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Abstract Recycled engine oil was produced from used engine oil (15W-40) using a combination of MEK and 1-butanol solvents with an activated carbon adsorbent through the adsorption process. The experimental design matrix was prepared using Box-Behnken design (BBD) package within RSM, and recycled engine oil is optimized by response surface methodology (RSM). By varying solvent-to-oil ratio, the temperature and contact duration optimal conditions were identified as a 5.5:1 MEK and 1-butanol solvent-to-oil ratio, 50 min of contact, 42.5 °C, and constant 1 g of activated carbon adsorbent, yielding (65.20%, 65.20%) numerically and experimentally, respectively. Process factors (solvent-to-oil ratio, the temperature, and contact duration) influencing the yield of recycled engine oil are indicated by both contour and surface plots. The characterization of recycled oil indicates that its physiochemical properties, such as density, viscosity, flash point, pour point, and total base number, met the ASTM standards. GC–MS analysis further identified the presence of natural base oil, additives (polymeric, metallic, and non-metallic), and oxidation compounds, indicating the efficacy of the recycling process in recovering valuable components from the used engine oil. Before and after adsorption, FTIR is used to analysis the effect of optimized engine oil adsorption on the activated carbon adsorbent. The recycling method that has been optimized indicates potential for sustainable resource consumption and conservation, which may help the vehicle industry practice environmental stewardship.

Biodiesel (methyl ester) was synthesized from cottonseed oil (CSO) with methanol in the presence of an alkali catalyst (KOH) through the transesterification method. Response surface methodology (RSM) optimized the methyl ester synthesis process. The experimental design matrix was arranged using the Box-Behnken Design (BBD) of RSM. The optimization of methyl ester was achieved by varying variables such as the methanol to CSO ratio, the concentration of the catalyst, and the reaction duration. A contour plot and a surface plot were generated to illustrate the impact of these variables on methyl ester synthesis. The biodiesel yield was modeled as a quadratic equation through RSM analysis, with a coefficient of determination (R2) and adjusted R2 of 0.97 and 0.968, respectively. The optimized CSOME yield (95.04%) was numerically gained at a 1:6 methanol to CSO ratio, a reaction duration of 52.2 min, and a 0.985 wt% catalyst concentration. Based on these parameters, a 94.80% CSOME yield was experimentally obtained. This shows that response surface methodology (RSM) is sufficient for optimizing methyl ester yield. The produced methyl ester was characterized to determine its physicochemical properties. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the specific type and proportion of fatty acid esters present in the CSOME. The main types of fatty acids found in CSOME were methyl 9-cis 11-trans-octadecadienoate (C18:2), hexadecanoic acid methyl ester (C16:0), 11, 14-octadecadienoic acid methyl ester (C18:2), methyl 8, 9-octadecadienoate methyl ester (C18:2), and myristic acid methyl ester (C14:0).

Terminal drought and lodging are among the major yield-limiting factors for tef cultivation in the highly weathered soils of the Ethiopian highlands. Therefore, a study was conducted to assess the yield and lodging responses of tef to varying moisture depletion levels (MDL) and the application of carbonized rice husk (CRH). A two-year 4×4 factorial experiment with 20, 35, 55, and 75% MDL and 0, 291, 582, and 873 kg ha-1 of CRH was laid out in a split-plot design, with each treatment replicated four times. The pooled mean ANOVA showed leaf area index (LAI) and lodging index (LI) were not significantly influenced by the main and interaction effects of MDL and CRH (p > 0.05); however, individual year ANOVA showed that both LI and LAI were influenced by the interaction of MDL and CRH (p

Even though CI engines are more efficient than SI engines due to their ability to operate at a greater compression ratio, a leaner charge, and lower throttle losses, they have higher PM and nitrogen oxide emissions. The induction system modification with fuel port injection is used as a parameter in RCCI engine operations for controlling emission through in-cylinder charge reactivity and combustion phasing. By varying the amount of hydrous bioethanol in the premixed fuel injection ratio, the engine’s performance and emissions are greatly affected. In this study, an experimental investigation of a triple-fuel RCCI engine running on port-injected gasoline-bioethanol blend and direct-injected diesel fuel was conducted. Taguchi’s experimental design method was employed to assess the impact of various independent variables utilizing three set levels and two factors with the L9 orthogonal array. From the findings, the delta value shows the highest average response for each factor. Engine speed has the largest effect on the signal-to-noise ratio (SNR) with the (delta value of: 10.7446, rank = 1), and the delta value of 38.96, rank = 1, has the largest effect on the response of means at engine speeds of 3000 rpm. The premixed fuel ratio of G25BE75 (delta: 87.30, rank = 1) has the largest effect on the standard deviation. The lines are not parallel in all emission and performance cases except for Tb and CO2, which are close to parallel. The best means in engine speed and premixed blended fuel ratio were NOx, CO, HC, and brake power. At 3000 rpm, the speed had the larger main effect plots of SNR. The premixed fuel ratio of G25BE75 had higher main effect plots for means and standard deviations. The residues appear to have been dispersed normally based on a straight line by using a normal probability plot. The data are normally distributed, as demonstrated by the normal probability plot, and the factors had an impact on the response. Conferring to the experiment result, a high engine speed and higher ethanol content in the RCCI premixed fuel are preferred for reducing nitrogen oxides (NOx) and carbon dioxide (CO2), while unburned hydrocarbons (UHCs) and carbon monoxide (CO) showed a slight increase.

