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Background: Availability of accurate soil data is necessary in understanding the nature of the soil and its status of the agricultural potential. Aim: Thus, a research was carried out to investigate physicochemical and morphological properties of the soils and characterize, classify and mapping them accordingly at Enemor Ener woreda, southern Ethiopia. Methods: Nineteen (19) representative pedons were opened from lower, middle and upper slopes and described them according to WRB (2014). Soil samples from each horizon were analysed for physicochemical properties. Results: Soils in the study area are so variable in their formation and nutrient availability. The major soil textural classes are clay loam and clay. Calcium the most dominant exch. bases whereas, Magnesium, sodium and potassium follow in decreasing order. The soil pH was ranged from strongly acidic to neutral reaction. Total nitrogen and organic carbons contents in all soils of the pedons are low to very low. Phosphorous content was ranged from optimum to very low content. Cation exchange capacity and percentage of the base saturation were ranged from very high to optimum, in regards to the micronutrients such as iron, manganese, copper and zinc in the soils were ranged from sufficient III to sufficient I. Major soil types revealed in the study area are Chromic Luvisols, Haplic Nitisols, Mollic Leptosols and Mesotrphic Vertisols. Conclusion: Soil properties and their potential status influenced by topography and land use type. Therefore, practice of soil integrated fertility management is vital for their sustainability.

Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit. So, choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard. This study was undertaken to assess effects of rootstock and location on quality of orange fruit. The study was conducted over two consecutive years (2017/18 and 2018/19). Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar, Ethiopia at four sites (Abala, Agulae, Adiha and Rama). The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. Data on different physico-chemical and bioactive compounds were collected and analyzed using R software (version 4). Compared to sour orange, rough lemon rootstock revealed higher fruit mass (151.96 g, 195.38 g), fruit length (62.27 mm, 68.88 mm) and fruit diameter (65.58 mm, 71.3 mm), in 2017/18, 2018/19, respectively. Among the four locations (Abala, Agulae, Adiha and Rama), higher juice percentage was found in Adiha (43.47% in 2017/18) and Abala (49.87%, in 2018/19). In 2017/18 higher total soluble solid (TSS, 13.87%), TSS/acid ratio (19.18) and fruit rag (32.77%), were obtained at the Rama site. On the one hand, higher vitamin C (826.6 mg • kg−1) and total phenolic content (208 mg • kg−1GAE) were recorded at Agulae than Abala, Adiha and Rama sites from sour orange rootstock. High TSS, TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site. This was expected to have resulted from hot climate conditions at the site. Besides, at a relatively cooler condition of the Agulae site, high phenolic, reduced ferric power and high vitamin C were recorded. Rough lemon rootstock improved fruit size, while rootstock did not affect the contents of TSS, TSS/acid ratio across the sites in both harvesting years.

Bauhinia thonningii is a woody leguminous tree species, which is endowed with enormous soil improvement, medicinal, nutritional, and socio-ecological benefits in African. The current study was carried out to systematically review and document findings on the multiple benefits of B. thonningii and thereby identify gaps and opportunities for further comprehensive studies. A systematic and manual search was conducted to retrieve relevant articles published from 1974 to June 2021. Electronic databases of PubMed (Medline), Google Scholar, and grey literature were employed to access the studies. Accordingly, 100 articles and 2 thesis papers were finally included in this study. The study shows B. thonningii tree species improve soil fertility and its abundant litter accumulated from the leaves of B. thonningii trees contributed to increased organic carbon and total nitrogen content. The plant parts are used in several traditional medicine to treat different human and animal ailments. The pods and seeds of the plant contained a lot of important nutrients and nutritional value, beneficial to human as well as animal health. The plant plays a key role in biomass production and carbon sequestration potential. Owing to its multiple benefits, there is an urgent need to facilitate the scaling-up of the use of the tree by using various approaches. The findings will serve as a useful reference for further in depth investigations on the multifunctional uses of the plant across different ecozone as well as supporting the scale up of the benefits of the species.

Climate change is expected to alter the growing conditions of agricultural crops. With increasing surface temperature, future suitable areas for crop production will see an altitude shift. Such shi...

