In the limed system, where pHCa was above 4.0 in CaCl2, cropping systems induced a significant soil pH drop, well correlated with the export of alkali. The acidification rate of bare soil due to leaching was high and a cowpea–maize rotation did not significantly increase the rate, as the export of alkali was low. The introduction of stylo into the cropping system did not result in accelerated acidification when it was cultivated in rotations as the initial crop. However, when stylo was grown as perennial forage under a cut-and-carry system, with the objective of improving soil porosity, the acidification rate increased significantly.