Central Rift Valley Of Ethiopia Research Articles

Yield and Quality Response of Snap Bean (Phaseolus vulgaris L.) to P and S Fertilizers Application under Different Irrigation Regimes in Central Rift Valley of Ethiopia

Snap bean (Phaseolus vulgaris L.) is a leading exportable vegetable crop and it is a protein source for consumers in many parts of Ethiopia. However, its’ current national productivity of 4.12 t ha -1 is lower than its’ potential as a result of inadequate moisture and poor soil fertility. Therefore, the field experiment was conducted at Melkassa Agricultural Research Center during the dry season in 2017 and 2018 to evaluate the response of snap bean to phosphorus and sulfur fertilizers application under different irrigation regimes on yield and quality. The experiment was laid out in split-plot design with three replications. Four drip irrigation regimes (100, 85, 70 and 55% ETc) were assigned to main-plots. Four fertilizer types (0, 21 kg P ha -1 , 30 kg S ha -1 and 21 kg P ha -1 +30 kg S ha -1 ) were allocated to sub-plots. The analysis of variance revealed that the interaction effect of irrigation regimes and fertilizers application had a significant (P ≤ 0.05) effect on first grade and total pod yield. The main effect of various irrigation regimes had a significant (P ≤ 0.05) effect for all yield and quality parameters except, second grade pod yield and pod diameter. On the other hand, application of different fertilizers types had non-significant effect in all parameters. The highest marketable yield was recorded from the interaction effect of 100% ETc with different fertilizers types’ application. The partial budget analysis indicated that the best treatments were 85 and 100% ETc without fertilizers application, which gave higher net benefits of 111,879.2 and 160,242.6 ETB ha -1 , respectively with an acceptable marginal rate of returns for snap bean production. Therefore, snap bean producers could consider 85% ETc without fertilizers application where scarcity of irrigation water is limiting and 100% ETc without fertilizers application where there are no water shortages, in the central rift valley of Ethiopia with similar soil properties. Keywords: fertilizers, irrigation, plati, yield DOI: 10.7176/JNSR/12-15-03 Publication date: August 31 st 2021

Response of Onion (Allium Cepa L,) to Different Irrigation Levels Under Conventional Furrow Irrigation With and Without Mulch at Melkassa , Central Rift Valley of Ethiopia

Water is a scarce resource in Central Rift Valley of Ethiopia and is a major limiting factor for crop production. Onion is one of the major economically important vegetable crops grown under irrigation in central rift valley. The field experiment was conducted at Melkasa agricultural research center during the dry season to identify conventional furrow irrigation and irrigation application level with and without mulch that maximizes productivity of onion per unit of water consumed and enhanced onion crop production. The experiment was carried out using RCB design having six treatments with three replications. The FAO’s recommended allowable Manageable depletion level of onion is 100%. In this study 75%, 100% recommended and 125% were tested. The analysis of variance for the result of the study indicated highly significant (P ≤ 0.05) differences for yield, yield components and WUE’s. The highest yield of 320.7 ton/ha was obtained from the 75%MAD with mulch which was not significantly (P ≤ 0.05) different to the 100%MAD irrigation level. In terms of irrigation and water use efficiency, 75%MAD irrigation level application gave the highest IWUE which was significantly different from all other treatment combinations. Yield and water use efficiency based comparison had shown that there was significant difference between the yield, CWUE, and IWUE obtained in the treatment. Therefore, it can be concluded that increased water saving and associated water productivity through the use of 75%MAD with Conventional furrow irrigation and mulch, can solve problem of water shortage which improve WUE without significant reduction of yield.75%MAD irrigation level water applied system and mulch appears to be a promising alternative for water conservation and labor saving with negligible trade-off in yield. Keywords: Furrow irrigation, MAD, Onion, Water productivity DOI: 10.7176/ALST/89-03 Publication date: August 31 st 2021

