Alley cropping of maize with calliandra and leucaena in the subhumid highlands of Kenya: Part 2. Soil-fertility changes and maize yield

摘要: Although N-rich leaf biomass of multipurpose trees is known to be a good source N crops, integrating such into crop production systems major challenge in the development viable agroforestry systems. An approach calliandra (Calliandra calothyrsus Meissner) and leucaena (Leucaena leucocephala (Lam.) de Wit), two promising tree species, maize (Zea mays L.) system was investigated subhumid highlands central Kenya during four maize-growing seasons from 1994 1996. The experiment consisted plots which prunings obtained hedgerows grown either situ (alley cropping) or ex (biomass transfer outside) were applied. When alley-cropped with leucaena, produced significantly higher yields compared monoculture (both non-fertilized fertilized) treatments, but when calliandra, yield less than that monocropped unfertilized control. Application without fertilizer resulted grain nonfertilized fertilized treatments. Yields alley- cropped 11% 51% lower those nonalley-cropped treatments receiving trees; decrease 2% 17% indicating hedges more competitive hedges. prunings-removed lowest yields. study showed that, tropical Kenya, inclusion on cropland adversely affected On other hand, alley cropping advantageous.