Lodging, poor crop varieties and nitrogen management are among the main tef cultivation problems in acidic soils of northwestern Ethiopia. Though Si has been shown to improve crop yield and lodging resistance, knowledge of its effect on tef, along genotypes and nitrogen, is yet to be uncovered. Therefore, a 4 × 2 × 2 factorial field experiment was conducted on fixed experimental plot at the Koga irrigation scheme to assess yield and lodging responses of tef varieties to nitrogen and silicon fertilizer rates during two consecutive years of 2021 and 2022. The experiment comprised four nitrogen levels: 0 (N1), 23 (N2), 46 (N3), and 92 kg N ha−1(N4), two Si levels: 0 (Si1) and 485 (Si2) kg ha−1, and two improved varieties: Hiber-1 (V1) and Quncho (V2) treatment combinations, which were replicated four times. Results showed that regardless of silicon supply and variety, nitrogen had a significant effect (p < .0001) on agronomic attributes of tef grain yield, biomass yield, harvest index, chlorophyll content, plant height, panicle length, leaf area index, and the number of plants m−2 over the two years. Application of N4, N3, and N2 improved grain yield by 166.9, 126.2, and 75.2 % over N1, respectively. The harvest index showed a declining trend with nitrogen rates, which ranged from 36.1 to 26.5 %. Hiber-1 showed a significantly (p < .01) higher panicle length than Quncho. The interaction of nitrogen, silicon, and variety significantly (p < .001) affected lodging index, with a minimum lodging index of 0 % from V1Si1N1 and a maximum lodging index (71.9 %) from V2Si1N4. Maximum net return (2552.6 USD) was obtained from V1Si1N4, while the marginal rate of return (6961.7 %) from V1Si1N3. Therefore, it can be concluded that genotype and optimum nitrogen can maximize yield and lodging resistance of tef, while silicon in the form of carbonized rice husk results no significant effect on tef lodging.

To satisfy customers, the quality of watermelon should not deteriorate throughout the value chain. Hence, this study aimed to evaluate the effects of storage alternative (plastic shade, zero energy cool chamber, naturally ventilated onion storage, and ordinary storage room), storage duration (1 st, 2nd, 3rd 4 th, and 5th -weeks), and variety (Crimson-sweet and Sugar-baby) sampled from three locations with factorial combinations in completely randomized design (CRD) with three replications. Storage condition, duration, variety, and location influenced the quality attributes. The plastic shade and ordinary storage room maintained better TSS (total soluble solids) compared to the others. Crimson-sweet maintained better TSS, acidity content, and overall acceptability during storage. Regardless of storage conditions, variety, and location, TSS decreased while pH increased with prolonged duration. TSS below the US standard of 8% manifested after the 4th -week of storage. The ordinary storage room maintained sensory qualities the best. The overall acceptability of stored fruits was ‘neither like nor dislike’ according to the panelists after the 4th -week in all storage conditions. It is concluded that watermelon has a shelf-life of one month. Therefore, we recommend plastic shade and ordinary storage room, Crimson-sweet variety, and Ribb and Woramit locations, for the watermelon value chain in Ethiopia.

A two-year field experiment was carried out to scrutinize the integrated use of NPSZnB blended fertilizer and farmyard manure (FYM) on maize growth and yield components at Koga and Bachima villages in Mecha district and Geray and Jiga villages in Jabi Tehran district. Factorial combinations have five levels of NPSZnB (100, 150, 200, 250, and 300 kg·ha−1), and four rates of FYM (0, 12, 16, and 20 t·ha−1), plus one blanket recommendation (200 kg·ha−1 DAP and 150 kg·ha−1 Urea). A randomized complete block design with three replications was used to set up the studies. Except for days to silking and leaf area index at both locations, and days to physiological maturity, and ear length at Mecha, main and interaction effects on all parameters were detected at both locations. The only main effect of NPSZnB was detected on the harvest index at Jabi Tehnan. Generally, the results achieved from the interaction effect were better and greater than those obtained from the blanket recommendation although this was not the case for the main effects. Grain yields at Jabi Tehnan and Mecha were 5618.5 and 5421 kg·ha−1, respectively, as a result of the unified use of 250 kg·ha−1 NPSZnB and 20 t·ha−1 FYM and shortened days to 50% tasselling by 3.46 days and delayed 90% physiological maturity by 2.95 days than the blanket recommended fertilizer at Jabi Tehnan. As the main effect, compared to the blanket recommendation, 250 kg·ha−1 at Jabi Tehnan and 300 kg·ha−1 NPSZnB at Mecha reduced the days to 50% silking by 0.225 and 0.292 days, respectively. Contrasted with the conventional recommendation, the application of 300 kg·ha−1 NPSZnB minimizes days to 90% physiological maturity by 0.89 at Mecha, and the rise in FYM level from 0 to 20 t·ha−1 caused 0.832 and 0.279 extra days to reach 50% silking at Jabi Tehnan and Mecha, respectively. The yield had a very strong correlation that is positive with growth and yield components. Economic study: the use of 200 kg·ha−1 NPSZnB with 20 t·ha−1 FYM resulted in the maximum net benefit of 36221.06 and 35431.04 ETB ha−1 at Jabi Tehnan and Mecha, respectively. Thus, 250 kg·ha−1 NPSZnB with 20 kg·ha−1 FYM and 200 kg·ha−1 NPSZnB with no FYM application were the most acceptable rates at both locations with a low cost of production to small-scale farmers. For resource-rich farmers, 200 kg·ha−1 NPSZnB with 20 t·ha−1 FYM was also favorable, with the best net benefit at both locations.