English

A detailed study on soil resources characterization based on the understanding of the soil system is not available at Dugda district. With the cognizance of this fact, the present study was conducted to characterize the morphological and physicochemical properties of soils, classify the soils according to World Reference Base for Soil Resources (WRB) of Argo-Gedilala Subwatershed in Dugda District of Oromia Regional State, Central Rift Valley of Ethiopia. Four slope classes were considered and one pedon was opened for each and described in the field on a standard description sheet for each slope category. Soil samples were collected from genetic horizons of each pedon for laboratory analysis of the selected physicochemical properties of the soils. The soils were classified into different Reference Soil Groups following the (WRB).The organic carbon (OC) content of the study area ranged from low to medium/moderate (0.64 to 1.83%). Total nitrogen (TN),available.phosphorus (Av.P), cation exchange capacity (CEC) and  percent base saturation (PBS) of the soils were in  the range of (0.066-0.135%), (2.24-4.81 mgkg-1), (39.52-43.52) cmol(+)kg-1) and (77.57- 89.8%), respectively. Accordingly, they were rated as low to medium, very low to low, high to very high and high to very high, respectively. The soil classification revealed that pedon 1 and pedon 2 were Cambic Chernic Phaeozems (Pantoclayic, Humic, Hypereutric); and pedon 4, Cambic Chernic Phaeozem (Pantoclayic, Humic); whereas, pedon 3 is found to be a kind of Luvic Phaeozem (Abruptic, Albic, Clayic, Differentic, Hypereutric). The soils of the study area had low organic matter, available P and total nitrogen content, which can be seen as production constraints of all cultivated lands. To overcome the identified limitations, increasing the organic matter levels through continuous application of manure. Key words: Genetic horizons, morphological properties, pedon, physicochemical properties, slope.

English

Detailed study on soil fertility assessment based on the understanding of the soil system are not available for the most part of Ethiopia. With the cognizance of this fact, the present study was conducted to assess the soil fertility status and to prepare the fertility map of Argo-Gedilala Sub watershed in Dugda District, Central Rift Valley of Ethiopia. Eighteen composite soil samples (0-20cm depth) were taken for fertility assessment of the soil from the land mapping units of the subwatershed and mapping the status of selected soil fertility parameters was done using ordinary kriging technique in ArcGIS 10 software. The bulk density is at an acceptable range 1.3 to 1.4 g cm-3 for mineral agricultural soils. The soil organic matter contents of LUs (04, 05 and 06) 680.47 ha (64.77%) in the study area can be categorized in the range of low soil organic matter content and LUs (01, 02 and 03) 369.31 ha (35.23%) can be categorized in the medium range at the sub-watershed. The average percent total N content of the LUs (02, 04, and 05) 567.7ha (54.05%) were found to be low; LUs (01, 03 and 06) 482.61ha 45.95%) were found to be moderate. The mean available P of soils of LUs (04and05) 443.17 ha (42.19%) was categorized as very low range and LUs (01, 02, 03 and 06) 607.15 ha (57.82%) classified as low range. Exchangeable Ca2+, LUs (01, 02, 03, 05 and 06) 824.88 ha (78.55%) were very high while LU04 which covered an area of 225.44 ha (21.46%) were rated as high. The soils of the study area had low organic matter, available P and total nitrogen content, which can be seen as production constraints of all cultivated lands. To overcome the identified limitations, increasing the organic matter levels through continuous application of manure and/or compost should be integrated with chemical fertilizers.   Key words: Fertility status, land-mapping units, ordinary kriging.

Ripening Response of Sugarcane Varieties to Chemical Ripeners and Economic Benefits during the Early Period of Harvesting at Wonji-Shoa and Metahara Sugarcane Plantations, Central Rift Valley of Ethiopia

