The application of a vegetative mulch had no significant effect on maintaining and prolonging the soil structure (measured as porosity and bulk density) obtained from tillage on a heavy clay soil. Mulching, however, had positive effects on soil moisture conservation and lowering of supra-optimal soil temperatures, the soil moisture conservation being beneficial when mean weekly rainfall is normally low. It can, however, be detrimental when rainfall is high, as the soil has very poor internal drainage. Mulching no-tillage plots showed some build up of N and organic C in the 0-5 cm soil depth. Increased cowpea yields under mulch indicate that this could be a viable practice for the short rainfall period. For the long rainfall period the use of mulch cannot be strongly recommended.