AbstractIntercropping of cereals and legumes is common in Ethiopia. However, intercropping of lupine with tef is a new practice in Northwestern Ethiopia’s tef-based cropping system. In the 2016 and 2017 main cropping seasons, a field experiment was conducted in Gozamin District, East Gojjam Zone, to assess the effect of plant density of lupine intercropping with tef on the productivity of tef fields. The two experimental factors were two inter-row spacings (20 and 40 cm) and three intra-row spacings (10, 15, and 20 cm) of lupine intercropped with tef, and their factorial combination was studied using a randomized complete block design (RCBD) with three replications. The highest tef grain yield (1.80 t ha−1) was recorded from 40 and 20 cm inter- and intra-row spacing of lupine intercropped with tef, respectively. The highest lupine yield (2.74 t ha−1) was recorded from sole cropping. A total of 40 and 15 cm inter- and intra-row spacing of lupine intercropped with tef improved tef equivalent yield (2.32 t ha−1), area time equivalent ratio (1.09), actual yield loss (0.87), monetary advantage index (396.2 USD), net benefit (2479.5 USD ha−1), and marginal rate of return (MRR) (682%). Among all planting densities, 40 and 15 cm inter- and intra-row spacing of lupine were the most profitable and had the highest yield advantage based on equivalent yield and other economic benefits. To maximize the productivity of tef fields, 40 cm of inter- and 15 cm of intra-row spacing of lupine intercropping with tef was recommended.

Diesel engines are widely used due to their higher thermal efficiency and lower Hydrocarbon (HC) emissions. The price fluctuation of petroleum fuel; the none-renewability and different hazardous emissions from petro-diesel, researchers are searching for a suitable renewable energy source for diesel engine. Ethanol is one of the promising alternative fuels that could be used to power diesel engine. Some of the techniques so far tried are ethanol fumigation, dual injection and blending. The former techniques need different engine modification to enable the additional systems to work on the existing engines. Blending is the best technique to substitute the existing diesel fuel as long as we prepare it as per the current diesel fuel minimum requirement. For this specific case micro emulsion of ethanol in diesel fuel with emulsifier is prepared by using magnetic stirrer and bath type ultrasonicator. Nickel Zinc Iron Oxide (NiZnFe2O4) nanoparticle is added in one of the selected emulsion which is having 10% ethanol in three different dose as additive to see the effect on the performance and emission variation of the emulsion compared with diesel fuel. The performance of the prepared sample fuels are tested on a test rig with single cylinder diesel engine. The emission is measured by using exhaust gas analyzer and smoke opacity meter. The specific fuel consumption, brake torque and brake power of E5 (95% diesel and 5% ethanol), E10 (90% diesel and 10% ethanol) and E15 (85% diesel and 15% ethanol) are evaluated and the result showed 27, 34 and 37% increment in fuel consumption; 15, 5 and 15% reduction in brake torque and the power reduction is 19, 7 and 12% respectively. E10 is selected for further test with addition of the nanoparticle with 25, 50 and 100ppm named as E103N25 (E10 with 25ppm NiZnFe2O4 nanoparticle), E103N50 (E10 with 50ppm NiZnFe2O4 nanoparticle) and E102N100 (E10 with 100 ppm NiZnFe2O4 nanoparticle). The result showed fuel consumption reduction by 16, 27 and 27% torque output increment of 1, 2 and 2% and power output increment of 5, 7 and 7% respectively compared with E10. The emission result revealed that the HC emission reduced by 50, 58 and 71% for E103N25, E103N50 and E103N100 fuel samples respectively, Carbon monoxide (CO) emission reduced by 67, 80 and 81% for E103N25, E103N50 and E103N100 fuel samples respectively. The reduction in smoke emission is reduced by 60, 69 and 61% for E103N25, E103N50 and E103N100 fuel samples respectively. Nitrogen oxide (NOX) and Carbon dioxide (CO2) emissions increased with the amount of nanoparticle added in to the fuel.

In developing countries like Ethiopia, where the time of harvesting coincides with the dry season, farmers cure onion bulbs naturally on the field. Field curing generally takes longer than artificial curing and results in more losses and reduced quality of the bulbs due to increased risks for infestations and uncontrolled suboptimal drying conditions. Large-scale artificial curing systems are expensive and electrical energy supply is limited in rural areas. A CFD model was employed to design an alternative and sustainable onion curing system that can be deployed on the field in rural areas. The developed CFD model was validated by comparing the predicted air velocity, temperature, and mass loss to measured values on a prototype curing system operated on a field in Ethiopia. A good agreement between the model and experimental value was observed for the time profiles of temperature at different positions in the bulk of onions during curing, expressed by a root mean square error of 1.1°C in the temperature range from 28 to 47°C, 0.16 m s−1 in the velocity range from 0.1 to 2.5 m s−1, and 0.565% for the mass loss that ranged up to 6.35%. The developed model was used to assess the air velocity, temperature, and relative humidity distribution in order to get an insight into the uniformity of curing of onion bulbs using the develop alternative curing system. For all of the examined curing durations, the drying air temperature variation inside 80% of the porous medium was < 3°C. In the remaining 20% of the porous medium, a temperature variation of up to 6°C was observed. Thus, the newly designed and developed curing system was found to cure the onion bulbs uniformly. Moreover, its performance was evaluated experimentally and the onions were cured to a desirable level of curing for long-term storage within a total curing duration of 48 h. It is vital to consider bulb shrinkage, particularly in the neck, in order to further improve the model mass loss prediction.

Searching for ultra-low emission engines particularly for automotive applications is still ongoing. Even though LTC combustion mode results a prominent advantages in terms of reducing both NOx and PM and also lowering the consumption of fuel, it mainly faces with the challenge of excess emissions of HC and CO. This study aimed to optimize the operating control factors for low emissions in PCCI-DI engine under LTC mode. Parameters include injection timing, EGR level, dieseline ratio and engine load. Computation of analyzing the grey relation with hybrid of Taguchi was applied. In designing of experiments and conducting tests Taguchi's L9 matrix was applied. Air-blast of methanol intake port supply and dieseline application instead of diesel was implemented aiming emission reductions. Optimum combinations were found using GRA and ANOVA. Following the optimization work; advanced injection timing of 25o before TDC, 25% EGR, dieseline 90:10 in % and load 75 % (A2B1C3D3) was found optimal combination level for the proposed aim of emission reductions. Key findings of the results following the experiment conducted using this optimal combination includes; reduction of 68.02% NOx and 62.37% in smoke comparing with the base-line conventional diesel combustion mode. Rankings and ANOVA indicated another findings that injection timing being most influential with a contribution of 69.35% followed by load, dieseline ratio and EGR level respectively. This study confirmed dieseline direct injection with methanol port injection is capable of reducing emissions and better NOx with HC and CO trade-offs in PCCI-DI engines.