Soil Organic carbon (SOC) is vital to the soil’s ecosystem functioning as well as improving soil fertility. Slight variation in C in the soil has significant potential to be either a source of CO2 in the atmosphere or a sink to be stored in the form of soil organic matter. However, modeling SOC spatiotemporal changes was challenging due to lack of data to represent the high spatial heterogeneity in soil properties. Less expensive techniques, digital soil mapping (DSM) combined with space-for-time substitution (SFTS), were applied to predict the present and projected SOC stock for temperature and rainfall projections under different climate scenarios represented by the four Representative Concentration Pathways (RCPs): RCP2.6, RCP4.5, RCP6, and RCP8.5). The relationship between environmental covariates (n = 16) and measured SOC stock (148 samples) was developed using a random forest model. Then, the temporal changes in SOC stock over the baseline were developed for the top 30 cm soil depth of the selected districts (Chiro Zuria, Kuni, Gemechis and Mieso) of West Hararghe Zone at 30 m resolution. The model validation using the random sample of 20% of the data showed that the model explained 44% of the variance (R2) with a root mean square error (RMSE) of 8.96, a mean error (ME) of 0.16, and a Lin’s concordance correlation coefficient (CCC) of 0.88. Temperature was the most important predictor factor influencing the spatial distribution of SOC stock. An overall net gain of SOC stock over the present C stock was expected in the study area by 2050. The gain in areas with the lower baseline SOC stock counterbalanced the loss in areas with the higher baseline stock. The changes in the SOC stock depended on land use land cover (LULC), soil type, and agro-ecological zones. By 2050, cropland is supposed to lose its SOC stock under all RCPs; therefore, appropriate decisions are crucial to compensate for the loss of C.

Marketability and nutritional content are critical factors that need to be considered when a quality of orange fruit is assessed. Among the many factors affecting orange fruit quality, tree age and...

Up-to-date digital soil resources information, and its comprehensive understanding, is crucial to support crop production and sustainable agricultural development. Generating such information through conventional approaches consumes time and resources, which is difficult for developing countries. In Ethiopia, the soil resource map that was in use is qualitative, dated (since 1984), and small-scale (1:2 M) which limits its practical applicability. Yet, a large legacy soil profile data accumulated over time and the emerging machine learning modelling approaches can help in generating a high-quality quantitative digital soil map that can provide accurate soil information. Thus, a group of researchers formed a coalition of the willing for soil and agronomy data sharing and collated about 20,000 soil profile data and stored them in a central database. The data were cleaned and harmonized using the latest soil profile data template and prepared 14,681 profile data for modelling. Random Forest was used to develop a continuous quantitative digital map of 18 WRB reference soil groups at 250 m resolution by integrating environmental variables-covariates representing major Ethiopian soil-forming factors. The validated map will have tremendous significance in soil management and other land-based development planning, given its improved spatial nature and quantitative digital representation.

Conversion of native pasturelands to cultivated land led to a decline in soil fertility resulting in low agricultural productivity. This study attempted to investigate the magnitude and rate of pas...

Even though flooding is a threat to rural communities in plains drained by ephemeral rivers, the magnitude of its impact, coping/prevention mechanisms, and the implications for river management are not well known. In this study, data were collected using a phenomenological‐based research design. Field observations, a questionnaire (n = 440), key informant interviews (10), and one focus group discussion (with seven discussants) were used to collect the desired data from flood‐prone farmers. As the results show, 42% of the respondents believe that flooding has become stronger over the past 20 years, whereas 38% believe there has been no change. As mitigation measures, 52% of the respondents suggested evacuating to neighbouring villages as the best option. Most of the damage was experienced in farmlands (including crops, either harvested or standing) and settlements. As coping mechanisms, 31% of the respondents were displaced, whereas an additional 40% were forced to construct new houses for their settlement. Chi‐square testing showed that the farmers’ responses statistically varied among different groups (p

