Sesbania sesban, a fodder species potential to rehabilitate wetland vegetation in Lake Ziway, Ethiopia

Abstract

Wetland vegetation have significant roles in buffering effects of agro-chemicals and a mass of eroded soil entering in to lakes. Buffering wetland vegetation in the shore of Lake Ziway, a Lake in the Ethiopian mid-Rift Valley with 137 km shore length and 434 km2 area supporting over 4,600 livelihoods in fisheries activity, is threatened by anthropogenic impacts in the semi-arid, drought stressed surrounding. A pre-test experiment was done to evaluate multipurpose, three fodder plant species, elephant grass, Sesbania sesban and Leucaena pallida in their potential to re-habilitate a degraded wetland around Lake Ziway. The planting materials of elephant grass and seeds of Sesbania sesban and Leucaena pallida were planted in a selected littoral zone of the Lake during June 2009, after which they were protected by fencing and let to grow. All of the three species were well established during the first season. However, Leucaena pallida and elephant grass were dry out after August when the Lake’s water level increases and inundate the area. Being submerged partially under water, Sesbania sesban tolerated the inundation caused by the rise of water level in the late rainy months and developed a mass of adventitious roots from the stems which mechanically trapped the incoming eroded soil from the immediate farm lands. Very dense grass of height up to 1 m, established in the protected area around the experimental plots was also the indication of the rehabilitation of wetland vegetation for its better buffering capacity. The Sesbania sesban, multipurpose plant and the established grass, potentially provides a high protein source green roughage to livestock in this drought affected Rift Valley area.