Grazing management and seasonality strongly influence the recovery potential of herbaceous vegetation in semi-arid rangelands of southern Ethiopia after history of heavy grazing. We investigated effects of management (enclosures versus grazed landscapes), age of enclosures and seasonality related to rainfall (i.e., independent variables) on herbaceous biomass, grass basal cover, herbaceous species abundance, species richness and diversity in a savanna rangeland of southern Ethiopia. We further assessed the relationship between the herbaceous biomass and species richness. Management significantly affected most of the herbaceous response variables (i.e., comparing enclosures and open grazed). Herbaceous biomass, grass basal cover, herbaceous species richness and diversity were greater in enclosures than in grazed areas. Rainfall was also influential on herbaceous biomass, grass basal cover, abundance of herbaceous species, herbaceous species richness and diversity. Herbaceous biomass, abundance and diversity did not however vary with the age of enclosures, while herbaceous species richness appeared to decrease as the age of enclosures advanced. Grass basal cover initially decreased and later on increased with the age of enclosures, so that the older enclosures disclosed improvement of grass basal cover.

The growth response of Tilapia fish (Oreochromis niloticus) to supplementation with fresh or dried leaves of a sweet variety of cassava was studied in 1 m deep ponds (each 4 m * 2.5 m * 1 m). Rice bran or rice bran mixed with cassava root meal was provided as the energy source (20-24% of feed DM), the mixed feed being given at the rate of 5% of fish LW. There were 30 fish per pond with average initial weight of 6 g per head. The treatments were arranged as a 2*2 factorial in a Completely Randomized Design (CRD) with 4 replicates. The first factor was cassava leaf processing (sun-dried or fresh); the second factor was energy source (rice bran or rice bran mixed with cassava root meal). The cassava leaves and roots were from a local “sweet” variety traditionally planted by farmers for human consumption. The experiment was conducted for 100 days. Daily gain in weight and length, and the ratio weight: length after 100 days of growth, did not differ among treatments. All the fish survived and there was no evidence of HCN toxicity. Water quality parameters were not affected by the treatments. There were no interactions between sources of protein and of energy. It is concluded that the feeding of cassava leaves with rice bran can be readily adopted by small scale farmers as both these feed resources are readily available in rural areas.

A survey was conducted in Hamer and Benna-Tsemay districts of the South Omo zone of Ethiopia, with the objectives of assessing the range-livestock management practices and perceptions of the different pastoral groups (Hamer, Benna, and Tsemay) towards rangeland degradation. This information is considered to be vital to future pastoral development planning and interventions. The information was gathered through group discussions, personal observations, and using a structured questionnaire where each household was taken as a unit of analysis. The average family size per household was for Hamer = 7.05 for Benna = 7.93 and for Tsemay = 7 with nearly 98.1% of the respondents without any kind of education. All pastoral groups derived their main income from the sale of animals, which was followed by the sale of honey as in the case of Hamer and Tsemay pastoralists. The average livestock per household was 25.7, 10 and 2.8 tropical livestock unit (TLU) cattle, goat and sheep, respectively. The major livestock production constraints were drought, feed and water shortage and animal health problems. The different pastoral groups have the opinion that the condition of their rangeland is poor, mainly due to overgrazing, drought and increase in human population. Furthermore, there was also a problem of bush encroachment which is an indicator of rangeland degradation. There are no range improvement practices undertaken to improve the condition of the rangelands. Mobility is the first measure taken to solve shortage of livestock feed and water but many of the pastoralists replied that they face many problems during migrations. Because of the unfavorable climatic condition for cultivation, most of the respondents of Hamer and Tsemay pastoralists and about 35% from Benna still prefer communal land tenure, where resources are shared. In conclusion, the indigenous knowledge of the pastoralists about range-livestock management and their environment should be incorporated while planning range-livestock development projects for the study districts.

A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and grazing types. In the study districts, a total of 32, 3, 2, 7 and 29 species of grasses, legumes, sedges, other herbaceous plants and woody species were identified, respectively. The common and/or dominant grass species in the enclosures was Cenchrus ciliaris while in the communal grazing areas they were Cynodon dactylon and Tetrapogon tennulis. In riverside grazing areas, the common and/or dominant grass species was Cynodon dactylon. The total grass biomass of communal, riverside and enclosure areas found in the different altitude categories of the study districts ranged from 398-503; 98-626, and 1,132 – 1,209 kg/ha, respectively. The common and/or dominant woody species in the communal grazing areas were highly palatable species of Acacia tortilis and Grewia bicolor and less palatable Solanum species. In riverside grazing areas, the common and/or dominant woody plants were species of Acacia tortilis, Grewia bicolor, and Solanum species while in the enclosures; Acacia brevispica and Acacia tortilis were found. The woody vegetation density per hectare of communal, riverside and enclosure areas in the different altitude categories of the study districts ranged from 2,501-3,021; 2251-3,021, and 201-700,wd/ha respectively which showed that the communal and riverside grazing areas were bush encroached. The range condition scores ranged from 17.87-20.38 (communal), 22-27 (riverside), 31.05-31.2 (enclosures) which were poor, fair and good condition classes, respectively. Similarly, with regard to the same variable the scored varied from 22-32.87, 19.73-31.43, 17.97-31.44 and 17.87-31.28% in altitudes >1550m, 1250-1550m, 900-1250m, and 550-900m, respectively. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands

This paper analyses food consumption in rural households of forest zones. Based on a panel survey of 80 households in Cameroon, expenditure-elasticities of demand for roots and tubers are estimated and compared with those of other staples. Yam and cassava are the two most important root and tuber crops grown in Africa. The expenditure elasticity estimates for yam revealed that the domestic market potentials are high in forest zone for this crop, while in the case of cassava, it was established that the extent to which the potential market will be expanded, would depend on which degree the quality of the dry products can be improved