Establishing model based balanced nutrient requirements for barley (Hordeum spp.) in the northern Ethiopia can solve the fertilizer recommendation problems and enhance crop yield. The Quantitative Evaluation of Fertility of Tropical Soils (QUEFTS) model was used to estimate balanced nitrogen (N), phosphorus (P) and potassium (K) requirements for barley production in Alaje, northern Ethiopia. The objectives were to (i) quantify soil N, P and K supply and recommend fertilizers using QUEFTS model; (ii) investigate response of QUEFTS fertilizer application on yield and nutrient uptake and (iii) validate QUEFTS model performance. The experiment had four treatments: (T1) model based fertilization; (T2) blended fertilization; (T3) farmers’ fertilization practices and (T4) control/no fertilizer. Soil information of the experimental plots were analyzed and used as model input to estimate soil nutrient supplies and recommend fertilizer. Yield and agronomic data were recorded and nutrient uptake and use efficiencies were analyzed. Model performance and accuracy were also checked using root mean square error, coefficient of determination, index of agreement and percent bias. The result revealed that the N, P and K soil supply ratio in the field experimental plots were 9:1:6. The higher grain yield of 4747 kg ha−1 was recorded in the QUEFTS based fertilization plots. Validation results indicated that there is a good correlation between the QUEFTS predicted and observed grain yields implying that the QUEFTS model can be a base for development of simple and cost-effective decision support tools for nutrient management and fertilizer recommendations. Thus, the model performance and prediction accuracy is promising and can help farmers to adjust fertilizer application rates based on crop requirements., fertilizer recommendation; model performance; soil fertility; validation

Farmers in Northern Ethiopia integrate legumes in their cropping systems to improve soil fertility. However, biological nitrogen fixation (BNF) potentials of different legumes and their mineral nitrogen (N) and phosphorus (P) demands for optimum BNF and yields are less studied. This study aimed to generate the necessary knowledge to enable development of informed nutrient management recommendations, guide governmental public policy and assist farmer decision making. The experiment was conducted at farmers&rsquo, fields with four N levels, three P levels, and three replications. Nodule number and dry biomass per plant were assessed. Nitrogen difference method was used to estimate the amount of fixed N by assuming legume BNF was responsible for differences in plant N and soil mineral N measured between legume treatments and wheat. The result revealed that the highest grain yields of faba bean (2531 kg ha&minus, 1), field pea (2493 kg ha&minus, 1) and dekeko (1694 kg ha&minus, 1) were recorded with the combined application of 20 kg N ha&minus, 1 and 20 kg P ha&minus, 1. Faba bean, field pea and dekeko also fixed 97, 38 and 49 kg N ha&minus, 1, respectively, with the combined application of 20 kg N ha&minus, 1, however, lentil fixed 20 kg ha&minus, 1 with the combined application of 10 kg N ha&minus, 1 and 10 kg P ha&minus, 1. The average BNF of legumes in the average of all N and P interaction rates were 67, 23, 32 and 16 kg N ha&minus, 1 for faba bean, field pea, dekeko and lentil, respectively. Moreover, faba bean, field pea, dekeko and lentil accumulated a surplus soil N of 37, 21, 26 and 13 kg ha&minus, 1, respectively, over the wheat plot. The application of 20 kg N ha&minus, 1 levels alone and combined significantly (p &lt, 0.05) increased the nodulation, BNF and yield of legumes, however, 46 kg N ha-1 significantly decreased BNF. This indicated that the combination of 20 kg N ha&minus, 1 levels is what mineral fertilizer demands to optimize the BNF and yield of legumes. The results of this study can lead to the development of policy and farmer guidelines, as intensification of the use of legumes supplied with starter N and P fertilizers in Northern Ethiopian cropping systems has the multiple benefits of enhancing inputs of fixed N, improving the soil N status for following crops, and becoming a sustainable option for sustainable soil fertility management practice.

Understanding the geographical distribution of soils is indispensable for policy and decision makers to achieve the goal of increasing agricultural production and reduce poverty, particularly in the Global South. The soilscapes of the Giba catchment (900-3300 m a.s.l.; 5133 km²) in northern Ethiopia were studied, in support of sustainable soil use and land management. Based on their morphologic, physical and chemical properties, 141 soil profile pits and 1381 additional augered profiles were classified according to the World Reference Base for soil resources. The dominant soil units are Leptosols (19% coverage), Vertic Cambisols (14%), Regosols and Cambisols (10%), Skeletic and Leptic Cambisols and Regosols (9%), Rendzic Leptosols (7%), Calcaric and Calcic Vertisols (6%), Chromic Luvisols (6%) and Chromic and Pellic Vertisols (5%). The soilscapes are best explained by the topography and parent material that are the major factors determining the geomorphic processes in the area. Besides these two factors, land cover that is strongly impacted by human activities, may not be overlooked. Except for the Vertisols and patchy Phaeozems that are stable since the Mid-Holocene, all other soil units in the study area are the result of profile truncation on the one hand, and colluviation more downslope on the other hand. In addition, due to three millennia of soil tillage, lynchets have been formed at many places along the slope, and rock fragments concentrated on the surface, leading to armouring that locally prevents deeper erosion. Our soil suitability study shows that currently, after thousands of years of agricultural land use and concomitant land degradation, a new dynamic equilibrium has come into existence in the soilscape, in which ca. 65% of the catchment remains suitable for agricultural production.