The application of optimal fertilizer rates for component crops improves productivity, land use efficiency, and profitability in an intercropping system. Two field experiments during the 2019 and 2020 cropping seasons were conducted in Adet and Debre Tabor districts with the objective of evaluating the nutrient requirements of sweet lupine in bread wheat-sweet lupine under additive design intercropping systems. Sweet lupine grown in bread wheat-sweet lupine intercropping was fertilized with seven fertilizer levels (0%, 25%, 50%, 75%, 100%, 125%, and 150% of the blanket-recommended NP fertilizer rate of sole lupine) and laid out in a randomized complete block design with three replications. The findings revealed that the highest grain yield of sweet lupine in wheat-sweet lupine intercropping system at Adet was achieved at 125% NP (0.51 t·ha−1) and 150% NP (0.52 t·ha−1), followed by 100% NP (0.43 t·ha−1) and 50% NP (0.35 t·ha−1) fertilizer levels of sweet lupine. Similarly, the highest grain yield of sweet lupine in Debre Tabor was recorded by the application of 125% NP (2.07 t ha−1) fertilizer level of sweet lupine followed by 150% NP (1.89 t·ha−1), 100% NP (1.71 t·ha−1), and 50% NP (1.70 t·ha−1) fertilizer levels. For every invested Ethiopian Birr in the treatments of 50% and 125% NP fertilizer levels of sweet lupine averaged additional profits of ETB 7.667 and ETB 4.537, respectively, can be obtained from sweet lupine that grew under bread wheat-sweet lupine intercropping system. Based on the averaged MRR across the different cost price ratio, application of 50% NP fertilizer level of sweet lupine can be recommended for profitable production of sweet lupine in bread wheat-sweet lupine under additive design intercropping system in Adet and Debre Tabor and areas with similar agroecology as it recorded the highest net return with acceptable marginal rate of return.

The utilization of nanoparticle in ethanol-diesel emulsions combustion catalyst is important. For this study, ethanol and diesel fuels are emulsified varying the ethanol amount as 5, 10, and 15% volume ratio designated as E5, E10, and E15, respectively, by using span 80 and tween 80 emulsifying agents. Nickel Zinc Iron Oxide (NiZnFe2O4) nanoparticle is used in each fuel sample with a dose rate of 25, 50, and 100 ppm. Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant is used to keep the nanoparticle homogeneously suspended in the fuel. Mechanical steering and ultrasonic vibrator are used to prepare the sample fuel. A single-cylinder diesel engine testing rig is used to test the performance. For the ethanol-diesel emulsion, the power and torque output decreased as the ethanol percentage and the BSFC increased. The nanoparticle addition improved power and torque output and reduced BSFC. Ethanol-diesel emulsion fuel performance characteristics could be improved with the utilization of NiZnFe2O4.

The main objective of this work is to analyse the impact of different EGR configurations (no EGR, cold EGR, and hot EGR) on exhaust emissions of PCCI-DI engine. Methanol port injection, dieseline direct injection, advanced injection timing, and different EGR rates were adapted and optimized on the baseline engine. A hybrid algorithm of grey relational analysis with the Taguchi method was implemented for optimization. Results were compared among the PCCI-DI combustion strategy with the baseline using cold EGR, hot EGR, and no EGR configurations. Both cold and hot EGR configurations resulted in lower emission of NOx plus smoke at different loads. At low loads, hot EGR showed promising results of lower HC and CO than the cold EGR with a difference of 18.33% and 33.3%, respectively. NOx and smoke reductions simultaneously and better trade-offs were obtained using cold EGR configuration.

Agronomic strategies such as choosing the optimal row ratio and planting legume crops at the right time are crucial for enhancing crop productivity. A field experiment was conducted in 2016 and 2017 to assess the influence of plant density and lupine intercropping time on tef field productivity. The treatments were as follows: tef was planted at a 20 cm inter-row spacing, lupine was sown at 20 and 40 cm inter-row spacing (row ratio of 1 tef: 1 lupine and 2 tef: 1 lupine) and lupine intercropped three times (1, 2, and 3 weeks after tef planting). Randomized complete block design (RCBD) with 3 replications were used. Two sole tef and lupine were planted. The results revealed 40 cm inter-row spacing and delayed lupine intercropping (3 weeks after tef planting) provided the maximum tef grain yield of 1.80 t ha−1. The sole cropping of lupine produced the highest lupine grain yield (2.63 t ha−1). Lupine intercropping at 40 cm inter-row spacing and two weeks after tef planting resulted in the highest land equivalent ratio (1.54), tef equivalent yield (2.45 t ha−1), area time equivalent ratio (1.11), system productivity index (2.5), monetary advantage index (15206 birr ha−1), net benefit (65109 birr ha−1), and marginal rate of return (602%). Therefore, farmers in the northwest Ethiopian highlands should consider intercropping lupine two weeks after tef planting in-between two rows of tef as an effective intercropping system.