Wonji-Shoa and Metahara sugarcane plantations experience reduced sucrose content (%) during the starting period of sugarcane crushing due to the combined influence of high (>27°C) temperature and the presence of high residual soil moisture. Studies elsewhere showed the potential of chemical ripeners in boosting the sucrose content (%), where natural ripening is deterred by these challenges. Accordingly, a field experiment was conducted to evaluate the responsiveness of selected sugarcane varieties to chemical ripeners at both plantations. The treatments consisted of a factorial combination of four sugarcane varieties (B52298, NCo334, C86-56, and SP70-1284) and six ripener treatments: (1) Ethephon™(720 g ai ha−1), (2) Fusilade Forte™(25.6 g ai ha−1), (3) Moddus™ (250 g ai ha−1), (4) Ethephon™ (720 g ai ha−1) + Fusilade Forte™ (25.6 g ai ha−1), (5) Moddus™ (250 g ai ha−1) + Fusilade Forte™ (25.6 g ai ha−1), and (6) Unsprayed (control). The experiment was laid out in a randomised complete block design in a factorial arrangement with three replications. The results showed a significant ( p = 0.025 ) and highly significant ( p = 0.001 ) variety by ripener interaction in stalk height and sucrose content, respectively, while the main effect ripener highly significantly affected stalk weight ( p = 0.001 ) and sucrose yield ( p = 0.003 ). The variety C86-56 sprayed with combinations of Ethephon™ + Fusilade Forte™ and Moddus™ + Fusilade Forte™ had the shortest stalk heights of 1.27 and 1.29 m, respectively, compared with the control. Ethephon™ + Fusilade Forte™ combination resulted in the highest reduction of stalk weight (8.36%), while the lowest was recorded in the sole Moddus™ treatment (6.31%). From the ripener treatments, the Moddus™ + Fusilade Forte™ combination and Ethephon™ + Fusilade Forte™ combination improved sucrose yield by 1.42 and 1.34 t ha−1, respectively, compared with the control. However, in economic terms, the Moddus™ + Fusilade Forte™ combination treatment resulted in the highest marginal rate of return of 1244%. Therefore, the Moddus™ + Fusilade Forte™ combination ripener treatment was found to be promising to be evaluated at a commercial scale on immature sugarcane varieties B52-298, NCo334, and SP70-1284.

Impact of water resource development plan on water abstraction and water balance of Lake Ziway, Ethiopia

Lake Ziway is providing water for a wide variety of sectors in the central rift valley of Ethiopia. However, there is a lack of systematic study that informs the effect of water abstraction on the lake water balance. In the present study, we conducted a Water Abstraction Survey (WAS) to estimate actual water withdrawal from the lake and developed a water balance model of the lake to evaluate the associated impact on the lake water storage and outflow for three development plans. The mean error and root mean square error of the simulated lake water level as compared with observed counterparts were estimated as 0.1 and 0.2 m, respectively, which is smaller than the range of the observed fluctuation of the lake water level under natural condition. Our findings indicate that the actual storage and outflow of Lake Ziway are significantly impacted by the existing water withdrawal. When the future development plans are fully implemented, the annual amount of irrigation and domestic water withdrawal from the lake will reach 95 Mm3. This will cause the lake water level to drop by 0.94 m, which translates to 38 km2 reductions in the lake surface area. Consequently, the lake will lose 26.5% of its actual storage volume when the future development plan (2029–2038) is implemented as compared to the observed storage between 1986 and 2000. Hence, the current impact of water resources development around the lake is substantially large and will exacerbate in the future. This indicates the need for urgent actions to monitor and manage water abstraction from the lake.

Ecotourism Potential Assessment of Dhera Dilfekar Block, Arsi Mountains National Park, Eastern Central Rift valley of Ethiopia

Ethiopia holds substantial ecotourism potentials that have to be promoted for economic development. This study was done with the objective of assessing ecotourism potentials of Dhera dilfekar block for ecotourism development. Dhera dilfekar block is one of the four blocks of Arsi Mountains National Park. Seven (7) major tourist attraction sites were identified namely; Dire kiltu hyena valley, Dire kiltu lesser kudu site, Dire kiltu greater kudu site , Fachiso greater kudu site , Gara dima hyena valley(1), Awash bishola dhagaa taa’aa valley and Gara dima hyena valley(2) .Additionally, the park can offer the visitor an opportunity to see lowland game species, a variety of bird species, Acacia dominated plant species with spectacular landscape, historical and Cultural sites which make the parks unique features to attract eco tourists. The block is the nearest to Addis Ababa (Finfinne) from any other Parks of our country and is found on the main asphalt road which goes to Bale Zone via Adama-Asella. Dhera dilfekar block is found in the lowland that situated in altitudinal elevation ranges from 1300 masl to 1835 masl. This makes the block to be visited all over the year for both domestic and international tourists since there is no mud to travel by vehicle and on foot. The proximity to Sodere resort hotel also brings additional opportunity to be visited by both domestic and foreign tourists. It can be concluded that the area is endowed with high Ecotourism potentials. It can also be good potential for bird watching tourism that can integrate economic gain with biodiversity conservation. Hence, urgent conservation measures and further detail research is recommended to promote this Ecotourism potentials. Key words :Ecotourism, Arsi Mountains, Potential, Dhera dilfekar, Attraction DOI: 10.7176/JTHS/55-01 Publication date: March 31 st 2021

