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26 Farmland management, tillage and resulting cultivation terraces
Abstract
All over Dogu’a Tembien, farmlands appear to be terraced, though there is no evidence of large-scale manual or mechanical levelling of the land, not now and not in the past. Like in many cultural landscapes, such so-called progressive terraces are due to the interaction between plot boundaries and tillage but in north Ethiopia, the process is enhanced by soil conservation activities in farmland. The chapter starts with an investigation of the ard plough or mahrasha because this is the tool that does the soil translocation work.
... Within a decade, stone bunds could reduce the slope by 3% and in the first three years, the slope is reduced by 1% (Nyssen et al., 2019). This is due to the soils that are deposited in the stone bund treated land within a short period of time (Nyssen et al., 2019). ...
... Within a decade, stone bunds could reduce the slope by 3% and in the first three years, the slope is reduced by 1% (Nyssen et al., 2019). This is due to the soils that are deposited in the stone bund treated land within a short period of time (Nyssen et al., 2019). Gebrernichael et al. (2005) also indicated that significant amount of eroded soils get trapped in the newly stone bund treated lands. ...
... Similarly, Nyssen et al. (2008c) indicated that the average grain yields at the lower part of the stone bunds were higher than in the middle and upper parts by 53%. In addition, improvement in hydrological conditions and reduction of siltation risks on the water body were also exhibited as offsite benefits of Stone bunds (Nyssen et al., 2019). According to Damene et al. (2012), middle, upper and lower positions of the terrace had bulk density values of 1.60 g/cm 3 , 1.24 g/cm 3 , and 1.21 g/cm 3 , respectively. ...
Land degradation and impairment of ecosystem services (ES) have been a serious problem in Ethiopia, due to excessive pressure on and improper use of land and water resources. Thus, various land management (LM) practices have been implemented to enhance ecosystem service and environmental sustainability. However, very little is known about the influence of efficacious land management practices on multiple ecosystem service. This paper assesses the implication of land management practices on crop yield, soil carbon stock, soil fertility, soil moisture, runoff, soil loss, nutrient loss, and cultural/societal services. A systematic review and synthesis methods were employed. Accordingly, different search engines were used to search and access published articles. Then, predefined criteria were used to screen relevant articles, where 571 observations from 92 studies were extracted and synthesized. The results showed that agronomic practices were increased grain yields, soil carbon stock, soil fertility, and soil moisture on average by 27.6%, 29.47%, 43.36%, and 14.26%, respectively. Biological practices also regulated runoff, soil loss, and nutrient loss on average by 45.81%, 59.47%, and 93.55%, respectively. Overall, land management practices efficacious to enhance bundle ecosystem service delivery but soil bund and fanyaa juu reduced grain yields on average by 24.4% and 21.9%, respectively. This indicates that there are a trade-offs between provisioning and other services like regulating, supporting and cultural practices under physical structures. Furthermore, land management practices were used to deliver ecosystem service at different times, positions and spatial scales. The integration of properly designed physical structures with agronomic and biological practices is imperative to enhance ecosystem service and balance the trade-offs in the agricultural landscapes. Further, it is important to find out a combination of alternative agricultural land management practices and their impacts on bundle ecosystem services at different temporal and spatial scales. Résumé La dégradation des terres et la dégradation des services écosystémiques (SE) ont été un problème grave en Éthiopie, en raison d'une pression excessive et d'une mauvaise utilisation des terres et des ressources en eau. Ainsi, diverses pratiques de gestion des terres (LM) ont été mises en oeuvre pour améliorer les services écosystémiques et la durabilité environnementale. Cependant, on sait très peu de choses sur l'influence des pratiques efficaces de gestion des terres sur les multiples services écosystémiques. Cet article évalue l'implication des pratiques de gestion des terres sur le rendement des cultures, le stock de carbone du sol, la fertilité du sol, l'humidité du sol, le ruissellement, la perte de sol, la perte de nutriments et les services culturels/sociétaux. Une 640 Biratu et al., 2021 revue systématique et des méthodes de synthèse ont été employées. En conséquence, différents moteurs de recherche ont été utilisés pour rechercher et accéder aux articles publiés. Ensuite, des critères prédéfinis ont été utilisés pour filtrer les articles pertinents, où 571 observations de 92 études ont été extraites et synthétisées. Les résultats ont montré que les pratiques agronomiques augmentaient les rendements en grains, le stock de carbone du sol, la fertilité du sol et l'humidité du sol en moyenne de 27,6 %, 29,47 %, 43,36 % et 14,26 %, respectivement. Les pratiques biologiques ont également régulé le ruissellement, la perte de sol et la perte de nutriments en moyenne de 45,81 %, 59,47 % et 93,55 %, respectivement. Dans l'ensemble, les pratiques de gestion des terres sont efficaces pour améliorer la fourniture de services écosystémiques groupés, mais la digue du sol et le fanyaa juu ont réduit les rendements céréaliers en moyenne de 24,4 % et 21,9 %, respectivement. Ceci indique qu'il existe un compromis entre l'approvisionnement et d'autres services tels que la régulation, le soutien et les pratiques culturelles dans les structures physiques. En outre, les pratiques de gestion des terres ont été utilisées pour fournir des services écosystémiques à différents moments, positions et échelles spatiales. L'intégration de structures physiques correctement conçues avec des pratiques agronomiques et biologiques est impérative pour améliorer les services écosystémiques et équilibrer les compromis dans les paysages agricoles. En outre, il est important de découvrir une combinaison de pratiques alternatives de gestion des terres agricoles et leurs impacts sur les services écosystémiques groupés à différentes échelles temporelles et spatiales.