Geotourism combines abiotic, biotic and cultural aspects. In Tigray in northern Ethiopia, the Orthodox Christian religion is a dominant component of culture, that highlights the importance of geology and the wider natural environment, and creates great visibility for it.Hundreds of rock churches have been established in various lithologies, often in very scenic landscapes and are a major tourist attraction in Ethiopia; Around every church in Tembien, a sacred forest is present, remnants of the primary forest, 1 ha up to 1 km² in size. In such a way, the believers try to protect God’s creation; it is also a way to protect the church site from erosion and provide a pleasant microclimate; Numerous, often strong springs are considered as “holy water”, that has the power to cure various diseases; people travel long distances on foot, either to spend a required period of time near the spring, or to obtain water, often mixed with soil that will be carried home; Major churches and “holy waters” are located in remote places; pilgrims follow semi-fixed pilgrim ways, along which basic facilities are established and where riparian people are not surprised by the presence of trekkers; As it has been created by God, there is a general sense for environmental protection, which is evidenced by the numerous birds present, the status of forests, construction of nest boxes for doves (representing the Holy Spirit), or the status of wild animals such as leopards; Underground tunnels, natural caves (Zeyi cave is 364 m long) or caverns in rocks play a crucial role in ancient traditions of the Tigrayan highlanders; their religious use is considered as a christianisation of an earlier sacred spot; There are numerous impressive popular geological myths inspired by religion – for example a fault line that evidences a path of a sacred snake, a petrified marriage party, a 150 Mg rock that was rolled by one Mr. Ilias for sake of church building - the storytelling exemplifies the Tembien Highlands’ geoheritage value; The function of these sacred places as a main destination for domestic tourism contributes to popularising geology in the society. As geosites are so highly valued in local religious beliefs, introducing a secondary function as geosites requires specific challenges to be taken into account, besides the common drawbacks of tourism in developing countries:Problems of access to churches, forests, caves; Gender neutral geotourism vs patriarchal religious attitudes; Conservation vs “modernisation” of rock churches and sacred sites; 4.5 billion years History of Earth vs 6000 years since Genesis; Information boards at geosites: religious narratives vs scientific understanding; Showing appropriate respect to the sacred environment; Preparation of appropriate and site-specific souvenirs; and Community ownership and benefits of geotourism. In Tembien, the local society has preserved sacred geosites which are important for their self-definition as societies protected by divine powers. Mutual respect, openness and a participatory approach are key when sharing the preserved sites to geotourists.

Soil organic carbon (SOC) is the major component of the terrestrial carbon (C) budget, a key indicator of environmental sustainability. So, estimating SOC stock and soil carbon (C) sequestration dynamics is important for evidence-based and carbon-conscious decisions. Quantification of SOC stock and soil C sequestration affected by land-use changes (LUCs) have received much attention in addressing food and climate security. This study aims to estimate the dynamics of SOC stock, soil C sequestration and associated soil parameters affected by major LUCs from 2012 to 2021 in Awi highlands of Amhara Regional State of Ethiopia. The study area has experienced dramatic LUC, particularly plantation and growing of Acacia decurrens (J.C. Wendl.) tree followed by recurrent deforestation and then cropping and back to the plantation. The study quantified spatial and temporal dynamics of SOC stock, soil C sequestration and associated changes affected by the LUCs. A total of 22 topsoil (0–20 cm) legacy data was obtained from the Ethiopian Soil Information System (EthiSIS) database of 2012. The same number of samples were collected at the same locations in 2021 by using the same sampling procedure as that of 2012. In addition, the same number of core samples were collected in 2021 for bulk density analysis. To estimate the unmeasured bulk density of legacy data, we applied a pedotransfer function. We used empirical equations and basic statistics to assess changes in SOC stock and C sequestration rate between the two periods. Statistically significant variation (P