Tef grain color is considered as the dominant parameter in the trading and price setting on the local markets. However, there are no comprehensive studies conducted so far on the preference and perception of actors on tef grain quality attributes and factors affecting it. Its implicitly assumed that other quality parameters also play a role in the value chain of tef. Using semi-structured questionnaires, this study researched the parameters and factors affecting the quality of tef, perceived by farmers, traders, and consumers in central and northwestern highlands of Ethiopia. Results from this survey indicated that grain color, size, density, shininess, cleanness, purity, and hulledness were the perceived tef grain quality attributes by all respondent groups'. Grain color followed by grain size, cleanness, and purity were the most perceived and directly or indirectly affected the price setting of tef. Farmer and trader respondents' perception for tef color was mainly dependent on their clients' (consumers). However farmer preferred the brown color tef for their consumption. Trader respondents categorized their client's preference of grain color on the income level as high, medium and low-income consumers. The high-income consumers mostly preferred the whitish color; middle-income for the mixed and brown color; and low-income for the brown color tef. The perception between farmer and trader, farmer and consumer, and trader and consumer as well as the same group of respondents living in different areas showed significantly (p < 0.05 to p < 0.0001) different on most of grain quality attributes. Nevertheless, there was no preference variability on grain color and density between farmer and trader respondents. While there were considerable differences in the color of tef between farmer and consumer and trader and consumer respondents. However, between the central and northwestern highland farmers (grain color, density and cleanness, traders, (color and cleanness), and consumer (color, density, purity, and hulledness) did not show considerable differences. From respondents, 100% of farmers, 97.7% of traders, and 93.3% of consumers perceived that grain quality variability comes from the variability of production area. Soil types, topography, and climatic factors were the main perceived causes for the variability of quality. Ninety eight percent of farmer and 100% of trader respondents perceived that black and brown color soils produced tef had highest quality in terms of whiteness or brightness as compared to tef produced on red soils. All respondent groups were also perceived that the quality of injera affected by tef grain quality. To better connect the value chain actors to the needs and preferences of tef grain and the economy in Ethiopia; the quality attributes like grain size, density, and shininess which affect the price of tef needs consideration in Ethiopian tef breeding program. The effects of soil type, agroecology, and crop variety should also be tested experimentally for a better understanding of factors influencing tef grain physical quality.

Striga hermonthica is a major biotic threat to worldwide food security, especially in sub-Saharan Africa. Sorghum production in North Gondar is challenged by the parasitic weed causing low crop yields. One of the options widely practiced is intercropping with legumes and variation in sowing dates of the intercropped crop species. A field experiment was conducted at two locations; Metema and Sanja at Gondar Agricultural Research Centers in the 2017/18 cropping season. Three sowing dates of soybean (2 weeks and 1 week before sowing and at a sorghum plantation) to control Striga. The study laid in a randomized complete block design with three replications in a factorial combination, two sorghum varieties; improved (Berhan) and a local variety commonly grown in the area and soybean “Afgat” varieties were used. A highly significant difference between Striga count (SC) and dry matter, grain yield (GY), above-ground biomass, and thousand seed weight (TSW) were the main effects and their interactions. SC, GY, and TSW were significant at Metema and combined over locations, but only GY at Sanja. Highest grain yield, biomass, thousand seed weight and lowest Striga counts was obtained in resistant variety at 2 weeks soybean sown before sorghum and, highest Striga was recorded in susceptible variety where soybean was sown at the same date with sorghum. Economic analysis results showed the highest and lowest net returns of 32,048.50 and 8,660 ETB per hectare from 2 weeks before with resistant sorghum and the same date with susceptible sorghum, respectively. Therefore, in the study area, the “Berhan” variety at 2 weeks before sorghum sowing is recommended for profitable sorghum production and Striga management.

The productivity of soybean in Assosa Zone particularly in Assosa and Bambassi districts is very low due to poor soil fertility management practices that resulted in severe soil acidity and low N-fixing inoculants in the soil. Hence, this experiment was conducted during the main cropping season of 2019 and 2020 in Assosa and Bambassi districts to evaluate the effect of biofertilizers, organic fertilizers, inorganic NPSB fertilizers, and lime on nodulation, growth, and yield of soybean (Glycine max L. Merrill). Factorial combinations of two biofertilizer inoculants (without biofertilizer (B1) and SB12 plus MAR1495 biofertilizers at their recommended rates of 500 g·ha−1 (B2); two organic fertilizers: without fresh cattle manure (M1) and fresh cattle manure at 10 t·ha−1 (M2); two lime rates: without lime (L1) and lime at 5 t·ha−1 (L2); two inorganic NPSB fertilizers: NPSB at 9.5-23-3.5-0.05 (F1) and NPSB at 19-46-7-0.1 (F2) at their recommended rates for soybean) were laid out in a randomized complete block design with three replications. Effective nodules, leaf area index, and grain yield were collected and analyzed using SAS 9.1.3 software. Results of the experiment showed that effective nodules, leaf area index, grain yield, bulk density, pH, total nitrogen, available phosphorus, organic carbon, and cation exchange capacity were highly (P

Analysis of climate variability and trends frequently takes place at large scale. For agricultural applications, however, highly localized climate conditions can be critically important. This certainly applies to tropical highland regions, where dissected topography and convectively dominated precipitation processes can lead to strong variability in both mean climate conditions and year-to-year climate variability. This study examines recent climate variability and trends (1981–2016) on Choke Mountain, located in the western Ethiopian Highlands. Through analysis of precipitation and temperature records at monitored locations, we explore observed variability in climate patterns and trends across sites and seasons. The lens for our spatial analysis is the agroecosystem (AES), defined on the basis of prevailing climate and cropping systems, which currently serve as the foundation for climate adaptation planning in the region. We find that interannual temperature variability is greatest in the hottest, driest AES, and is most pronounced in the dry season. All AES warmed significantly in all seasons over the analysis period, but the magnitude of trend was greatest in high elevation AES. Precipitation variability was also large across AES, with largest interannual variability found in the dry season. This season is frequently excluded in climate analyses, but it is a critical harvest time and irrigation period. Trends in rainfall anomaly and precipitation concentration index are less clear, but there is a tendency towards drying and increasing irregularity of rainfall. Interestingly, we find little association between the El Niño Southern Oscillation (ENSO) and temperature or precipitation variability at our study sites. This suggests that even though ENSO is a widely recognized driver of large-scale rainfall variability in the region, its impacts are highly spatially variable. This has implications for applying ENSO-based precipitation outlooks to agricultural management decisions. Farmer interviews reveal that local perceptions of climate variability and trends are generally consistent with the objective observations.

