CHANGES IN SOIL PROPERTIES OF A NEWLY-CLEARED ULTISOL DUE TO ESTABLISHMENT OF HEDGEROW SPECIES IN ALLEY CROPPING SYSTEMS

This study was initiated to evaluate the short-term ( < 3 years) abili ty of some selected acid-soil adapted hedgerow species when planted in alley cropping systems to improve soil properties in a newly-cleared Ultisol (Typic Kandiudult) of southern Cameroon. 1990-92. The hedgerow species selected were Senna (Senna spectabilis), Flemingia (Flemingia congesta) and Acioa (Acioa barterii). A non-alley-cropped control was also included in the trial. The greatest quantities of prunings, and hence, mulch were produced by Senna and Flemingia. Exchangeable Ca, ef fective CEC and water infiltration were greatly increased in the alley s of plots where either Flemingia or Senna had been planted within 2.5 years of hedgerow establishment. The large amounts of mulch produced by Senna and Flemingia did, however, result in soil temperatures great er than those of the control or Acioa plots c. 1 year after applicatio n of the prunings as mulch. Root growth of Senna in the subsoil was si gnificantly greater than that of either Acioa of Flemingia, but that o f cassava was reduced by alley cropping with all three hedgerow specie s. Compared to the control or alley cropping with Acioa, maize and cas sava yields were greater when alley cropped with either Flemingia or S enna hedgerows.