Teff Eragrostis tef (Zucc.) crop production is essential since it is a major food crop in Ethiopia. This paper presents a teff land suitability evaluation model in Northern semi-arid Ethiopia by using GIS-based multi-criteria decision making analysis (MCDMA) in order to identify areas that best suit sustainable production of the crop. The results showed that 37.59, 56.99 and 5.42% of the area are moderately (S2), marginally (S3) and currently not suitable (N1) for teff crop production. Mean weight diameter, available water capacity, total nitrogen, available phosphorus, exchangeable bases, length of growing period and slope are the major constraints causing serious hurdle for teff production. However, with the application of organic and inorganic fertilizer (especially of nitrogen, phosphorus and potassium fertilizers), tillage, soil and water management practices 2.05, 55.85 and 13.51% changes in suitability from N1 to S3, S3 to S2 and S2 to S1 suitability levels respectively is occurred. This indicates that the area is promising if investments in land and soil managements are made though climate and topographic factors supported by some soil physical and morphological properties are permanently limiting its suitability. GIS-based AHP model is superior for land suitability evaluation of teff crop production in areas with various soil and landscape positions.

In the Ethiopian highlands, communal grazing lands are one of the major land uses, and are source of livelihood for the rural people. Free and uncontrolled grazing in the communal grazing lands is the dominant grazing system. The traditional uncontrolled and free grazing system has caused severe degradation of the grazing lands. As a result, communities have started to establish exclosures and support the restoration of degraded communal grazing lands. Studies have shown that exclosures are effective to restoring degraded communal grazing lands and improving ecosystem services. However, studies that investigate the changes in aboveground biomass following the establishment of exclosures and compare it with fuelwood demand of the beneficiaries in our study area is lacking. Therefore, our study aimed at: (1) quantifying yearly biomass accumulation in exclosures and compare it to fuelwood demand of households that manage the exclosures; (2) assessing household energy sources and their consumption levels. To monitor changes in biomass production with over time, replicated (n = 3) 5 and 10 year-old exclosures were sampled. To investigate fuelwood sources and consumption patterns, household surveys, key informant interviews and focus group discussion were conducted. Our results demonstrated that total biomass production increased with exclosure age. In both exclosure, biomass production from Vachellia etbaica was significantly (p

Low mineral fertiliser use received much attention in Africa over the last decades. As fertiliser sales have exponentially grown in Ethiopia, and evidence exists of a supply that is beyond the demand in the drier northern parts of the country, we investigated the geographical determinants of inorganic fertiliser sales and its resale prices in north Ethiopia. Quantitative data on fertiliser provision and prices on the black market in 2016 were obtained from official statistics and from key informants in each of the 35 studied districts and in all municipalities of the Raya area. Environmental variables were collected from spatial databases. To promote inorganic fertiliser, agricultural experts use incentives, and also barter the purchase of fertiliser by a farmer against food aid or other advantages from the authorities. The high application rate that is aimed at (200 kg ha−1) contrasts with the dominance of less-responsive soils in the study area, for which inorganic fertiliser application does not result in higher crop yields, or even leads to root burn. The quantitative analysis shows that 40.7 103 Mg of fertiliser were officially sold in the study area in 2016, which corresponds to 52 kg ha−1. This is notably different from the application rate, as reselling widely occurs, at 50% of the official price for diammonium phosphate (DAP) and 54% for urea, mostly to users outside the community. By accepting the opportunity offered by agricultural companies and traders, smallholders save themselves from greater losses. The black market rate is strongly and positively correlated to monthly rainfall at sowing time (July 2016) (R2 = 0.44; n = 31; p

