Promising multipurpose three species and their response to land form on highland vertisols at Chefe Donsa, central highlands of Ethiopia

In Ethiopia acute household energy and feed demands have caused severe environmental and socio-economic threats. Multipurpose tree species have considerable role in addressing such multifaceted demands in the mixed crop-livestock production systems. However, physical and chemical soil properties should be conducive enough for their adequate growth performance. The cracking, selling and waterlogged nature of vertisols, is one of the major constraints for successful establishment and growth performance of several tree species on this frequent soil type. Thus, 18 potential multipurpose tree species of Leucaena, Sesbania, Acacia, Erythrina species and/or their accessions were evaluated on vertisols at Chefe Donsa for two years (1998-99) on flat and broad beds. Significant differences (P £ 0.05) were found in height, collar diameter and survival of the multipurpose tree species. In general, Sesbania species had significantly (P = 0.05) higher survival and growth in collar diameter and height than the others. Further, Sesbania sesban accession that originated fro north Ethiopia was found to be the best accession with significantly (P £ 0.05) better survival and growth in collar diameter and height than the others. Despite that, use of broad beds significantly (P = 0.05) improved the survaval of most of the Leucaena species. This performance could enable some of the Leucaena species to be promising for long-period production. However, Sesbania species and/or accessions planted on flat seedbeds had significantly (P = 0.05) lower collar diameter and height growth than those planted on broad beds. This could be due to drainage of excess moisture through furrows of the broad beds. This could have caused subsequent relative shortage of water for fast growing trees like Sesbania during the dry season. In general, Sesbania sesban accession that originated from northern Ethiopia needs to be further verified and demonstrated on-farm in Gimichu area for homestead and other farmers' plantation schemes on flat beds. In addition, in using broad beds for growing perennials like multipurpose tree species on vertisols, its potential for conservation of moisture and the genetic response of the species and/or accessions to drainage should be critically considered. Accordingly, use of broad beds has a potential for successful establishment of Leucaena species at Chefe Donsa