... The essence of physical structures trap velocity and control the amount of surface runoff and associated soil and nutrients losses in the farm, as well as improving soil fertility and reducing soil erosion (Desta et al., 2005;Haile et al., 2006;Morgan, 2005). Nevertheless, the loss of cultivable area, waterlogging, pests, inconvenience for oxen plows, and soil disturbance are the associated problems (Adimassu et al., 2016;Nyssen et al., 2019) that reduce crop yields on average by 30-25% ( Figure 3). This indicates that tradeoffs exist between grain yields and other ES. ...
... Within a decade, stone bunds could reduce the slope by 3% and in the first three years, the slope is reduced by 1% (Nyssen et al., 2019). Mukai et al. (2020) also indicated that soil and stone bunds were reduced field slope by 0.16-0.28% ...
... Mukai et al. (2020) also indicated that soil and stone bunds were reduced field slope by 0.16-0.28% annually.This is due to the soils that are deposited in the soil and stone bund treated land within a short period of time (Mukai et al., 2020;Nyssen et al., 2019). Gebremichael et al. (2005) also indicated that significant amount of eroded soils get trapped in the newly stone bund treated lands and tillage-associated erosion was not increased along the time. ...
... The essence of physical structures trap velocity and control the amount of surface runoff and associated soil and nutrients losses in the farm, as well as improving soil fertility and reducing soil erosion (Desta et al., 2005;Haile et al., 2006;Morgan, 2005). Nevertheless, the loss of cultivable area, waterlogging, pests, inconvenience for oxen plows, and soil disturbance are the associated problems (Adimassu et al., 2016;Nyssen et al., 2019) that reduce crop yields on average by 30-25% ( Figure 3). This indicates that tradeoffs exist between grain yields and other ES. ...
... Within a decade, stone bunds could reduce the slope by 3% and in the first three years, the slope is reduced by 1% (Nyssen et al., 2019). Mukai et al. (2020) also indicated that soil and stone bunds were reduced field slope by 0.16-0.28% ...
... Mukai et al. (2020) also indicated that soil and stone bunds were reduced field slope by 0.16-0.28% annually.This is due to the soils that are deposited in the soil and stone bund treated land within a short period of time (Mukai et al., 2020;Nyssen et al., 2019). Gebremichael et al. (2005) also indicated that significant amount of eroded soils get trapped in the newly stone bund treated lands and tillage-associated erosion was not increased along the time. ...
Human-induced land degradation and impairment of ecosystem services (ES) are among the serious problems in Ethiopia due to excessive pressure on land and water resources. Thus, various land management (LM) practices have been done to enhance ES and environmental sustainability. However, very little is known about the influence of efficacious LM practices on multiple ES. This study aims at assessing the implication of LM practices on crop yield, soil carbon stock, soil fertility, soil moisture, runoff, soil loss, nutrient loss, and cultural/societal services. A systematic review and synthesis methods were employed. Predefined criteria were 2 used to screen relevant articles; thereby, 572 observations from 94 studies were extracted and synthesized. The results showed that agronomic practices increased grain yields, soil carbon stock, soil fertility, and soil moisture on average by 28, 29, 43 and 14%, respectively. Biological practices regulated runoff, soil loss, and nutrient loss on average by 46, 59 and 94%, respectively. Overall, LM practices were efficacious to enhance delivery of ES bundles but soil bund and fanyaa juu reduced the grain yield on average by 24 and 22%, respectively. This indicates that there is a trade-offs between provisioning and other services like regulating, supporting and cultural under physical structures. However, landscape level collective impact of different LM practices exhibited without any ES trade-offs. The integration of properly designed physical structures with agronomic and biological practices is imperative to enhance ES and balance the trade-offs in the agricultural landscapes. Further, it is important to find out alternative combinations of agricultural LM practices and evaluate for ES delivery.
