http://ir.bdu.edu.et/handle/123456789/1694 Sat, 13 Jan 2001 07:33:44 GMT 2001-01-13T07:33:44Z http://ir.bdu.edu.et/handle/123456789/11845 PETROLOGY AND GEOCHEMISTRY OF VOLCANIC ROCKS AND ASSOCIATED MAFIC DYKES IN THE BIRSHELEKO AREA, NORTHWESTERN ETHIOPIAN PLATEAU KIDIST TESFA This study is conducted in the Birsheleko area, NW Ethiopian plateau. The main aim is to determine the Petrogenesis of volcanic rocks and associated mafic dykes. To accomplish the research objective field investigation, petrographic and major and trace element geochemical analysis using a combination of ICP-MS and ICP-AES methods was applied. The lithological units identified in the study area are basalt, scoria cones, dolerite, and basaltic andesite. Basaltic andesite and dolerite are exposed as a dyke, besides; basaltic units cover most of the study area. The studied samples are characterized by aphyric to porphyritic texture with a variable proportion of plagioclase, olivine, and pyroxene as phenocryst. The groundmass is composed of plagioclase, olivine iron-titanium oxides (opaque minerals), clinopyroxene, and orthopyroxene. Based on the modal analysis the rocks are divided into pyroxene phyric basalt, Olivine phyric basalt, plagioclase phyric basalt, plagioclase phyric dolerite, and aphyric trachy flow basalt and basaltic andesite. Most of the studied samples fall into the tholeiitic group, however; two samples were grouped into transitional and alkaline groups. From the Harker variation diagram, most of the major and trace elements did not show a clear trend instead they are scattered suggesting the compositional variation of the studied rocks cannot be explained in terms of fractional crystalization. In the primitive mantle normalized multi-element diagram the tholeiitic samples show depletions in Rb, Th, Ce Pr, P, and Nb and prominent peaks at Ba, K, Pb, U, and Sr. However, the transitional and alkaline basaltic rocks show enrichment in Pb, Sr, Nb, Ba, depletion in Sm, Pr, without and the positive anomaly at U and K. This indicates that the tholeiites might experienced crustal contamination and the alkaline and transitional basalts are not From (Gd/Sm) N vs. (La/Sm)N diagram, it is determined that all the studied tholeiitic samples are formed by the melting of the spinel peridotite mantle source at a high degree of partial melting and shallow depth. In the contrast, the transitional and alkaline basalts are formed by the melting of the garnet peridotite mantle source by a low degree of partial melting at a greater depth than the tholeiites. Keywords: Crustal contamination, Degree of partial melting, Geochemistry, Northwestern Ethiopian plateau, Petrography Mon, 11 Jan 2021 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/11845 2021-01-11T00:00:00Z http://ir.bdu.edu.et/handle/123456789/11834 CONTRIBUTION OF DIRECT SEED MARKET FOR THE AVAILABILITY AND ACCESSIBILITY OF QUALITY MAIZE SEED IN GUANGUA WOREDA, AWI ZONE, AMHARA REGION. Shumete Erena Quality seed utilization enhances high production and productivity thereby improving farmers` food security and livelihood. Seed availability, quantity, and affordability contributes a great role to agricultural production and productivity. To address these demands, efficient and responsive seed marketing and distribution supply chain system are required. This in turn call for an integrated assumptions and approaches among all the stakeholders (partners) in the seed sectors and systems. The principal aim of this study is to explore the contribution of direct seed marketing for the availability and accessibility of quality seed in Amhara region, Guanegua woreda, and determine its responsiveness and efficiency to meet farmers` demand. Both primary and secondary data sources were used. To glean valid and reliable data, two stage sampling procedure had been used to select one Wereda and three kebeles. For the survey, questionnaires were prepared and administered to random sampled households. Key informants were purposively selected from institutions like bureau, Integrated Seed System Development, Agricultural Transformation Agency, Seed producers which are the main actors in the value chain. The quantitative and qualitative data were collected from149 household heads and 12 key informants and quantitative data were analyzed mainly using descriptive statistics (likert scale, tabulation, percentage and graphs); while qualitative data were summarized through narrative accounts and interpreted. The results showed that DSM system improved the seed supply as well as use by creating more access in the study area. Now days, farmers in the study area are satisfied with DSM system except the price of seed. So, DSM contributed a significant role to