Fruit and Vegetables are growing both rain fed and irrigation in Ethiopia and important for food security and income generation to a large proportion of the rural household. Enhancing onion farmers to reach markets and actively engage in the markets key challenges influencing onion production in Ethiopia. So the study aimed to analyze determinates of onion market supply. The study specifically aimed to address determinates that affecting onion production and market supply of rural households. A total of 275 households were selected using a multi-stage sampling technique followed by a probability proportional to sample size. The result indicated that in the study area 79.27% of onions producing households were male-headed whereas, the remaining 20.73% were female-headed household heads. On the other hand model results show that sex, age, household size, land size, motor pump, marketing contract, post-harvest value addition and market information positively and significantly affected the volume of onion supplied to the market. The findings imply that policymakers as well as policies designed at national level should consider on promoting the market contract, dissemination of improved onion varieties and input of production, intensification of land, expanding of post-harvest value addition activities and expanding the existence of irrigating equipments.

Potentials of pragmatic crop rotation practices and organic matter applications for restoration of soil health and productivity of degraded highland crop fields were studied for three rotation phases from 2013 to 2015 in northwest Ethiopia. Factorial combinations of five crop rotations (R1+ = bread wheat–clover–potato, R2+ = clover–bread wheat undersowing lupine–potato, R3+ = potato–clover–bread wheat, R4+ = bread wheat undersowing lupine–potato undersowing lupine–bread wheat, and R5+ = lupine–potato undersowing lupine–bread wheat) and four manure application rates [M1 = control/0tha−1 manure, M2 = 2.5 tha−1 sesbania green manure (SGM), M3 = 5 tha−1 fresh cattle manure (FCM), and M4 = 2.5 tha−1 SGM + 5 tha−1 FCM] were laid out in randomized complete block design (RCBD) with four replications. Plus sign (+) with crop rotation indicated that crop residues and green manure of legumes at 50% flowering were incorporated into the soil. The results showed that soil properties and productivity of crops were markedly improved with three-year interventions of crop rotation and manure application. As compared to that of the initial before starting the experiment, soil bulk density, pH, CEC, and contents of organic carbon, total nitrogen, available phosphorous, and exchangeable potassium were improved on average by about 23%, 18%, 67%, 89%, 150%, 89%, and 44%, respectively, with R1+M4 treatment combination in three-year period. Similarly, compared to that of 2013, productivity of bread wheat and potato increased on average by about 446% and 540% in 2015 with R3M4 and R1M4, respectively.

The study was initiated to explore genetic advance and rate of genetic progress over years of bread wheat genotypes in Ethiopia. Twelve bread wheat genotypes released in between 1995 and 2012 were used as experimental treatments. The experimental treatments were laid out on randomized complete block design with three replications across locations over 2 years. The study was conducted at Adet, Debretabor, Finoteselam, Injibara and Simada in 2014 and 2015 cropping seasons. The combined analysis of variance of genotypes, environments and their interactions showed significant difference (P

Onion is an important vegetable product for food security and income generation to a large proportion of the rural household of Ethiopia. Enhancing onion farmers to reach markets and actively engage in the markets as a key challenges influencing onion production in Ethiopia. The perishability nature of onion necessitates an effective marketing channel choice decision. So the objective of this study was the analysis of factors affecting market outlet choice decision of farmers. Multi-stage sampling procedure was used to select the sample kebeles and households, whereby 275 farm household using a stratified random sampling method for this study. Both primary and secondary data were collected to address the objectives. The collected data were analyzed using descriptive statistics and an econometric model by using SPPS and STATA software. Multivariate probit model was used to analyze factors affecting market outlet choices of smallholder onion producers. Multivariate probit model result showed that the probability of choose wholesales, retailer, rural collectors, and consumers market outlet was significantly affected by post-harvest value addition, amount of onion production, land size allocated for onion production, ownership of motor pump, educational status of the household head and the total livestock owned. Based on the finding the government and the concerned stakeholders should focus on promoting the dissemination of improved onion varieties and input of production, intensification of land for onion, expanding of post-harvest value addition activities, strengthening of the existence of formal and informal education and promote and encourage onion farmers on investment onion production.

Teff is the most strategic cereal crop grown from high rainfall to drought prone areas of Ethiopia, where it covers nearly 30% of the land allotted for cereals. However, its productivity remains very low due to lack of knowledge and research interventions. To investigate the grain yield potential, estimate the genetic parameters, and the diversity, a pot experiment with intensive management and a field experiment with conventional management at two contrasting locations for two seasons using the same 317 genotypes and additional 3 improved cultivars in the field experiment were carried out. The results showed highly significant variation among the genotypes for grain yield, biomass, harvest index, and phenological traits under both experiments. The best linear unbiased predictor (BLUP)-adjusted grain yield performance of the genotypes ranged from 4.2 to 8.8 g/plant in the intensive management and 1.8 to 4.3 g/plant in the field growing condition with conventional management. Coefficient of genetic variation, heritability, and expected genetic advance for grain yield were the highest in both experiments. Among the phenological traits, the grain filling period in the intensive growing condition exceptionally showed the highest genetic coefficient of variation and genetic advance. The high grain yield performance and wider range of the harvest index observed under the intensive management condition with moderate to high heritability signifies the genetic potential of teff for further improvement through trait recombination.