... Shallow, stony loam soils with moderate fertility (Eutric Regosol and Cambisol) (21) Deep, dark cracking clays with good fertility, but problems of waterlogging (Chromic and Pellic Vertisol) (12) Brown to dark, silty clay loams to loamy sands developed on alluvium, with good natural fertility (Fluvisol) (30) ...
... [19] [20] As a response to the strong degradation and thanks to the hard labour of many people in the villages, soil conservation has been carried out on a large scale since the 1980s and especially 1980s; this has curbed rates of soil loss. [21] [22] Measures include the construction of infiltration trenches, stone bunds, [23] check dams, [24] small reservoirs such as Chini and May Leiba as well as a major biological measure: exclosures in order to allow forest regeneration. [25] On the other hand, it remains difficult to convince farmers to carry out measures within the farmland (in situ soil management), such as bed and furrows or zero grazing, as there is a fear for loss of income from the land. ...
... cracking clays with very good natural fertility, waterlogged during the wet season (Chromic Vertisol, Pellic Vertisol)(12) brown loamy sands developed on alluvium along Giba River (Fluvisol) (30)This land system occurs on in the deeply incised gorge of Giba River, at the lower side of tabias Walta, Inda Sillasie, Amanit and Debre Nazret.Typical catena on the Adigrat Sandstone cliff and footslope in and near Avergele Lithic Leptosols around Dabba Selama monastery Alluvial plain of Giba River Typical catena in the alluvial plain of Giba River at the edge of Abergele At Kemishana, the Giba River leaves its gorge and enters in the alluvial plain Strongly incised Giba gorge stony, dark, loamy soils on calcaric material (Rendzic Leptosol) (3)shallow, stony to sandy loam soils on calcaric material (Calcaric Regosol and Cambisol)(21) brown loamy sands developed on alluvium along Giba River (Fluvisol)This land system occurs on Antalo Limestone, it is predominant in tabias Walta, Inda Sillasie, Ayninbirkekin, Amanit and Debre Nazret. ...
Summary of research findings, published on Wikipedia.
Similar Wikipedia pages are available for six other districts:
https://en.wikipedia.org/wiki/Category:Soil_geography_of_Tigray_(Ethiopia)
... The non-reverting animal-drawn plough (ard plough or mahrasha, as it is locally known) is the farm implement most widely used in Tigray (Nyssen et al., 2019b). The mahrasha is well integrated into the farming system, in view of its relative simplicity and regenerative character, its long-term traditional use and simple support systems (Solomon Gebregziabher et al., 2006). ...
... Multiple tillage operations are carried out to prepare a fine seedbed, particularly for tef with three to five operations, three for barley and two for pulses. However, upon lacking oxen or manpower, farmers may try to reduce the number of tillage operations, eventhough frequent tillage is required for heavy clay soils, which are widespread in the region (Alemtsehay Tsegay et al., 2019;Nyssen et al., 2019b). Farmers start ploughing before, and during the first rains. ...
