Soil organic carbon (SOC) and total nitrogen (TN) are key ecological indicators of soil quality in a given landscape. Their status, especially in drought-prone landscapes, is associated mainly with the land-use type and topographic position. This study aimed to clarify the effect of land use and topographic position on SOC and TN stocks to further clarify the ecological processes occurring in the landscape. To analyze the status of SOC and TN, we collected 352 composite soil samples from three depths in the uppermost soil (0–50 cm) in four major land-use types (bushland, cropland, grazing land, and plantation) and three topographic positions (upper, middle, and lower) at three sites: Dibatie (lowland), Aba Gerima (midland), and Guder (highland). Both SOC and TN stocks varied significantly across the land uses, topographic positions, and agro-ecosystems. SOC and TN stocks were significantly higher in bushland (166.22 Mg ha−1) and grazing lands (13.11 Mg ha−1) at Guder. The lowest SOC and TN stocks were observed in cropland (25.97 and 2.14 Mg ha−1) at Aba Gerima, which was mainly attributed to frequent and unmanaged plowing and extensive biomass removal. Compared to other land uses, plantations exhibited lower SOC and TN stocks due to poor undergrowth and overexploitation for charcoal and firewood production. Each of the three sites showed distinct characteristics in both stocks, as indicated by variations in the C/N ratios (11–13 at Guder, 10–21 at Aba Gerima, and 15–18 at Dibatie). Overall, land use was shown to be an important factor influencing the SOC and TN stocks, both within and across agro-ecosystems, whereas the effect of topographic position was more pronounced across agro-ecosystems than within them. Specifically, Aba Gerima had lower SOC and TN stocks due to prolonged cultivation and unsustainable human activities, thus revealing the need for immediate land management interventions, particularly targeting croplands. In a heterogeneous environment such as the Upper Blue Nile basin, proper understanding of the interactions between land use and topographic position and their effect on SOC and TN stock is needed to design proper soil management practices.

This study was carried out to evaluate microbial quality of raw cow's milk taken at different sampling points from farmers and dairy cooperatives in Bahir Dar Zuria and Mecha district. The overall mean total bacterial count, coliform count and percent lactic acid of milk produced in the study area were 7.58  0.09 log 10 cfu/ml, 4.49  0.11 log 10 cfu/ml and 0.23%  0.01, respectively. The hygienic quality of raw cow's milk of the dairy cooperatives was poor with an overall mean total bacteria count, coliform count and percent lactic acid of 8.12 log cfu/ml, 4.94 log cfu/ml and 28 percent, respectively. The overall mean of the predicted probabilities of clot-on-boiling and alcohol tests were 0.23  0.12 and 0.51  0.11, respectively. While, most of the milk samples collected from the dairy cooperatives were likely to clot both by clot-on-boiling and alcohol tests as compared to the samples collected from individual farmers. All the indirect tests and the actual bacterial counts indicated that the microbiological quality of milk produced by farmers and collected by the dairy cooperatives in the study area was poor and this call for scrupulous hygienic measures during production and handling of milk.

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Objective: Portable laser methane detectors (LMDs) may be an economical means of estimating CH₄ emissions from ruminants. We validated an LMD-based approach and then used that approach to evaluate CH₄ emissions from indigenous dairy cows in a dryland area of Ethiopia. Methods: First, we validated our LMD-based approach in Simmental crossbred beef cattle (n = 2) housed in respiration chambers and fed either a high- or low-concentrate diet. From the results of the validation, we constructed an estimation equation to determine CH₄ emissions from LMD CH₄ concentrations. Next, we used our validated LMD approach to examine CH₄ emissions in Fogera dairy cows grazed for 8 h/d (GG, n = 4), fed indoors on natural-grassland hay (CG1, n = 4), or fed indoors on Napier-grass (<i>Pennisetum purpureum</i>) hay (CG2, n = 4). All the cows were supplemented with concentrate feed. Results: The exhaled CH₄ concentrations measured by LMD were linearly correlated with the CH₄ emissions determined by infrared-absorption-based gas analyzer (r² = 0.55). The estimation equation used to determine CH₄ emissions (y, mg/min) from LMD CH₄ concentrations (x, ppm m) was y = 0.4259x+38.61. Daily CH₄ emissions of Fogera cows estimated by using the equation did not differ among the three groups; however, a numerically greater milk yield was obtained from the CG2 cows than from the GG cows, suggesting that Napiergrass hay might be better than natural-grassland hay for indoor feeding. The CG1 cows had higher CH₄ emissions per feed intake than the other groups, without significant increases in milk yield and body-weight gain, suggesting that natural-grassland hay cannot be recommended for indoor-fed cows. Conclusion: These findings demonstrate the potential of using LMDs to valuate feeding regimens rapidly and economically for dairy cows in areas under financial constraint, while taking CH₄ emissions into consideration.

This study was conducted to assess processing, utilization and marketing of traditional dairy products produced in Bahir Dar Zuria and Mecha districts in Northwestern Ethiopia. A single-visit-multiplesubject formal survey was conducted to collect data. A total of 150 households (75 households from each district) were individually interviewed using a semi-structured questionnaire. The major dairy products produced in the study area include butter, ghee, Ayib, Arera (defatted sour milk), Ergo (naturally fermented sour milk), Zure and Metata Ayib. Among these, two of the traditional dairy products, Zure and Metata Ayib, are unique to the area and have never been reported before. The respondents interviewed claim that these products are of high nutritional values and have therapeutic properties. Many aspects of Zure and Metata Ayib such as physico-chemical properties, microbiological and sensory qualities are unknown. Thus, detailed scientific investigation needs to be conducted in order to verify the claimed nutritional and medicinal properties of these products.