Diversity and Threats of Avifauna in Cheleleka Wetland, Central Rift Valley of Ethiopia

This study was conducted in Cheleleka Wetland, Central Rift Valley of Ethiopia to assess Species diversity and threats of aviafuana from August to February 2019. Data were analysed by using Simpson’s and Shannon-Weiner Index in analysing biodiversity indices. One way ANOVA was applied for analysis of the effect of season on the composition and abundance of species. Questionnaire surveys, key informant interviews and focus group discussion were also used to determine the threats of avifauna in the study area. The result indicated that 49 avian species record under 21 families and 10 orders during both the wet and dry seasons. The Shannon-Weiner diversity index shown that highest bird species diversity (H’=3.42) was recorded during wet season. Over grazing, agricultural expansion, settlement and sand extraction were the major avifaunal threats in the wetland. The result suggests that the need to conserve the avifauna through the conservation of their habitats by creating awareness to the local people and it will enable to decrease biodiversity threats.

Optimal Irrigation Scheduling for Pepper (Capsicum annuum L.) at Gidara Condition, Central Rift Valley of Ethiopia

The wise use of irrigation water relies on understanding the exact crop water demand and its application which help to boost agricultural water productivity. Proper irrigation scheduling comprises crop water demand and the rifling frequency of the required water amount. Therefore, this activity was aimed at determining the optimal irrigation regime for pepper. The trial was carried out during 2016 and 2017 to determine the optimal irrigation regime of Pepper (Mareko Fana variety) at Gidara trial site of Melkassa Agricultural Research under five soil moisture depletion levels at which the next irrigation is given: 60% ASMDL, 80% ASMDL, 100% ASMDL, 120% ASMDL and 140% ASMDL). The allowable soil moisture depletion level (100% ASMDL) was scheduled to be refilled when 30% of the total available soil moisture was depleted. The result revealed that there was significant difference in plant height, yield and water productivity among treatments at 5% level of significance. The maximum yield and water productivity were observed in 60% ASMDL treatment. Using depletion levels of 60% and 80% of the recommended soil moisture depletion levels has increased the water productivity significantly. Hence, as much as the total water to be applied throughout the growth period is similar it is better to irrigate pepper frequently with smaller amount. Keywords: Allowable soil moisture depletion level, Irrigation interval, Irrigation regime, Pepper, Water productivity DOI: 10.7176/JNSR/12-4-01 Publication date: February 28 th 2021

Maize Yield and Water Use Efficiency Under Different Irrigation Levels and Furrow Irrigation Methods in Semiarid, Tropical Region

