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In Ethiopia five Eucalyptus species were adopt wide area and Eucalyptus camaldulensisi more dominant in low land and middle land area and economically very important. This leads to farmers converted portion of their farmland to Eucalyptus camaldulensis woodlots. The aim of this study was to assess the impact of E. camaldulensis woodlot on the soil properties and teff (Erogrsticteff) yields on an adjacent cropland. A plot of 2m x 1.5m area was laid down inside plantation (assumed zero m), at one, three, six, nine and20 m distances away from the E. camaldulensis woodlot in to the adjacent cropland. This was replicated on three farmlands. Teff was grown on the plots and the yield, height, and biomass of teff were measured and thirty six soil samples were collected from experimental field. The soil bulk density (p

A study was conducted in South Omo Zone, Ethiopia with the aim of assessing the population status of the frankincense tree Boswellia neglecta and investigating its resin essential oil chemical comp...

Ziziphus spina-christi is a multipurpose tree which grows naturally on the farm lands in Habru district. Since, the effects of this tree on soil and crop have not scientifically quantified; this study has been carried out with the aim of assessing the effect of Ziziphus spina-christi on soil physicochemical properties, grain and biomass yield of sorghum.Five isolated and nearly identical Ziziphus spina-christi tree growing on farm lands with similar site condition were selected and canopy coverage of each tree was divided into four radial transects. Soil samples from three horizontal distances: 1.2m, 2.9m and 15m with two soil depths (0–15cm and 15-30cm) were taken for analysis of soil physico- chemical properties. Three quadrates 1m x1m at each transect and distances were laid for sorghum grain yield and biomass estimation. The result shows that soil pH, EC, CEC and soil texture were not significantly (p>0.05) influenced by Ziziphus spina-christi tree, whereas soil bulk density, soil moisture content, total nitrogen, organic carbon, available phosphorus and exchangeable cation (Mg, Ca and K) were significantly (P0.05).Hence, retaining of this tree on crop land improves the soil fertility status.

The effect of Acacia seyal tree on soil bulk density, soil moisture content, grain and biomass yield of tef (Eragrostis tef) were examined on six selected comparable A. seyal trees on croplands. Composite soil samples (6 trees × 3 distances × 2 soil depths) were collected at three distances from the tree base (1, 2.5 and 9 m) and two soil depths (0-15 and 15-30 cm) in four radial directions. Grain and biomass yield of tef were also sampled from 1 m2 plot at the three distances from where the soils were sampled. The result indicated that soil bulk density (BD) and soil moisture content (SMC) were significantly affected both by distance from the tree base and soil depths. Grain yield of tef and SMC was higher whereas BD was lower under the canopy of A. seyal than that of beyond the canopy. The reduction of grain and biomass yield at the nearest distance may be attributed by competition for light and water between tree and crop. However, biomass yield of associated tef were the same under the canopy and away from the canopy of A. seyal. Therefore, the result indicates that retaining of A. seyal tree on croplands with the integration of food crops, could be an additional benefit for the farmers without competing their crop production. Key words: Acacia seyal, soil physical property, biomass, grain yield of tef.

Conservation agriculture is claimed to be one of the solutions for the problems of poor agricultural productivity in sub-Saharan countries. The impact of conservation agriculture depends on environmental factors such as slope, vegetation, soil type, rain fall pattern and intended crops. This study was conducted from 2013 to 2014 with the objective of assessing the impact of conservation agriculture practices on soil chemical properties. Five main treatments were selected for the study: Monocropping (maize) without crop residue, Monocropping (maize) with crop residue, Crop rotation (maize and haricot bean) with crop residue, Intercropping (Haricot bean with maize) with crop residue and a grazing land as a control. A Randomized complete block design with four replications was used. A total of 40 composite soil samples (4 replication * 5 treatments * 2 soil depth) were collected and analysed for selected soil chemical properties. Results showed that soils in the study area were moderately acidic, and contained medium level of available phosphorus (AP) (7.33±0.58 mg/kg), but low concentration of total N (0.176±0.02%). Soil pH, soil organic carbon (SOC), total nitrogen (TN), C/N, and AP did not significantly differ (p=0.958, p=0.998, p=0.219, p=0.140 and 0.568) respectively, among the treatments following the four year of conservation agricutural practices. Thus, conservation agriculture has little effect on soil properties in short term, but it may take longer time to influence on different soil chemical properties in the study area.