Since November 2020, a civil war is taking place in Tigray (north Ethiopia), where about 75% of the active population are farmers. Here, we present the state of ploughing in Tigray’s war conditions, early in the 2021 rainy season and discuss contextual factors. Early May 2021, around Mekelle, very few croplands have been ploughed, as compared to the situation in previous years, verified on historical Google Earth imagery, even though the 2021 spring rains correspond to average rainfall conditions in most of Tigray. The analysis of True Colour Composite images, produced from Sentinel satellite imagery pertaining to March-May 2021, shows that, unlike plantation farms, the eleven sampled irrigation schemes with smallholder farming are all operational, with an overall increase in irrigated land by 6% as compared to 2019-2020. A partial shift from commercial crops to cereals has taken place, which requires less human presence on the fields, hence less risk for the famers to encounter soldiers and get killed. The same processed Sentinel imagery shows very poor tillage on nine sample areas with rainfed farming in western and NW Tigray (scenes of approx. 6 km x 4 km), but relatively good ploughing progress in the rest of the region with often more land ploughed than in 2020, despite less rainfall in spring. The situation in western Tigray is particular, as there has been ethnic cleansing of the population and often the 2020 rainfed crops even have not been harvested. Many lands have remained unploughed, and irrigation along the Tekeze River has been abandoned. Overall in Tigray, war conditions have made ploughing very challenging. Oxen have been looted and deliberately killed, and farm inputs and farm tools have been destroyed by Ethiopian and Eritrean soldiers. Furthermore, farmers who want to plough feel vulnerable out in the open; in many places, Eritrean soldiers forbid the Tigrayan farmers to plough. While trying to produce, in any case, the Tigrayan farmers evaluate all risks involved with ploughing and organise lookouts verifying that no soldiers are approaching. However, there is still hope that a large part of the land will be sown timely, in difficult conditions, with crops that require minimal management, and without fertiliser, as the Tigrayan smallholder farming system, and farmer-led irrigation schemes are resilient, thanks to the remarkable ability of self-organisation by the local farming communities.
... In Tigray's longstanding indigenous smallholder farming system (D'Andrea 2008; Blond et al. 2018;Alemtsehay Tsegay et al. 2019), the average start of the around 100-days long growing period is June in most of the region (De Pauw and Ramasamy 2017). Land preparation, using a non-reverting oxen-drawn plough (Solomon Gebregziabher et al. 2006) is commonly used to prepare weed-free seedbeds and to enhance infiltrationmost crops entirely depend on rainfall without supplemental irrigation (Alemtsehay Tsegay et al. 2019;Nyssen et al. 2019b). Tillage needs to be done within the months of April to June, preceding the main growing season (Tewodros Gebreegziabher et al. 2009). ...
During the 2021 conflict in Tigray (north Ethiopia) crop cultivation has been hampered by warfare. Oxen have been looted and killed, farm inputs and tools destroyed by Ethiopian and Eritrean soldiers. Farmers felt vulnerable out in the open with their oxen. To produce, farmers evaluated risks involved with ploughing and organised lookouts. Overall, a large part of the land had been tilled in difficult conditions, and crops sown that require minimal management, without fertiliser, what led to low yields. True Colour Composite images, produced from Sentinel satellite imagery show that smallholder irrigation schemes were operational. There was a shift from commercial crops to cereals. The situation in western Tigray was particular, as there has been ethnic cleansing of the population and often the 2020 rainfed crops had even not been harvested. Overall, our findings show that the Tigrayan smallholder farming system is resilient, thanks to community self-organisation, combining common strategies of agrarian societies in wartime: spatio-temporal shift in agricultural activities to avoid the proximity with soldiers and shifts in crop types. Rather unique is the relying on communal aid, while the blockade of the Tigray region made that outmigration and off-farm income were no options for the farmers.
... Alternatively, terraces may form above stone bunds, soil bunds, Fanya juu or hedgerows, following erosion below the barrier and accumulation of sediment above the adjacent barrier further downslope. The reduction of the steepness of slopes (Nyssen et al., 2019;Subhatu et al., 2018) helps limiting the generation of surface runoff and soil erosion in response to rainfall. ...
Erosion and associated soil degradation are major threats to cropland productivity on the steep slopes of the Ethiopian highlands. To limit erosion from cultivated land on sloping terrain, stone bunds for soil conservation have been used for decades, resulting in the formation of terraces. Although qualitatively well known, the difference in soil properties and crop performance between the upper and lower sections of the terraces (intra-bund areas) have not been documented quantitatively. Here, we assess differences in soil properties of the plow layer and crop performance in the upper and lower sections of terraces in between stone bunds in southwest Ethiopia. A total of 27 terraces, with a length of 28.5 to 57 m and a distance of 6.5–14.7 m in between adjacent stone bunds, were sampled on six different farms during the 2018 and 2019 cropping seasons. The difference in soil properties were analyzed using analysis of variance (ANOVA). Results showed that, in the lower section of a terrace, the concentration of soil organic carbon (18.6 g kg⁻¹), total soil nitrogen (2.1 g kg⁻¹) and exchangeable potassium (328 mg kg⁻¹) were significantly greater (p<0.01) than in the upper section. Also, grain yield and biomass of maize, teff, broad bean and sorghum were significantly greater (p<0.05) in the lower section. This was particularly true for maize for which the yield in 2018 increased from 0.7 t ha⁻¹ in the upper sections to 2.6 t ha⁻¹ in the lower sections. Optimizing crop yields on terraces requires adaptive fertilizer application and crop choice.