Water scarcity is the major limiting factor of agricultural production and productivity in the central rift valley of Ethiopia. Best use of limited water is necessary through water conservation practices. Field experiments were conducted during the dry cropping seasons of 2016 and 2017 on clay loam soil at experimental farm of Melkassa Agricultural Research Centre to evaluate the impact of irrigated furrow methods and deficit irrigation applications on maize (Zea mays) yield and water use efficiency. The study involved three furrow irrigation methods (conventional, fixed, and alternate furrow irrigation) and three irrigation application levels (100%ETc, 75%ETc, and 50%ETc). Furrow irrigation system as main plot and irrigation levels as sub-plot were arranged in split plot design with three randomized complete blocks each year. Greatest yield was obtained under conventional furrow irrigation supplied with 100%ETc of water. Water use efficiency under the same treatment was lesser and shows no significant difference with fixed furrow irrigation and 50%ETc application. Greatest water use efficiency of maize was obtained from alternate furrow irrigation under 75%ETc application and showed no significant difference with 100%ETc application. However, grain yield reduction under 75%ETc applications was very much higher than 100%ETc application. Water saved as a result of 100ETc and 75%ETc applications were 50% and 62.5%, respectively. Therefore, scheduling irrigation time for maize in the central rift valley of Ethiopia and similar semiarid environments could be 100%ETc or 75%ETc application using alternate furrow irrigation. The 75%ETc application has an advantage over 100%ETc applications in saving more water and hence could be applied when water availability is severely limited.

Response of Onion (<i>Allium Cepa</i> L,) to Different Irrigation Levels under Conventional Furrow Irrigation with and without Mulch at Melkassa, Central Rift Valley of Ethiopia

Water is a scarce resource in Central Rift Valley of Ethiopia and is a major limiting factor for crop production. Onion is one of the major economically important vegetable crops grown under irrigation in central rift valley. The field experiment was conducted at Melkasa agricultural research center during the dry season to identify conventional furrow irrigation and irrigation application level with and without mulch that maximizes productivity of onion per unit of water consumed and enhanced onion crop production. The experiment was carried out using RCB design having six treatments with three replications. The FAO’s recommended allowable Manageable depletion level of onion is 100%. In this study 75%, 100% recommended and 125% were tested. The analysis of variance for the result of the study indicated highly significant (P ≤ 0.05) differences for yield, yield components and WUE’s. The highest yield of 320.7 ton/ha was obtained from the 75% MAD with mulch which was not significantly (P≤0.05) different to the 100% MAD irrigation level. In terms of irrigation and water use efficiency, 75% MAD irrigation level application gave the highest IWUE which was significantly different from all other treatment combinations. Yield and water use efficiency based comparison had shown that there was significant difference between the yield, CWUE, and IWUE obtained in the treatment. Therefore, it can be concluded that increased water saving and associated water productivity through the use of 75% MAD with Conventional furrow irrigation and mulch, can solve problem of water shortage which improve WUE without significant reduction of yield. 75% MAD irrigation level water applied system and mulch appears to be a promising alternative for water conservation and labor saving with negligible trade-off in yield.

Estimation of Reference Evapotranspiration by Using Different Five Empirical Models for Melkassa Area, Central Rift Valley of Ethiopia

Accurate estimate of reference evapotranspiration is essential for water resource and irrigation project planning and operation that include optimal irrigation scheduling. The study was conducted at melkassa the aim of the study was to estimate reference evapotranspiration of Melkassa area using five different empirical models. Evapotranspiration of the crop and reference evapotranspiration are affected by the climatic parameters like temperature, sunshine duration, humidity, wind speed, solar radiation and so on. Hence, all available climatic data gathered and the estimation of reference evapotranspiration of the area calculated based on five models used. ETo computed by The Blaney-Criddle method, Modified penman method, Radiation method, Throntwaite method and Hargreaves equation. From the result Thornthwaite method gave the maximum rate of Reference evapotranspiration (264.7 mm/month) which is over estimated. The Blaney-Criddlemethod provided the smallest reference evapotranspiration rate (83.7 mm/month). Moreover, the Modified Penman method showed relatively high estimation next to Thornthwaite method and it consists of the energy (radiation) terms and the aerodynamic (wind speed and relative humidity) terms which increased the method to be suggested for the area. The Radiation method showed better evapotranspiration next to Modified Penman method it is the best alternative in the presence of measured wind speed and air humidity data.