This review was made to bring forth the contradicting outlooks from different research findings, challenges on the Eucalyptus species and show the opportunities we have with the tree. Due to the impact of Eucalyptus tree species on ecological health and agricultural productivity, ecologists, policy makers and politicians have had a negative view on this tree species. Hence, attempts are made to remove the tree from the agricultural landscape in some part of Ethiopia. In contrast, the farmers of Ethiopia prefer the fast growing, economically attractive, and the quality wood yields of Eucalyptus tree species. So we need to look for other dimension to coincide the existing contradictions. Eradication of the tree cannot be solution without replacing with suitable tree species for maintaining biodiversity and ecological balance. The tree can continue to supply fuel wood and construction material and thereby retard the rate of deforestation and loss of biodiversity resources of the remnant forests of the country. Collaborative work is crucial to gear efforts towards the establishment of a proper management system for the cultivation of Eucalyptus tree. Appropriate management practices such as species selection, planting site selection, correct site-species matching and efficient utilization can maximize the opportunity obtained from the tree. It is also very important to look for alternative trees species to replace Eucalyptus trees, and further studies are required to test the level of Eucalyptus species impact on specific ecosystem. Also, polices need to achieve a reasonable trade-off between the socio-economic value and agro-ecological conservation. Key words: Agro biodiversity, biodiversity, ecology, eucalyptus, forest.

The establishment of grazing exclosures is widely practiced to restore degraded agricultural lands and forests. Here, we evaluated the potential of grazing exclosures to contribute to the “4 per 1000” initiative by analyzing the changes in soil organic carbon (SOC) stocks and sequestration (SCS) rates after their establishment on degraded communal grazing lands in Tigray region of Ethiopia. We selected grazing areas that were excluded from grazing for 5 to 24 years across the three agroecological zones of the region and used adjacent open grazing lands (OGLs) as control. Soil samples were collected from two depths (0–15 cm and 15–30 cm) and SOC and aboveground C stocks were quantified in both exclosures and OGLs. The mean SOC stock and SCS rate in exclosures (0–30 cm) were 31 Mg C ha−1 and 3 Mg C ha−1 year−1, which were respectively 166% and 12% higher than that in the OGLs, indicating a positive restoration effect of exclosures on SOC storage. With increasing exclosure age, SOC stock and SCS rate increased in the exclosures but decreased in the OGLs. Higher SOC stock and SCS rate were recorded in 0–15 cm than in 15–30 cm. The relative (i.e., to the SOC stock in OGLs) rates of increase in SOC stocks (70–189‰ year−1) were higher than the 4‰ year−1 and were initially high due to low initial SOC stock but declined over time after a maximum value of SOC stock is reached. Factors such as aboveground biomass, altitude, clay content and precipitation promoted SOC storage in exclosures. Our study highlights the high potential of exclosures for restoring SOC in the 0–30 cm soil depth at a rate greater than the 4‰ value. We argue that practices such as grazing exclosure can be promoted to achieve the climate change mitigation target of the “4‰” initiative.

Background: Soil fertility decline in agricultural land is due to intensive cropping system, shortening of the fallow period, reduced manure application, extensive use of crop residues as fuelor fodder and removal of ground cover. This study investigated the effect of biochar (BC), lime and farmyard manure (FYM) on growth, yield and grain nutrient of wheat on two cropland sites in southern Ethiopia. Result: The effect of site was significant (P < 0.05) for most parameters investigated, indicating the influence of soil type. The effects of BC, lime, and FYM were significant (p ≤ 0.001) on straw yield, grain yield, and total biomass. However, BC (5 tha -1 ) produced the highest straw yield, grain yield, and total biomass. Similarly, BC and lime significantly (P < 0.001) affected plant height, and tiller numbers and productivity. BC (5 tha -1 ) gave the highest plant height, total tillers, and productive tillers, maximum number of seeds per spike, while FYM (10 tha -1 ) produced the highest spike length. Biochar significantly (P < 0.05) increased the concentrations of P and K in wheat grain. The highest effect on grain Ca concentration was from the application of lime while the highest on grain N concentration was from FYM (10 tha -1 ). Conclusion: The effect from BC was attributed to improvements in soil pH, CEC, nutrient availability and water retention. Thus BC has a good potential as a soil amendment for smallholder farm crop production.

Background: Soil fertility decline in agricultural land is due to intensive cropping system, shortening of the fallow period, reduced manure application, extensive use of crop residues as fuel or fodder and removal of ground cover. This study investigated the effect of biochar (BC), lime and farmyard manure (FYM) on growth, yield and grain nutrient of wheat on croplands at two sites in the southern Ethiopia.Result: Site significantly (P