Smallholder, rain-fed agriculture has been practiced in Tigray, Ethiopia for thousands of years, so farmers have experience with natural disturbances. However, civil war began in November 2020 and disrupted the agricultural system through theft and destruction of farming implements, livestock, and crops, and threats towards human activity, impacting farmers’ ability to work their land. To investigate effects on agricultural activity we used remote sensing data and machine learning methods to map cropped area across Tigray from 2017-2022. Specifically, spectral mixture analysis was applied to Sentinel-2 data to produce green vegetation, non-photosynthetic vegetation, soil, and shade endmember fractions. Monthly medians of these fractions, along with reference data generated by manual interpretation of very high spatial resolution data, were used to drive random forests-based classifications of crop/no-crop for each year. Initially we used a greenness threshold to distinguish between active and abandoned fields for a given year, but when rainfall is adequate, fields abandoned due to conflict can green up with weeds rather than crops, leading to false positive crop detections. In the spring, abandoned fields have a bright soil crust due to a lack of plowing, so these fields were removed from the crop reference data if the March soil endmember fraction anomaly was greater than 0.15. Overall accuracies of the crop/no-crop maps ranged from 80-90% for the different districts. Producer’s/user’s accuracies for the crop class ranged from 55-80%/69-90%. In 2021, crop area declined by 29% and 20% in West and Northwest Tigray, respectively, corresponding with reports of intense conflict there. The rest of Tigray showed a mix of smaller increases and decreases, indicating more resilience to the regional conflict. Finally, in 2022 we found increases in cropped area relative to 2021, for all districts except West Tigray, indicating recovery except for the areas where conflict was most severe.
Human-induced land degradation and impairment of ecosystem services (ES) are among the serious problems in Ethiopia due to excessive pressure on land and water resources. Thus, various land management (LM) practices have been done to enhance ES and environmental sustainability. However, very little is known about the influence of efficacious LM practices on multiple ES. This study aims at assessing the implication of LM practices on crop yield, soil carbon stock, soil fertility, soil moisture, runoff, soil loss, nutrient loss, and cultural/societal services. A systematic review and synthesis methods were employed. Predefined criteria were used to screen relevant articles; thereby, 572 observations from 94 studies were extracted and synthesized. The results showed that agronomic practices increased grain yields, soil carbon stock, soil fertility, and soil moisture on average by 28, 29, 43 and 14%, respectively. Biological practices regulated runoff, soil loss, and nutrient loss on average by 46, 59 and 94%, respectively. Overall, LM practices were efficacious to enhance delivery of ES bundles but soil bund and fanyaa juu reduced the grain yield on average by 24 and 22%, respectively. This indicates that there is a trade-offs between provisioning and other services like regulating, supporting and cultural under physical structures. However, landscape level collective impact of different LM practices exhibited without any ES trade-offs. The integration of properly designed physical structures with agronomic and biological practices is imperative to enhance ES and balance the trade-offs in the agricultural landscapes. Further, it is important to find out alternative combinations of agricultural LM practices and evaluate for ES delivery.
Traditionally, livelihood security among smallholder farmers in Ethiopia is strongly dependent on rainfed agriculture, with which over 95% of the food is produced. Conventional soil cultivation practices, such as excessive tillage, overgrazing, and complete removal of crop residues at harvest leave the soil unprotected, and therefore trigger land degradation. Practicing conservation agriculture (CA) can help to minimize land degradation, i.e., soil erosion, soil fertility decline, and hydrological challenges, through simultaneously practicing ac-tivities such as minimal soil disturbance, crop residue retention, and crop rotation. In addition, CA can help to improve the livelihoods of smallholder farmers while promoting better soil carbon sequestra-tion. Generally, uptake of CA by smallholder farmers is persistently low in Ethiopia due to low degrees of mechanization, a lack of soil fertility management options, and competition for crop residues with other end uses. In turn, smallholder farming communities of the drylands have developed skills and experiences of in situ soil and water conservation, such as contour plowing and furrow and raised beds systems, which can be integrated with CA for improved productivity and profitability. To facilitate wider adoption of CA by smallholder farmers in Ethiopia, tailoring the management schemes is crucial to fit the existing diversity of agroecological and socioeco-nomic farm settings.