Runoff and Sediment Yield Modeling of Meki River Watershed Using SWAT Model in Rift Valley Lakes Basin, Ethiopia

Loss of soil fertility in agricultural lands and sedimentation in lakes of central rift valley of Ethiopia are major watershed problem threatening the agro economy in the area. To develop effective erosion control plans through implementing appropriate soil conservation practices, runoff and sediment yield in Meki watershed was estimated and analyzed using the SWAT model. The model showed the simulated mean annual surface runoff was 114.03mm and the mean annual streamflow was 9.41m³/s. Similarly, mean annual sediment load of 13.12 t/ha enters to Lake Ziway. The model was calibrated and validated on daily and monthly time step for flow and on monthly time step for sediment yield. The results of Nash Sutcliff Efficiency of 0.71 on daily and 0.89 on monthly time steps for streamflow and its value of 0.80 on monthly time step for sediment yield during calibration showed that there is a good match between measured and simulated data for both variables on daily basis and very good match on monthly basis. The potential erosion source areas were identified. Likewise, 51.34% of the watershed area was found to be potential erosion sources and priorized for erosion control plans.

Response of Maize (Zea Mays L.) To Soil Moisture Stress Condition at Different Growth Stages, Central Rift Valley of Ethiopia

Water resources availability is a crucial limiting factor for crop production in arid and semi-arid area. Consuming these limited resources carefully and efficiently is unquestionable. The planning of irrigation permitting to the water stress tolerance and water use efficiency of crops remains the only way to guarantee the continuity of production in an arid area. Considering this an experiment has been conducted in Melkassa Agricultural Research Center where shortage of moisture is a problem. The experiment was laid out in RCBD with three replications having 15 experimental treatments. The treatments had four crop growing seasons or stages (Initial, Development, midseason and late season stages. Melkassa II maize variety was used for seed materials. Water stress had significant different effect on grain yield, above ground dry biomass, plant height and water productivity (P 0.05) difference in grain yield among treatments stressed only at initial stage, late stage and non-stressed. However, stressing of maize at development and mid-season crop growth stage led to significant reduction of grain yield, above ground dry biomass and plant height. Therefore, stressing maize at combination of development stages and mid stages was more sensitive with significant yield penalty.

Review of Soil Erosion Risk For Soil and Water Conservation Planning Under Ethiopian Condition

Soil erosion is one of the major factors affecting sustainability of agricultural production in Ethiopia. This paper reviews Ethiopia’s experience and research progress in soil erosion risk for Soil and Water Conservation planning. In most findings conducted at Ethiopian watershed possibilities of high soil lose and risk was reported. Their findings revealed that the study areas are facing different problems such that forest transformation, which is very likely intensified by the demand for subsistence agricultural land. Most of the parts of these watersheds have experienced intensive soil erosion behavior, which is beyond the tolerable soil loss level. This threatens the annual crop production and the productivity of the land impacting the local farmers’ food security. Analysis of a compilation of soil loss rates due to sheet and rill erosion at plot and catchment scales indicates that this soil degradation process varies strongly spatially, with a mean soil loss 29.9 t ha −1 yr −1.The highest rates were observed in Anjeni (110 t ha −1 yr −1) and Chemoga (102 t ha −1 yr −1) of the Upper Blue Nile Basin. Studies in the northern Ethiopian highlands and the Central Rift Valley of Ethiopia reported larger erosive power of rainfall as compared to elsewhere in the world.FAO (1986) estimated of gross annual soil loss nationwide of 1.9 × 10 9 t of which 80% originates from croplands. Hurni (1988) estimated a nationwide annual gross soil loss of 1.5 × 109 t, extrapolating data obtained from six SCRP research stations in which the highest loss is from croplands (42 t ha −1 yr −1 ). Sonneveld et al. (2011) provided a tentative nationwide mean annual soil loss map combining the results of different model estimates. They stated that soil loss varies remarkably from 0 t ha −1 yr −1 in the eastern and southeastern parts of Ethiopia to more than 100 t ha −1 yr −1 in the northwestern part of the country. Hence, review on identifying and prioritizing erosion susceptible areas for soil conservation measures are quite essential. Reviewing or quantifying the effects of the soil loss helps to substantiate investment in sustainable land management for the benefits to land users. Appropriate soil conservation measures bring economic advantages to the land users. Review on amount of soil loss and the status of the existing soil conservation measures can be realistic for farmers and policy makers if expressed in terms of understandable value.