Improved cook stoves (ICS) have perceived to exert a significant impact on households' economy, human health, and global climate change. There are few studies on ICS emissions and fuel use performance and on the factors that affect their adoption in Ethiopia. Thus, the objectives of this study were assessing: (a) the emissions of CO, CO2 and fine particulate matter (PM2.5) of improved Merchaye and Lakech charcoal stoves in comparison with traditional metal stoves; (b) specific fuel consumption (SFC) of the two ICS; and (c) the factors that affect their adoption. Data were collected using the Water Boiling Test in a laboratory and household survey. The results showed the Merchaye stove reduced emission of CO, CO2 and PM2.5 by 28, 22 and 27% respectively in comparison to a traditional charcoal stove. Whereas, the Lakech stove reduced emission of CO, CO2 and PM2.5 by 15, 8 and 13%, respectively. In non-sustainable fuel wood harvest circumstances, the annual emission reduction potential for individual Merchaye stoves was 0.33 t CO2e and Lakech stoves 0.14 t CO2e yrâ1. The SFC of Merchaye and Lakech were reduced by 222 and 164 g dâ1, respectively. The two ICS also reduced the time required for cooking. Regarding the status of adoption of ICS, 43.7% the sample households were adopters of Merchaye stoves and 31.3% Lakech, stoves. Whereas the non-adopters comprise 25% of the sample. Adoption of ICS was influenced by household head age, sex, education level and income. The results may have implication for mitigation of climate change, forest degradation and household workload. Keywords: Merchaye, Lakech, Emission, Adoption, Climate change

Considering the importance of soil organic carbon (SOC) and the scarcity of data on how soil management influences its storage in the region, this study assessed the long-term impact of different soil management systems on SOC in southern Ethiopia using the DAYCENT model. The conservation management systems considered were minimum tillage, crop residue (CR) retention, fertilization and their combinations. We parameterized the model with data from studies in the literature. We then modeled conventional cropping system for smallholding farms over a 30-year period (1991–2020) as the business as usual scenario (BAU). Then we assessed the impact of alternative conservation management scenarios compared with the BAU scenario. Our results indicated that the conservation management scenarios increased SOC at 0–20 cm depth in the range 0.34–9.71 Mg C ha−1 over 30 years when compared to BAU practices. The individual effect of fertilization, CR retention or minimum tillage management practices on SOC stock were lower than the response of the combined conservation management practices. The combined 50%–75% CR retention, no-tillage (NT), and 32 kg N ha−1 fertilization provided the highest SOC sequestration. These combinations, increased SOC in the range 8.10–9.71 Mg C ha−1 over 30 years equivalent to rates of 0.27–0.32 Mg C ha−1 yr−1. While long-term empirical data from field experiments are lacking, model results suggest that the combined 50–75% CR retention, NT, and increased N fertilization have a potential to increase SOC sequestration in resource-limited smallholding croplands. The results may be useful for researchers, policy maker and other stakeholders.

Grazing exclosures have been promoted as an effective and low-cost land management strategy to recover vegetation and associated functions in degraded landscapes in the tropics. While grazing exclosures can be important reservoirs of biodiversity and carbon, their potential in playing a dual role of conservation of biodiversity and mitigation of climate change effects is not yet established. To address this gap, we assessed the effect of diversity on aboveground carbon (AGC) and the relative importance of the driving biotic (functional diversity, functional composition and structural diversity) and abiotic (climate, topography and soil) mechanisms. We used a dataset from 133 inventory plots across three altitudinal zones, i.e., highland, midland and lowland, in northern Ethiopia, which allowed local- (within altitudinal zone) and broad- (across altitudinal zones) environmental scale analysis of diversity-AGC relationships. We found that species richness-AGC relationship shifted from neutral in highlands to positive in mid- and lowlands as well as across the altitudinal zones. Structural diversity was consistently the strongest mediator of the positive effects of species richness on AGC within and across altitudinal zones, whereas functional composition linked species richness to AGC at the broad environmental scale only. Abiotic factors had direct and indirect effects via biotic factors on AGC, but their relative importance varied with altitudinal zones. Our results indicate that the effect of species diversity on AGC was altitude-dependent and operated more strongly through structural diversity (representing niche complementarity effect) than functional composition (representing selection effect). Our study suggests that maintaining high structural diversity and managing functionally important species while promoting favourable climatic and soil conditions can enhance carbon storage in grazing exclosures.