This book is based on over 150 papers about the Dogu’a Tembien district in Ethiopia. To reach a broader public of people interested in geosites and human-environment interactions, the authors here add a geoguide about this mountain district in Ethiopia(13°30’ N, 39°10’ E; upto 2850 m high) which shows a varied lithology.
A large team has carried out research in that district over the past 23 years, including long stays in the areas. Numerous viewpoints and geosites are only accessible on foot; hence the authors prepared the book as a trekking guide, which will enhance sustainable tourism in the same time. This edited work summarises the study results in the international literature into a comprehensive book, which comprises 35 thematic chapters, detailed description of 573 km of trekking routes to access the landscape and the most scenic excursion points, as well as the necessary logistical information. A state-of-the-art trekking map is included as a digital annex.
https://www.springer.com/gp/book/9783030049546
Between the cultivated fields in the highlands of Tigray, one finds, besides the recently introduced stone bunds, many lynchets, with a height ranging from 0·3–3 m. Grasses occupy the riser and a more or less large strip on the shoulder.Traditionally, farmers established an untilled strip of about 2 m wide at the lower plot limit. This grass strip reduced runoff velocity, allowed for water to infiltrate and trapped sediment. Year after year, these lynchets, locally called dagat, continued to grow. In this study, the dagat technique is characterized and its evolution and reasons for partial destruction are outlined. Stereoscopic aerial photo analysis shows for the study area near Hagere Selam (13 °39′N, 39 °10′E, 2650 m a.s.l.) that 20·7 per cent of the major dagats (more than 1 metre high) have disappeared between 1974 and 1994. These lynchets, however, remain an important linear element in the landscape (22·7 m ha−1, i.e. their density on cultivated fields is much higher). Of the smaller lynchets, a great proportion has been levelled in order to increase plot surfaces and spread fertile soil over the field. Famines and impoverishment caused the farmers to increase short-term agricultural production in this way.Since the 1980s, the farmers built stone bunds on most of the cultivated land. Their average length equals 56·1 m ha−1 in the study area. The establishment of stone bunds results in the development of small terraces. Especially during recent years, there is a tendency to integrate the traditional knowledge of dagat with the building of stone bunds.A quantitative assessment of the effectiveness of both techniques must be made. Copyright © 2000 John Wiley & Sons, Ltd.
Gullies have been a common phenomenon in semi-arid northern Ethiopia for the last centuries. On the other hand, soil and water conservation (SWC) structures have been implemented since a long time to curb soil erosion. However, like most of the affected areas worldwide, density and distribution of gullies and SWC structures, their causes and interrelations are poorly understood. The aims of this study were to develop a technique for mapping these densities of gullies and SWC structures, to explain their spatial distribution and to analyze changes over the period 1935 – 2014. Aerial photographs from 1935-36 and Google Earth images from 2014 of the 5142 km2 Geba catchment were used. Transect lines were established to count gullies and SWC structures in order to calculate densities. On average, a gully density of 1.14 km km-2 was measured in 1935-36 of which the larger portion (75%) were vegetated, indicating they were not very active. Over 80 years, gully density has significantly increased to 1.59 km km-2 with less vegetation growing in their channel, but 66% of these gullies were treated with check dams. There were ca. 3 km km-2 of indigenous SWC structures (daget or lynchets) in 1935-36 whereas a high density (20 km km-2) of introduced SWC structures (mainly stone bunds and terraces) were observed in 2014. The density of gullies is positively correlated with slope gradient and shrubland cover and negatively with cropland cover, whereas the density of SWC structures significantly increased with increasing cropland cover. Density maps of gullies and SWC structures indicate sensitive areas to gully formation and priority areas for the implementation of soil and water conservation structures in Geba catchment. The obtained results illustrate the feasibility of the methods applied to map the density of gullies and SWC structures in mountainous areas.
Soil translocation due to tillage by the ox-drawn ard plough appears to be an important source of colluviation behind stone bunds and lynchets in the Ethiopian highlands. To quantify erosion rates caused by this plough in Ethiopia, painted and numbered rock fragments, 3–5cm in intermediate diameter, were used as tracers to monitor soil movement on 16 sites, each having a different slope gradient, in the district of Dogu’a Tembien, Tigray Region, Ethiopia. Average tillage depth was 8.1cm and the net mean downslope displacement distance per tillage operation ranged from 4.7cm for a 0.03mm−1 slope to 34.4cm for a field with a gradient of 0.48mm−1. There was a strong correlation (R2=0.84, P15cm intermediate diameter) are obstacles to the downslope movement of tilled soil. The unit soil transport rate (Qs) per tillage operation ranged from 4.8kgm−1 on the 0.03mm−1 slope to 38.7kgm−1 on the 0.48mm−1 slope. These values represent the mass of soil deposited by tillage behind 1m of lynchet or stone bund. During each tillage operation the same mass of soil is also removed from the foot of the upper stone bund or lynchet. For the first tillage operation, before the onset of the rainy season, the tillage transport coefficient (K) was 68kgm−1. As farmers till 1–4 times per year, annual K values can be assessed to range from 68 to 272kgm−1. These values are less than those observed for mechanised tillage, which however, is usually conducted on less steep slopes. On average, tillage erosion can be held responsible for half of the sediment deposited behind newly constructed stone bunds in the Tigray highlands.
