Evaluation of crop residue retention, compost and inorganic fertilizer application on barley productivity and soil chemical properties in the central Ethiopian Highlands

Soil fertility depletion is a serious problem in the highlands of Ethiopia. A field experiment was conducted for two consecutive cropping seasons (2009-2010) on farmers’ fields in Degem Wereda, North Shewa, Oromiya Regional State. The objective of this study was to evaluate the effects of crop residue, compost, inorganic fertilizer and cropping system as a component of an integrated soil fertility and plant nutrient management system on barley productivity and soil chemical properties. The treatments included eight selected combinations of organic and inorganic nutrient sources, including retention of crop residues. The design was randomized complete block with three replications. Results showed that barley yield and some yield components significantly responded to the application of different soil fertility management practices. The highest barley grain yield (2575 kg/ha) and total biomass (5185 kg/ha) were obtained from the applications of the recommended nitrogen and phosphorus (NP) fertilizer followed by 2353 and 5148 kg/ha for grain yield and total biomass, respectively, due to the applications of half doses of the recommended NP fertilizer and 3 t/ha EM-compost. The grain yield of barley consistently increased as the total biomass increased. Although the highest yields were achieved from the application of the recommended NP fertilizer rate, the other integrated soil fertility management treatments also resulted in significant yield advantages compared to the control. Yields from the applications of three treatments 1/ half the recommended rate of NP fertilizer and 3 t/ha conventional compost; 2/ retention of 30% of crop residue plus half the recommended rate of NP fertilizer and faba bean mixed intercropping; and 3/ half doses of NP fertilizer plus 3 t/ha EM-compost were almost identical. Barley grain yield showed significantly positive correlations with the total biomass (r = 0.94), spike length (r = 0.43) and number of productive tillers (r = 0.42), respectively. Partitioning of treatments into single degrees of freedom orthogonal contrasts revealed that barley grain yield, total biomass, spike length and productive tillers significantly differed due to the different soil fertility management treatments. From the results of this study, it can be concluded that application of half the recommended rate of NP fertilizer with 50% of the recommended dose of compost (3 t/ha) can be an alternative best integrated soil fertility management measure instead of only inorganic fertilizers for sustainability. The results of this experiment can be reproducible in other similar agro-ecologies and farming systems of the country.Keywords: Barley productivity, chemical soil properties, compost, crop residue, inorganic fertilizer, sustainabilit

An investigation on the status of resilience among blind adolescent students

Ethiopia has one of the world’s highest rates of visual disability. Among persons with visual disability living in Bahir Dar town, adolescents take a significant share of this population. Living sightless for anyone, whether young or old, educated or uneducated, rich or poor, with adequate support or without it is seriously challenging. The quality of life of blind persons is significantly influenced by the resilience they possess. The status of resilience of blind adolescents learning in schools of Bahir Dar town is not known. Against this backdrop, this study was germinated and designed to explore the level of resilience of blind adolescents. A survey design was employed to examine the resilience status of blind adolescent students and the influence of some demographics on resilience. Data were collected from a random sample of 60 blind adolescents using Connor-Davidson Resilience Scale. Descriptive statistics, t-test, one-way ANOVA followed by Scheffe post hoc comparisons were used to analyze the data. The results revealed lower level of resilience. Gender, time of onset of blindness, parental education and family income were influencing resilience. Implications for education and rehabilitation of blind adolescents are explored

‘Why should I worry, since I have healthy feet?’ A qualitative study exploring barriers to use of footwear among rural community members in northern Ethiopia

Objective To explore the influence of personal, cultural and socioeconomic factors related to footwear use and non-use in northern Ethiopia. Design A qualitative study was conducted using focus group discussions and in-depth individual interviews. Data were collected using semistructured interview guides. Setting The study was conducted in East and West Gojjam Zones, Amhara region, northwest Ethiopia. Participants A total of 91 individuals from 4 target groups participated in individual and group interviews: (1) non-affected community leaders including Idir (a form of social insurance) leaders, school principals, kebele (the lowest administrative unit) officials, health professionals, teachers, merchants and religious leaders; (2) affected men and women; (3) non-affected men and women not in leadership positions; and (4) school children (both male and female). Results Participants perceived a range of health benefits from donning footwear, including protection against injury and cold. Various types of shoes are available within the community, and their use varied depending on the nature of activities and the season. Personal and socioeconomic barriers hindered the desire to consistently use footwear. Widely established barefoot traditions and beliefs that footwear is uncomfortable, heavy and may weaken the feet have made the regular use of footwear uncommon. Economic constraints were also mentioned as hindering ownership and use of footwear. Distance from places where shoes could be bought also contributed to limited access. Cultural influences promoting gender inequality resulted in women being least able to access shoes. Conclusions We identified several individual, cultural and socioeconomic barriers that influence individuals’ decisions about and use of footwear in rural northern Ethiopia. Promoting education on the health benefits of footwear, curbing podoconiosis-related misconceptions and integrating these with economic empowerment programmes, may all improve the use of footwear

Oil Production from Yarrowia lipolytica Po1g Using Rice Bran Hydrolysate

The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1–4% v/v), reaction times (1–8 h), and reaction temperatures (60–120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively

Current pretreatment technologies for the development of cellulosic ethanol and biorefineries

Lignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin–carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids)

Examining advance time of furrow irrigation at Koga irrigation scheme, Ethiopia

Koga irrigation scheme was developed to irrigate about 7004 ha. Furrow irrigation is the recommended method for the distribution of water. However, furrow irrigation has inherent inefficiencies due to deep percolation on the upper end and runoff at the lower end of the furrow. These losses depend on furrow length, furrow gradient, surface roughness, stream size and cutoff time. These factors play significant role to influence the advance time of irrigation and the operation rule of the scheme. This paper examines the advance time of furrow irrigation at Koga. The experiment was conducted during 2012 irrigation season in two periods (February and April). The advance time of irrigation was monitored at three discharge rates and four furrow gradients at 90–110 m furrow length. The required discharge was measured using RBC flume. The average advance time at respective discharge rates of 0.3, 0.6 and 0.8 litre/sec range from 290–460 min, 150–437 min and 100–294 min during 1st irrigation; and 115–370 min, 78–189 min and 43–217 min during 2nd irrigation. The advance time vary greatly among the discharge rates when the furrow length increases. The advance time of water at 0.5, 1.0, 2.0 and 2.5 % gradients was 236, 181, 197 and 398 min at 1st irrigation and 163, 175, 220 and 88 min at 2nd irrigation respectively. Furrow gradients and surface irregularities result in great variation of advance time. The advance time becomes shorter when the field gets smoother during 2nd irrigation. Under non-levelled and irregular field conditions, 0.6–0.8 litre/sec application rate can be suggested to irrigate 30–40 m furrow lengths in order to improve application efficiency above 60% and to optimize the daily operation rule of the overall scheme. The result of this study indicates the relevance of examining the furrow length, discharge and application time recommended in the feasibility study of irrigation schemes