In developing countries, fuelwood extraction is one of the main drivers of deforestation, forest degradation, and greenhouse gas (GHG) emissions. This study aimed to investigate the use, management, and attitudes towards biogas technology in rural communities in Ethiopia and assess its’ potential in reducing the consumption of biomass fuels and emissions of GHG. A questionnaire survey sampled from 40 biogas user and 40 non-user households was used to collect data. The biogas flow rate was measured using a gas flow meter from three random biogas digesters. Biogas and non-biogas user households reported similar socioeconomic perspectives. Our results showed that 92.5% of biogas user households and 77.5% of non-users had a positive attitude towards biogas technology, however, 52.5% of the non-users lacked information about the technology while 25% of the non-users were deterred by biogas installation costs. The average biogas consumption of each household was from 496 to 566 m3 yr−1 for cooking and from 106 to 124 m3 yr−1 for lighting. Biogas user households consumed fuelwood and crop residue to the same extent as non-user households for baking foods. However, biogas user households differed significantly from non-user households in biomass fuel use for non-baked foods owing to the suitability of biogas stoves. Each biogas user household reduced their fuelwood and charcoal use by about 2410 kg yr−1 and 379 kg yr−1, respectively, and decreased their kerosene use (for lighting) by about 9.5 L yr−1. The GHGs emitted by each household was estimated at 10,242 kg CO2e yr−1 and 16,266 kg CO2e yr−1 for biogas user and non-user households, respectively. Thus, each household with a biogas digester has the potential to reduce 6024 kg CO2e yr−1 of GHG emission. Biogas energy can offer an opportunity to mitigate GHGs emissions through reduced pressure on forests. Its’ contribution can more than double by improving the biogas stove design to fit the traditional baked foods.

In the arid, low biomass producing areas of Ethiopia, Acacia woodlands suffered a severe degradation due to exploitation for various uses, and conversion to grazing and cultivated lands. However, little is known on the impact of agricultural land uses on soil organic carbon (SOC), total nitrogen (TN) stocks, and other soil quality indicators. This study was planned to evaluate SOC and TN stock changes under parkland agroforestry (PAF), managed pastureland (MPL), and treeless cropland (TLCL) regimes by considering the remnant protected woodland (PWL) as a reference. We found that SOC and TN stocks were significantly higher in PWL and MPL areas. Conversion of Acacia woodlands to MPL, PAF, and TLCL resulted in the loss of SOC stock by 23, 50, and 56%, respectively. Higher SOC and TN stocks were found under PWL (144.3 Mg ha−1) and MPL (108.2 Mg ha−1). Significant changes in available phosphorous (P), exchangeable cations, and cation exchangeable capacity were observed following the woodland conversion...

Growing trends in industrialization in Ethiopia have raised concerns about pollution of water bodies particularly of lakes. This study was therefore conducted to 1) characterize the chemical contents of major industrial effluents (namely textile ceramic and soft drink factories) that reached Lake Hawassa and 2) investigate the effects of the above mentioned factory effluents on survival of larvae fish and growth of algae. Effluent samples were collected from the outlet lagoons of each factory in December, 2009. Then, effluent samples were analyzed for total N, NO3-N, NH4-N, S2-, , , COD, total dissolved solids (TDS) and heavy metals at the federal Environmental Protection Agency (EPA) Laboratory, Addis Ababa. The experiments on the impact of effluents on survival of fish larvae and growth of algae were conducted using six concrete paved ponds (with different concentration of effluent). The results of chemical analysis showed that textile effluent had high COD (nearly 3 times higher), TDS (19 times higher) as well as (39 times higher) than the maximum permissible limits (MPL) set by Environmental Protection Authority (EPA). Among heavy metals, Zn and Fe of textile effluent were much higher (41 and 1.5 times higher, respectively) than the MPL set by EPA. Ceramic effluent also contained high concentration of (24.5 times), S2-, (2 times) and Zn (14 times) exceeding the limit of EPA. Regarding soft drink factory, high values of COD, and Zn were found in the effluent than the limit specified by EPA. The biological treatment lagoons of the respective source were not effective since the effluents were taken from the last treatment lagoon (outlet lagoon) and some of the measured parameters were higher than MPL. Results of the pond experiment showed that 5%, 10% and 20% concentration levels of the HTF effluent killed significantly high proportion of the fry (65%, 86.8% and 88.7%, respectively). In contrast, fry mortality in ceramic and soft drink effluent treatments, even at 10 and 20% concentration levels, stayed nearly below 10%, which were not far off from the mortality of the control groups. Algal biomass in the treated ponds varied with the type of effluent treatment and concentration level. Compared with the first day, chlorophyll “a” concentration measured on the 7th day had increased by 51%, 48%, 74%, 27% and 31% at 0%, 1%, 5%, 10% and 20% concentrations, respectively of textile effluent. The 5% treatment level of textile effluent caused the highest rate of algal growth above the growth rate observed in the control pond, but further increased in concentration to 10% and 20% resulted in a lower growth of algae than in the control pond. Therefore, textile effluent may boost up algae growth at lower concentrations (~5%) but at higher concentration levels its toxic effect may become inhibitory. Regarding the effluent of soft drink factory, algal growth progressively diminished with increasing concentration of the effluent. The overall change (between initial and day 7) in chlorophyll “a” concentration was highest in the control pond (36.2%) and decreased with increasing effluent concentration (1% to 20%) from 21.7% to -9.4%. On the other hand, algal growth under ceramic effluent treatment was comparable with that observed in the control pond.