solve farmers’ problem in accessing improved maize seed while some challenges encountered with lack of store, less road accessibility and unfair market competition is observed. Involving more agents and capacitating seed producers are important to enhance the value of DSM more. Keywords: Accessibility, Availability, direct seed marketing (DSM), Quality seed Tue, 05 Jan 2021 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/11834 2021-01-05T00:00:00Z http://ir.bdu.edu.et/handle/123456789/11832 ASSESSMENT OF SEED DISTRIBUTION SYSTEM OF BREAD WHEAT (Triticumastivum L.) IN ENEBESIE SAR MEDER DISTRICT, NORTHWEST ETHIOPIA Tiliksew Abebe Seed is a vital input to improve agricultural production and productivity. Farmers obtain seed from both formal and informal seed distribution system. The informal seed sector is the major seed supplier in Enebsie Sar Meder District. Because, access to the formal seed sector is limited for the farmers. So, this research tried to assess the seed distribution system of bread wheat seed in Enebsie Sar Meder District Northwest Ethiopia. The objectives of this study were to analyze seed distribution system of bread wheat seed, to identify the challenges of the current seed delivery system and to analyze determinants of smallholder farmers in selecting seed of bread wheat distribution system. The study was based on the data collected from 150 households using multistage probability sampling method. In line with this, the combination of data collection methods of self-administered interview questionnaires and key informants interview and focus group discussion were conducted. The binary logit model was used to analyze determinants of selection in seed distribution system of bread wheat in the study area. The result of logit model showed that six variables significantly influenced selection preferences of of formal seed distribution system. Level of education, access to credit, household income, extension services and seed quality significantly and positively influenced farmers’ selection of formal seed distribution system. Whereas distance to the nearest seed distribution center influenced negatively and significantly the selection of formal seed distribution system in the study area. Any concerned organ should look a due attention to the important variables to support farmers for proper seed distribution systems of bread wheat seed and enhance production. Keywords: Bread wheat, Distribution system, Enebsie, Logistic regression model, Seed Tue, 05 Jan 2021 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/11832 2021-01-05T00:00:00Z http://ir.bdu.edu.et/handle/123456789/11831 Farmers’ Perception and Factors Affecting their Decision to Use Improved Maize (Zea mays) Seed: In Case of Wonberma Districts, Amhara National Regional State, Ethiopia Kidist Meseret Maize (Zea mays L.) is one of the most important cereal crop in production and area coverage in Ethiopia. However, farmers from different agro-ecology faces various problems to increase production and productive of the crop. It is therefore, imperative to consider attributes that are preferred by farmers in developing maize seed varieties. The aim of this study was to investigate farmer’s perception and the factors affecting their decision to use improved maize seed variety: In case of Wonberma Woreda, Amhara, Ethiopia. The study used data that was collected in Wonberma district in which 240 maize produced farmers were selected by using simple random sampling technique. Both qualitative and quantitative data were collected from primary and secondary sources. Household survey, key informant interview of sample farmers and focus group discussion were the means used to collect the data. The study used descriptive statistics such as mean, standard deviation, frequency, percentage and inferential statistics such as t-test, and chi-square test methods for data analysis and a binary logistic (logit) regression technique is used to analyze data objectively in order to answer the study questions. The total number of respondents was 240, out of these 197 respondents were improved maize seed users and 43 respondents were improved maize seed non-users. The results revealed that seed price, family size, distance to market, farm size and extension services have a statistically significant contribution to promote farmers’ choice of improved maze varieties. Further, high yield, early maturity, tolerant to drought, and resistant to pest and diseases were the major criteria used by farmers to make decision on utilization of the variety. The findings suggest that the high importance of socio-economic, Tue, 05 Jan 2021 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/11831 2021-01-05T00:00:00Z