Susceptibility to lodging is a major constraint on teff production in Ethiopia, but efforts to develop lodging-resistant cultivars have not been successful. We studied the mechanical properties of teff culms and associated agro-morphological traits in field experiments with 320 teff accessions at two sites in northwestern Ethiopia during the 2018 and 2019 growing seasons. The results showed significant variability in both mechanical properties and agro-morphological traits among accessions. Traits contributing to lodging resistance, such as internode diameter, pushing resistance, and base failure moment, were significantly positively correlated with each other and with plant height. Similarly, the correlation of those traits with lodging index was significant and positive. In contrast, tiller number showed a significant negative correlation with lodging index. The peduncle–panicle length, which generally accounted for 59% of the plant height, should be a target when breeding for semi-dwarfism. Root system development, which reached a depth of more than 1 m in tall and 57 cm in dwarf teff accessions, signifies the presence of genetic variabilities for future root lodging studies in teff, and it may also explain why teff performs well in drought-prone areas of Ethiopia. Breeding programs for lodging resistance might focus on accessions with good standing ability (high base failure moment) and introgression of stem strength with a semi-dwarf phenotype. Alternatively, selection for a large internode diameter, increased pushing resistance and base failure moment, and a reduced tiller number should be considered.

A field experiment was conducted for 2 years during the main cropping seasons of 2017 and 2018 in Fogera Plain to study the productivity response of lowland rice varieties to different sources of nitrogen fertilizer. The experiment was conducted using a factorial arrangement of three sources of N fertilizer (conventional urea, slow-release urea and urea supergranule) and three varieties of rain-fed lowland rice (Hiber, Ediget and X-jigna) laid out in a randomized complete block design (RCBD) with three replications. The recommended rate of 69 kg N ha–1 was used for all three sources of nitrogen fertilizer. Results showed that highest soil-plant analysis development value, leaf area index (LAI), thousand-grain weight, biomass and grain yields of rice were recorded with the interaction of urea supergranule N fertilizer application and Hiber rice variety, while the lowest values of the parameters were recorded with the interaction of conventional urea application and X-jigna rice variety. Rain-fed lowland rice grain yield of 4.6 ton ha–1 was obtained from the interaction of urea supergranule and Hiber rice variety. Economic evaluation results showed also that the highest net return of 58,947.50 Ethiopian Birr ha–1 was estimated from the combination of urea supergranule and Hiber rice variety. According to the present results, the interactions of urea supergranule N fertilizer with Hiber and Ediget rice varieties were found as the first and the second outsmarted combinations that would be used further for exploiting more grain yield and net benefits of rain-fed lowland rice without yield penalty in Fogera Plain, northwest Ethiopia.

Vegetables are important for income generation to a large proportion of the rural households. Enhancing tomato farmers to reach markets and actively engage in the markets is a key challenge influencing tomato production in Ethiopia. The perishable nature of tomato necessitates effective marketing channels choice decisions. So, the main objective of this study was analyzing the determinants of market outlet choice decisions of tomato producers. The two-stage random sampling procedure was used to select the sampled kebeles and households, whereby 235 farm households were surveyed for the study. Both primary and secondary data were collected to address the objectives. The collected data were analyzed using descriptive statistics and an econometric model by using SPSS and STATA software. Multivariate probit Model results showed that the probability to choose wholesalers, collectors, retailers, and consumers market outlets were significantly affected by age of the household head, educational status of the household head, distance to the nearest market, access to credit, owning transport facility, land allocated to tomato and household size. Policy implications drawn from the study findings include that the government and concerned stakeholders should focus on strengthening rural-urban infrastructure, intensification of land for tomato, expanding the accessibility of credit and strengthening the existence of formal and informal education.

Sustainable intensification of agriculture is a means of reducing the demand for increased land resources. A field experiment was conducted at two major finer millet producing areas of northwestern Ethiopia from 2017 to 2018 cropping seasons with the objective of assessing land use efficiency, profitability, and productivity of finger milt in finger millet-legume additive design intercropping. Factorial combinations of two legume crops (haricot bean and lupine) intercropped with finger millet, two planting methods (row and mixed) and three finger millet-legume planting ratios (100%:75%, 100%:50% and 100%:25% of the recommended seed rate of sole crops) were laid out in a randomized complete block design with three replications. Two sole crop finger millets (planted in rows and broadcast) and two sole crop legumes (haricot bean and lupine) were included for comparison purposes. Results revealed that the primary objective of maintaining the “full” grain yield of finger millet in an intercropping was achieved in finger millet-haricot bean row intercropping at 100:25 (2.68 tone ha-1) and100:50 (2.72 tone ha-1) planting ratios. Average over the three scenarios, the latter cropping system (65%) and finger millet haricot bean intercropping at 100:75 planting ratio (56%) gave significantly higher yield advantage over sole cropping of finger millet and haricot bean separately. Maximum marginal rate of return was observed in finger millet-lupine mixed intercropping (1281%) and finger millet-haricot bean row intercropping (1175%). Thus, it could be concluded that the latter cropping system could be used for improving household food security to smallholder farmers by increasing the productivity of finger millet, land use efficiency, and profitability.