Although the development of animal drawn tillage tools in the world has been on the agenda for thousands of years, there is still room for their improvement. The present study attempts to give an overview of previous works toward development of animal drawn tillage tools and to identify the areas having most potential for future improvement. The socio-economy, natural resource situation, historic perspective of animal traction in eastern and southern Africa and more specifically the ard plough history in Ethiopia are presented. The design, construction, performance and attempts done since 1939 for the improvement of the ard plough in Ethiopia are also presented. Moreover, trials towards the development of appropriate farm implements for Vertisols management, i.e. the broad bed maker (BBM) were also surveyed. From the review, it can be concluded that previous developments in animal traction tillage implements relied on cultural, trial and human experience. With the recent development in farm technologies and mathematical modelling techniques supported by computer-based simulations, new methodologies in research are available to improve animal traction tillage implements. When adopted, these methodologies could significantly assist in optimising the implement designs and operational conditions aiming at minimum draught requirement and best soil manipulation performance.
The aim of the research presented here was to analyse soil erosion in response to changes in agricultural and soil conservation practices throughout history. The Aksum area (Tigray, northern Ethiopia) presents favourable conditions for the development of a long-term approach for assessing soil conservation techniques that have been applied for centuries (i.e., since the Aksumite kingdom, 400 BC to 800 AD). These techniques have been maintained until the present day, and parts of the terraced systems of the area are still in use. During the 1970s, social and political events led to a remarkable change in land use patterns, and large arable areas were converted into grazing land, resulting in a significant increase in soil loss. The rates of soil erosion were evaluated based on analyses of the deep scratches (plough marks) left on stones in the soil by the maresha, the ard plough pulled by oxen used in agricultural practices of the area, and the patinas, varnishes and weathering rinds exposed by soil los
In most smallholder farms in Ethiopian highlands, farmers still use the wooden ard plough (Maresha). This study was undertaken to understand and optimise the traction forces provided by the draught animals. An ard plough equipped with three load cells (one on the beam and one on each side of the yoke) was implemented to measure traction forces required for tillage of four Vertisol fields under wet and dry conditions. Tillage was performed at three different depths of shallow (0–5 cm), medium-deep (5–10 cm) and deep (10–15 cm). The interpretation of force measurement was done for equally and unequally strong pair of oxen. After tillage, soil samples were taken for the determination of bulk density and moisture content. The cross-section area of furrow profile (CSAFP) and depth were also measured. With the measurement of equally strong oxen, each ox provided 50% of the total traction force required for tillage. However, with unequally strong oxen, different contributions of each ox to the total traction force were found. The stronger ox moved faster than the weaker ox, creating an asymmetric position of the yoke. In this situation, the weaker ox had to work harder to overcome the force transferred from the strong ox and correct the asymmetric position of the yoke. Thus, the weaker ox had to provide a larger force to the total traction force compared to the stronger ox. A larger traction force was measured with the yoke asymmetric position for smaller depth, speed and CSAFP. Therefore, farmers in the Ethiopian highlands can improve the tillage efficiency of the Ethiopian ard plough by using equally strong pairs of oxen. However, with unequally strong oxen the weaker ox should be enhanced to walk a head of the stronger ox, allowing the latter to provide the larger required traction force. # 2007 Elsevier B.V. All rights reserved.