Transnational land deals are among the most contested but inadequately understood topics. In this paper, we focus on the features of large-scale transnational land deals (LSTLDs) in the Global South through an examination of Ethiopia. We apply a mixed- method (qualitative and quantitative) research design. Results indicate that in 2005-2015, the government leased nearly 2.47 million hectares of the country's total 100 million hectares land area and 11.5 million hectares of agricultural land to domestic and transnational investors. We explore the prevalence of LSTLDs deals by companies of the Global South, particularly entrepreneurs from India. Ethiopia's example validates emerging arguments on the rise of South-South investment deals rather than the established explanation of North-South capital flows. However, 75% of the land deals show poor performance. The study shows that LSTLDs have contributed to raising domestic agricultural production but have resulted in non-performing loans of the banks of the host country. In sum, the land deals have resulted in financial-grabbing, where Ethiopian banks end up with non-performing loans and then must chase investors to settle the approximate € 791 million in loans that investors borrowed for their projects.

Knowledge of the geographical distribution of soils is indispensable for policy and decision makers to achieve the goal of increasing agricultural production and reduce poverty, particularly in the Global South. A study was conducted to better understand the soilscapes of the Giba catchment (900-3300 m a.s.l.; 5133 km2) in northern Ethiopia, so as to sustain soil use and management. To characterise the chemical and physical properties of the different benchmark soils and to classify them in line with the World Reference Base of Soil Resources, 141 soil profile pits and 1381 soil augerings at representative sites were analysed. The dominant soil units identified are Leptosol and bare rock (19% coverage), Vertic Cambisol (14%), Regosol and Cambisol (10%), Skeletic/Leptic Cambisol and Regosol (9%), Rendzic Leptosol (7%), Calcaric/Calcic Vertisol (6%), Chromic Luvisol (6%) and Chromic/Pellic Vertisol (5%). Together these eight soil units cover almost 75% of the catchment. Topography and parent material are the major influencing factors that explain the soil distribution. Besides these two factors, land cover that is strongly impacted by human activities, may not be overlooked. Our soil suitability study shows that currently, after thousands of years of agricultural land use, a new dynamic equilibrium has come into existence in the soilscape, in which ca. 40% of the catchment is very suitable, and 25% is moderately suitable for agricultural production. In view of such large suitable areas, the Giba catchment has a good agricultural potential if soil erosion rates can be controlled, soil fertility (particularly nitrogen) increased, available water optimally used, and henceforth crop yields increased. ispartof: Plos One vol:14 issue:10 ispartof: location:United States status: published

Over the decades, we have witnessed numerous changes in Dogu’a Tembien, not only concerning soil and water conservation, land management, or farmers’ livelihood, but also education or health. For instance, within one generation, female genital mutilation that was widespread has become extinct. Though living standards remain low, the interventions of the developmental bureaucratic state had their effects. Testimonies of improved livelihood are the corrugated iron roofs that have appeared in the landscapes.

With the existence of clearly demarcated fields that are cropped every year, the agricultural system of the Tembien highlands can be characterised as a permanent upland farming system, practised by a sedentary population. Livestock are predominantly cattle (especially oxen) and sheep, goats, donkeys and mules.

Mass movements comprise the sliding, tumbling or falling of rock fragments and fine earth masses, largely under the force of gravity. Mass movement bodies are conspicuous on escarpments and on foot slopes of the tabular ridges of Dogu’a Tembien. Two main types can be distinguished: (1) rockfall resulting in scree slopes and (2) landslides, mostly debris flows. The latter are mainly triggered by the process of (3) argilliturbation, soil churning caused by seasonal swell and shrink of smectite clays in the Vertisols. Argilliturbation leads also to the development of (4) extensive rock fragment covers, especially at the surface of Vertisols and soils with vertic properties.

Given the mountainous character of Dogu’a Tembien along with a strong variability in lithology, topography and climate, a wide range of soil types can be expected. Nevertheless, the occurrence of soil types and sequences (catenas) is all but random.

The Raya graben is located in Tigray, northern Ethiopia, and it is a marginal structural graben of the Red Sea branch of the Ethiopian Rift valley (Fig. 1). The graben is crossed by several rivers, which are dry for the most of the year, and only one perennial, seasonal river. These ephemeral streams originate from the high mountains (highest peak 4003 m asl) on the western shoulder of the graben and dry up in the basin floor where they commonly form large distributary systems (Billi in Geomorphology 85:98–113, 2007). Open image in new window Fig. 1. Raya Graben with study rivers (modified from Demissie et al. 2017).