Genotype by Environment interactions for egg number and egg weight of five dual-purpose chicken breeds in different zones of Oromia region in Ethiopia

The African Chicken Genetic Gain (ACGG) project (https://africacgg.net/) aims at backyard poultry optimization by commercial dual-purpose breeds introduction into Africa. To measure benefits, genotype by environment interaction (GxE) analysis provides guidance while predicting environmental effects on production traits of breeds. A survey among Ethiopian poultry smallholders showed egg sale being the most important purpose of keeping village chickens in Oromia. Data was available about laying of 894 ACGG chickens in Oromia. Hence current research questions were: 1) Does GxE take place? 2) Which breed performs best regarding laying and in which environment within Oromia? Traits investigated were egg number and egg weight of five breeds (S-RIR, Sasso, Horro, Kuroiler and Koekoek) located in three zones (East Hararge, East and West Shoa) and 5 districts (Adami Tulu, Bako Tibe, Dano, Dugda and Haromaya) in Oromia. Observations were taken as group measure performing weighted analyses. GxE was only present for egg number with magnitude strongest for zone. S-RIR performed best for both traits in both environments, except Kuroiler performing better in East Shoa for egg number and Koekoek for egg weight. This indicates success of crossbreed S-RIR. Sasso and Horro performed worst supported by previous research for Horro but not Sasso. Low precipitation in East Shoa caused bigger distance in egg number predictions, being higher for S-RIR and lower for Horro and Sasso compared to West Shoa. Apart from these final conclusions, social context of breeding and data collection difficulties should not be forgotten. Just like relevance of other performance trait analyses.

English

Recently Green bean production and demand is increasing in Ethiopia due to its fast maturity and nutritional value. However, various constraints are reported for its low productivity, including inappropriate uses of plant population and fertilizer rates. The objective of this study was to determine the optimum plant population and NPS rate for quality and economically feasible yield of Green bean. The experiment was conducted in field conditions at Alage, Central Rift Valley of Ethiopia, under supplemental irrigation in 2019. A factorial combinations of three plant populations (222222, 250000 and 333333 plants ha-1) and five levels of blended NPS (0, 132, 142, 152 and 162 kg NPS ha-1) were used in a randomized complete block design (RCBD) with three replications. Number of nodules per plant, number of effective nodule per plant, number of leaf per plant, plant height, and number of branches per plant, number of pod per plant, total above ground fresh biomass, pod diameter, pod length, harvest index and yield per plant and per hectare were recorded. All parameters were subjected to analysis of variance. The least significant differences (LSD) at the level of 5% significance were used to compare the treatments mean. The results showed that plant population and NPS rates had significant effects on number of nodules, number of leaf, number of branch, plant height, number of pod, pod length, harvest index, yield per plant and per hectare. The highest Green bean yield of 13.75 tons ha-1 and 16.06 tons ha-1 was obtained at the highest plant population (333333 plants ha-1) and the highest NPS rate (162 kg NPS ha-1), respectively. The highest acceptable marginal rates of return (57349%) and (6997.2%) were obtained from 333333 plants ha-1 and 162kg NPS ha-1, respectively. Thus, it can be concluded that 333333 plants ha-1 and application of 162kg NPS ha-1 were gained the superiority for both agronomic and economic growth and productivity for plati variety of Green bean under supplementary irrigation at Alage area. Key words: Green bean, plant population, NPS fertilizer rate, growth, yield.

Enset-based land use land cover change detection and its impact on soil erosion in Meki river watershed, Western Lake Ziway Sub-Basin, Central Rift Valley of Ethiopia