Since two decades, stone bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone bunds is 58 t ha−1 year−1.The Universal Soil Loss Equation's P-factor for stone bunds was estimated at 0.32. Sediment accumulation rates increase with slope gradient and bund spacing, but decrease with bund age. Truncation of the soil profile at the lower side of the bund does not lead to an important soil fertility decrease, mainly because the dominant soil types in the study area (Regosols, Vertisols and Vertic Cambisols) do not have pronounced vertical fertility gradients. Excessive removal of small rock fragments from the soil surface during stone bund building may lead to a three-fold increase in sheet and rill erosion rates. Negative effects of runoff concentration or crop burial by sediment deposition due to bunds were only found over 60 m along 4 km of studied bunds. As the rodent problem is widespread and generally not specific to stone bunds, it calls for distinct interventions. On plots with stone bunds of different ages (between 3 and 21 years old), there is an average increase in grain yield of 53% in the lower part of the plot, as compared to the central and upper parts. Taking into account the space occupied by the bunds, stone bunds led in 2002 to a mean crop yield increase from 0.58 to 0.65 t ha−1. The cost of stone bund building averages €13.6 ha−1 year−1, which is nearly the same as the value of the induced crop yield increase in 2002 (€13.2 ha−1 year−1). Besides positive off-site effects such as runoff and flood regulation, the enhanced moisture storage in deep soil horizons on both sides of the bunds indicates that the stone bund areas can be made more productive through tree planting. We conclude that from the technical, ecological and economical point of view, the extensive use of stone bunds, involving people's participation, is a positive operation. Overall, 75% of the farmers are in favour of stone bund building on their land, which is a clear indication that the local community perceives this conservation measure as being beneficial.
The use of the marasha ard plough for conservation agriculture in Northern Ethiopia
Indigenous tillage systems are often undervalued in conservation agriculture (CA). In Ethiopia, since the 1970s there have been several attempts to develop and implement often major modifications to the marasha, the traditional ox-drawn ard plough, with the main aim of creating various types of surface depressions. The establishment of furrows and ridges increases soil moisture and grain yield and reduces soil loss. Dissemination of the modified tools, however, remains limited. Recent tendencies are towards testing relatively simple conservation agriculture tools. Major challenges remain, however; the need for capacity building and problems in marketing the tools. From experimental plots, often worked with exotic tools, there is a long road to real adoption by farmers. Rather than developing yet another CA tool, we investigate whether CA-based resource-conserving technologies might be achieved successfully with simple changes to the use of the marasha. On-farm observations on traditional conservation techniques were carried out throughout the northern Ethiopian highlands, and experiments were conducted involving resource-conserving technologies. Farmers traditionally use the marasha ard plough for various types of in situ soil and water conservation by creating surface depressions, either at the moment of sowing (terwah, derdero) or after crop emergence (shilshalo). Building upon this indigenous knowledge, we further developed resource-conserving technologies into a system named derdero+, whereby the traditional ard plough was found suitable for a “bed-and-furrow” system. From the socio-economic point of view, implementation of permanent beds and retention of stubble leads to decreased oxen (and straw) requirements, but also to an increased need for weeding in the first years. To overcome that problem, we introduced glyphosate herbicide into the tillage system. The decreased runoff (−51%) and soil loss (−81%) allow protection of the downslope areas from flooding, but soil nutrient build-up and soil structure improvement are slow processes, and hence the full benefit of the permanent bed system can only be expected after some years. Overall, this type of resource-conserving technology can be part of the ongoing intensification process which includes physical soil and water conservation, slope reforestation and irrigation development. It has, however, its own niche: the cropped land sensu stricto, i.e. the most important part of the land, both for the farmer and for a nation that is striving for long-term food security.
The antiquity of cultivation and herding in Ethiopia
- D Phillipson
Phillipson D (1993) The antiquity of cultivation and herding in Ethiopia. In: Shaw T, Sinclair
P, Andah B, Okpoko A, eds. The Archaeology of Africa: Food, Metals and Towns.
Routledge: 344-357
A mobile, in-situ testing device to investigate soil-maresha plough interaction
- Solomon Gebregziabher
Solomon Gebregziabher (2017) A mobile, in-situ testing device to investigate soil-maresha
plough interaction. PhD thesis, KULeuven, Belgium
Interdisciplinary on-site evaluation of stone bunds to control soil erosion on cropland in Northern Ethiopia
- J Nyssen
- J Poesen
- Desta Gebremichael
- K Vancampenhout
- Gebremedhin Yihdego
- G Govers
- H Leirs
- J Moeyersons
- J Naudts
- Nigussie Haregeweyn
- Jan Nyssen
In one tillage operation, weeding, thinning and root pruning is done; the furrows also decrease runoff and enhance infiltration
- Argaqa
Argaqa. In one tillage operation, weeding, thinning and root pruning is done; the furrows also
decrease runoff and enhance infiltration. After Nyssen et al. (2011)