Physical quality of Northern Nigeria Savanna Alfisol: Influence of Jatropha curcas L. and other land use systems

Abstract

This study investigated the impact of three adjacent land use systems [land under arable cropping (ARL), cattle grazing fallow (GFL) and Jatropha curcas L. Orchard (JCL)] on selected soil physical quality indicators in a Northern Nigeria Savanna Alfisol. GFL had significantly higher organic carbon content (26.2–32.1% higher) and bulk density (4.5–9.2% higher) than JCL and ARL respectively. Higher bulk density (ρb) in GFL aided by trampling induced compaction resulted in its high relative field capacity (RFC), permanent wilting point (PWP) and micro-pore spaces (PMIC). Continuous tillage in ARL created loose soil in the plough layer (<20 cm) which turn out to its low bulk density (ρb) and high plant-available water capacity (PAWC), total pore spaces (f) and macro-pore spaces (PMAC) over JCL and GFL. Total nitrogen content, dry stability of large macro-aggregate fractions [5–2 mm, (LMag)] and mean weight diameter (MWD) were higher in JCL than GFL and ARL to about 47.2–60.6, 12.5–68.8 and 8.57–44.76%, respectively. This showed some possibilities of JCL in improving the nitrogen content and stability of soil. Yet, long term studies on the impact of J. curcas L. on the soil quality are needed in order to evaluate if such possibilities are sustainable or not.