, -1.11 cmol (+) kg^-1), and base saturation (11.3 %) due to cultivation were observed. Since the fallowed plot that was previously under cultivation was able to show more favourable values of the measured soil properties than the cultivated plot without human activity, the study deduces that an ultisol can be resilient.

Key words: Ultisol, land use system, soil property, semi-humid, Nigeria.