BackgroundWater erosion, upland degradation and deforestation are key environmental problems in the Meki river watershed. The study assessed the land use land cover change (LULCC) for 30 years and it examined the contribution of indigenous Enset-based land use system (EBLUS) to reduce soil erosion and prevent water bodies including Lake Ziway from sedimentation which was not considered in the former studies. GPS based data collected and satellite based LULC analysis using ERDAS Imagine 2014 performed to investigate existing farm management practices and land cover respectively. HEC-GEOHMS, Geo-statistical interpolation and RUSLE were applied to model watershed characteristics, spatial climate parameters and soil loss respectively.ResultMeki river watershed (2110.4 km2 of area) is dominantly covered by cultivated LUS (41.5%), EBLUS (10.65%), Bush and Chat LUS (25.6%), Forest and plantations LUS (14.14%), built-up (7.4%) and water bodies (0.75%). Soil loss is increasing from 1987 to 2017 and a larger part of the watershed suffers a moderately severe to very severe risk (18 t ha−1 year−1 to > 80 t ha−1 year−1) in all sub-watersheds irrespective of the land use systems which shows the watershed is facing sever degradation problem. The mean soil loss of 30.5 t ha−1 year−13 and 31.905 t ha−1 year−1 are verified from Enset growing zones and non-Enset growing zones of the watershed respectively.ConclusionEBLUS saves significant amount of soil despite the steepness of the slopes of the Enset growing zones of the watershed. Hence, expansion of EBLUS can contribute in sustaining water bodies, including Lake Ziway by reducing soil loss rate and sedimentation problem for the ecological sustainability of the watershed. Therefore, separate land use policy and awareness creation are mandatory for such EBLUS expansion, sustainable watershed management interventions and conservation of the natural environment in the watershed based on its suitability and severity of erosion risk mapping.

Regional variation in susceptibility of thrips (Thysanoptera: Thripidae) to insecticides on onion in the Rift Valley of Ethiopia

The responses of thrips to commonly used insecticides were studied in onion fields with the aim of detecting presence or absence of thrips resistance to insecticides in the Central Rift Valley of Ethiopia. Thrips populations were collected from area with heavy pesticide use history Meki and Melkassa and less use areas of Werer and Minjar. Collected adult thrips populations were exposed to various concentrations of λ -cyhalothrin, dimethoate, profenofos, diazinon and spinetoram treated vial and thrips mortality was assessed after 24 h. The percent mortality was significantly lower in Meki and Melkassa collected thrips populations than in Minjar and Werer populations to λ –cyhalothrin and diazinon at recommended field rate. On the other hand, differences were insignificant for the insecticides spinetoram and profenofos at recommended field rate. Of the five tested insecticides λ –cyhalothrin had higher resistance ratios to Meki (10.8-fold) and Melkassa (6.78- fold) collected thrips population, while resistance ratio was intermediate to diazinon and lowest to dimethoate and profenofos insecticides. Results of this study suggest that thrips affecting onion in Meki and Melkassa areas have developed resistance to λ –cyhalothrin and diazinon insecticides. Periodic assessment of efficacy of registered insecticides and deploying a pesticides resistance management strategy are useful for sustainable use of pesticides in integrated thrips management program.

Diet composition and preferences of Bohor reedbuck (Redunca redunca ) in the compound of Alage College, Central Rift Valley of Ethiopia.

Numerous indices have been developed to compare use and availability of foods in field diets of wild ungulates. However, little attention has been given to laboratory analysis for comparing food preferences. To this end, a study aimed at investigating the diet composition and preference of Bohor reedbuck was conducted in the compound of Alage Agricultural College, Central Rift Valley of Ethiopia from 2017 to 2018 encompassing both dry and wet seasons. Bohor reedbuck is a medium sized horned antelope species endemic to Africa. Continuous focal animal observation was used to collect the data on plant species included in the diet of Bohor reedbuck. Focal individuals’ observation was carried out for 30 min in 10 min sampling interval during their active feeding period (early morning and late afternoon) over four different habitat types. The nutrient composition of plants consumed was determined using wet chemistry laboratory analysis. Bohor reedbucks consumed 15 species of plants; herbs comprised 94.3% of the foods they consumed. Digitaria abyssinica was the most preferred plant species with highest crude protein (23.75%) and less fiber (61.8% nitrogen detergent fiber and 27.8% acid detergent fiber). These findings suggest that food preference of Bohor reedbuck is determined by the nutritional content of the plant it consumed, since the area is more or less natural habitat in terms of plant species composition. For sustainable conservation of the species, there is a need to actively promote management of the plant species most preferred by the reedbuck to feed on.