Teff is the only cultivated cereal crop from the genus Eragrostis and it is the major staple food of Ethiopians. In Ethiopia, the quality of teff and its market price are primarily determined by its grain color. The objective of this study was to evaluate the effects of soil physicochemical characteristics across multiple locations in the two main teff growing regions of Amhara and Oromia states in Ethiopia on teff grain color and nutritional quality of a single variety. Grain and soil samples were collected from 24 field sites cultivated with the popular teff variety ‘Quncho’ (DZ-Cr-387/RIL-355). The teff grain samples collected from the 24 locations were evaluated for grain color, proximate composition, amino acid composition, and grain mineral concentration and the soil samples were analyzed for their physicochemical properties. Sample location means were considered different p < 0.05. Teff grain color indices of hue (H), saturation (S), and brightness (V), grain proximate composition, amino acid composition, and mineral concentration differed among locations (p < 0.05). There were significant negative correlations between grain S color value and soil pH, SOC, Ca, Mg, S, and Na. Soils with greater pH, SOC, Ca, Mg, and S generally had lower S values and thus, whiter color teff grains. There were considerable variations in the measured parameters for soil and teff grain physicochemical properties. The results indicated an opportunity for management interventions necessary to obtain uniformity in grain color and chemical composition for the same variety of teff grown in the two major regions in Ethiopia.

Bast fiber dyeing process is common practice as the value addition of most bast fibers demanded for various commercial and household applications. In this research work, kusha fiber (extracted previously) was subjected to dyeing using direct, reactive, vat and cationic dyes for the first time. Dyeing process was perfrmed using concentrations 0.5%, 1%, & 3% (W/W) dye to fiber with MLR 1:20. After dyeing process, performance of dyed fiber and tensile tests were conducted. The results revealed that K/S value of all dyed kusha fiber samples increases as the concentration of dyes applied increases. The dyed fibers color fastness to washing was found good both in dry and wet rubbing fastness. Reactive dyed samples have shown good rubbing fatness performance over the others. Regarding light fastness, the result shows there was good performance for all samples according to blue wool light fastness standard that exceeds 6. The tensile strength and elongation of dyed samples showed slight decrement both in vat and direct dyed samples; whereas, considerable decrement was observed both in reactive and basic dyed samples due to formation of covalent bond and acid processing medium.

In this paper, the space Fp of fuzzy prime ideals of Heyting almost distributive lattice H is studied, and it is shown that the collection of all sets Mη is a topology on Fp, where η is a fuzzy ideal on H and Mη=θ∈Fp|η⊈θ. The only compact subset of the space Fp is given. A fuzzy congruence relation Θ on H is defined, and the homomorphism between the set of all fuzzy ideals of H and the set of all fuzzy ideals of H/Θ is established. Furthermore, we established an isomorphism between fuzzy spectrum of H and fuzzy spectrum of H/Θ.

Currently, eco-friendly products have been given great attention as the world is being polluted severely by non-biodegradable products and by-products. Different textile products have their own share in affecting the environment. This research is focused on exploring alternative bast fiber products to support the supply chain and to assess the possibility of using this fiber as a substitute to already available bast fibers. Kusha fiber was extracted and optimized from Ethiopian kusha plant stem – Girardinia bullosa (Steudel) wedd. – using caustic soda solution by varying the concentration, temperature, and time using design expert 6.0.10, quadratic model software. Tensile property, chemical composition, X-ray diffractometer (XRD), Fourier-transform-infrared spectroscopy (FTIR), fiber morphology, and thermogravimetric analysis (TGA) of the fiber were determined. Fiber characterization showed its tensile strength, and the cellulose content was equivalent to or even better than other bast fibers. Morphology of the fiber was similar to that of typical cotton with visible lumen and a slightly flat surface. Therefore, this new extracted fiber has a great potential to be used for different applications such as fiber-reinforced composites, textile furnishing, apparel, and nanocellulose extraction.

In this study, fuzzy ideals in pseudo-hoop algebras are presented. Also, we investigate fuzzy congruences relations on pseudo-hoop algebras induced by fuzzy ideals. By using fuzzy ideals, we create the fuzzy quotient pseudo-hoop algebras and identify and demonstrate the one-to-one relationship between the set of all normal fuzzy ideals of a pseudo-hoop algebra H with conditions p DN and the set of all fuzzy congruences relation on H. Additionally, we investigate the relationship between fuzzy ideals and fuzzy filters in pseudo-hoop algebras by considering the set of complement elements of pseudo-hoop algebras. Lastly, we study fuzzy prime ideals and fuzzy ⊙-prime ideals and their relation.

In this paper, the concept of belligerent fuzzy GE-filter of GE-algebra is introduced. The relationship between a fuzzy GE-filter of GE-algebra and a belligerent fuzzy GE-filter of GE-algebra is given. Further, it is shown that a finite product (union) of belligerent fuzzy GE-filters of GE-algebras is a belligerent fuzzy GE-filter of the finite product (union) of GE-algebras.

In this paper, we study L-congruences and their kernel in a subclass Kn,0 of the variety of Ockham algebras A. We prove that the class of kernel L-ideals of an Ockham algebra forms a complete Heyting algebra. Moreover, for a given kernel L-ideal ξ on A, we obtain the least and the largest L-congruences on A having ξ as its kernel.

In this paper, we study fuzzy congruence relations and kernel fuzzy ideals of an Ockham algebra A,f, whose truth values are in a complete lattice satisfying the infinite meet distributive law. Some equivalent conditions are derived for a fuzzy ideal of an Ockham algebra A to become a fuzzy kernel ideal. We also obtain the smallest (respectively, the largest) fuzzy congruence on A having a given fuzzy ideal as its kernel.

In this paper, we introduce the concept of relative fuzzy annihilator ideals in C-algebras and investigate some its properties. We characterize relative fuzzy annihilators in terms of fuzzy points. It is proved that the class of fuzzy ideals of C-algebras forms Heything algebra. We observe that the class of all fuzzy annihilator ideals can be made as a complete Boolean algebra. Moreover, we study the concept of fuzzy annihilator preserving homomorphism. We provide a sufficient condition for a homomorphism to be a fuzzy annihilator preserving.