Berken Maresha: a new plow for sustainable agriculture

by

Melesse Temesgen (PhD)

Aybar Engineering PLC, Addis Ababa, Ethiopia

Email: melesse_tem@yahoo.com

Summary

Farming in Ethiopia started several millennia ago. The traditional tillage implement in Ethiopia, called Maresha, has been used for a couple of thousands of years, particularly in the highlands. The plow has got several problems associated with its geometry. The plow causes high surface runoff and soil erosion by water. As a result, much of the highland in Ethiopia is severely degraded leading to decline in crop productivity. Other impacts of soil erosion include river pollution and siltation of reservoirs. Currently, Ethiopia is building several dams including the Great Ethiopian Renascence Dam. Sediment from farmland is expected to silt up the reservoirs.

Early attempts to replace the traditional tillage implement by the mouldboard plow failed because of high draft power requirement and other reasons whereas replacement of oxen by tractors has not been successful because of no benefit in crop productivity from using tractors in addition to other reasons. Over the last 20 years, attempts to introduce conservation agriculture could not be successful because of socio-economical, technical as well as environmental factors that make much of the Ethiopian highlands unique thus requiring a different type of tillage system. Recently, a new type of plow, called Berken Maresha, has been developed. Field test results have shown that the plow has got up to 14 advantages compared to the traditional tillage implement including reduced power requirement, increased rainfall infiltration and hence reduced surface runoff and soil erosion as well as increased crop yields.

Introduction

Traditional tillage system in Ethiopia mainly involves the Maresha plow (Figure 1a), which has been used for several millennia (Goe, 1987). The main problems of the Maresha plow are shallow penetration leading to hard pan formation (Biazin et al, 2011; Hussein et al, 2019) and the need for repeated cross plowing (Temesgen et al, 2008). The plow creates V-shaped furrows, which leave unplowed strips of land between passes i.e., furrows.  The V-shaped furrow is the result of the geometry of the Maresha (Temesgen et al, 2008). As a result, farmers have to plow the land repeatedly in order to loosen the unplowed strips of land. Since it is inconvenient to carry out consecutive tillage operations along the same direction, farmers have to practice cross plowing. During the second plowing, farmers run over the already plowed land approximately 50% of the time thereby wasting their time and energy. Even after cross plowing, spots of unplowed land remain with weeds intact. Farmers have to come again with the Maresha plow in order to disturb these spots during which the majority of the time and energy is wasted by running over the already plowed land. This is the main reason for repeated cross plowing and hence land degradation in Ethiopia. This article describes the problems associated with the traditional plow, Maresha, failures of past attempts to improve the situation and the development of the Berken plow together with field test results carried out by different institutions.

                        a                                              b                                              c

Figure 1 (a) The traditional plow in Ethiopia, Maresha, and plowing up & down the slope (b&c)

Problems associated with repeated cross plowing with the Maresha plow

1. Wastage of time and energy. More time and energy is wasted through repeated cross plowing because of running on already plowed fields.
2. Damage to the soil structure. Repeated plowing causes damage to the soil structure and loss of soil organic carbon.
3. Loss of soil and water. Cross plowing rules out contour plowing. Farmers are forced to orient their tillage direction along or nearly along the slope in one of any two consecutive plowing operations. In moderate to steep slopes (Figure 1b&c) plowing up and down the slope opens up water ways and encourages flow of water along the slope leading to high surface runoff and hence high soil erosion. Repeated cross plowing is the main cause of land degradation in Ethiopia.
4. Increased surface runoff has increased stream flows during the rainy season while reducing the same during the dry season. Due to reduced infiltration, groundwater levels are low. Reduced dry season stream flow and low level of ground water reduces water available for irrigation as well as the ecosystem during the dry season.
5. The combined effect of land degradation and shortage of water for dry season irrigation has led to a significant decline in agricultural productivity
6. Moreover, cross plowing causes changes in rake angle of the Maresha between plowing up and down the slope making it difficult for the farmers to maintain depth of plowing in addition to drudgery of walking up and down along steep slopes for both oxen and farmers.
7. Cross plowing makes it difficult to plow fields treated with soil conservation structures (soil bunds, etc). Farmers complain about difficulty in turning oxen when plowing perpendicular to bunds because (1) the distance that oxen and the farmer travel before turning is too short and hence too much time is wasted during turning makes the plowing operation inefficient and (2) the oxen and the farmer have to jump over the structures adding to the drudgery and causing damage to the bunds.
8. Poor distribution of water across the terrace. Plowing perpendicular to the bunds (Figure 2a) enhances flow of water from the upper part to the lower part of the terrace. In moderate to high rainfall areas this leads to stagnation of water on the lower side turning the crop yellowish (Figure 2b). In low rainfall areas the crop in the upper part of the terrace suffers from moisture stress.

                                    (a)                                                                    (b)

Figure 2. Plowing perpendicular to bunds (a) is not only inefficient and difficult to turn oxen but also results in poor distribution of rainwater across the terrace leading to yellowish and stunted growth at the lower side of the terrace (b) in wetter areas. The opposite occurs in dry areas.

Attempts to mechanize agriculture in Ethiopia

Promotion of tractors to mechanize farming operations has not been successful either. Tractors were introduced to Ethiopia nearly 6 decades ago. It was hoped that oxen would soon be replaced by tractors. Subsequent governments made relentless efforts to replace oxen by tractors. Due to several factors, however, the adoption of tractors among smallholder farmers has been very low.

A recent study by IFPRI involving 1800 smallholder farmers showed no crop productivity benefit from using tractors compared to oxen (Brehane et al, 2017). The author has also made personal communications with farmers in Gonder, East Shoa and Arsi regions in Ethiopia where all farmers confirmed that the yields they get from tractor plowing is less than that they get from oxen plowing. The reason why tractor plowing gives lower crop yields than oxen plowing has not been scientifically studied. So, the rationale  for using tractors for plowing instead of oxen is time saving. That means if a farmer can’t prepare seedbed timely, he or she has to use a tractor. This is true if the farmer has got a large holding or if he/she is growing crop more than once per year (irrigation, bimodal rainfall) provided single cropping (e.g. maize or wheat only) is practiced. Otherwise, studies have shown that when labor is abundant and land is small and fragmented, mechanization is not profitable (Binswanger, 1986). In Ethiopia, average land holding is estimated to be 0.5 ha, which can be easily managed without the need for tractors. Clustering of plots has got several advantages but as long as the land is owned by the same farmers replacing oxen by tractors would imply that farmers are going to stay idle while their fields is plowed by tractors, which is not economical. Replacing oxen by tractors requires that the clusters are owned by fewer farmers and the rest of the rural population is engaged in other jobs, which requires the further development of the industrial and service sectors. As more people are employed in the industrial and service sectors the percent of the population engaged in agriculture decreases to 2 to 3% as in the developed nations. At the moment, close to 80% of the population in Ethiopia is engaged in agriculture. The development of the industrial sector has reached a high level in the developed nation because they had the opportunity to export industrial products to developing countries. Ethiopia may not have the same level of opportunity. That means it will take longer for Ethiopia to reduce the percentage of the agrarian population to the same level as that of the developed nations thus challenging the agricultural mechanization process.

Another challenge to tractorization  is unique crops like tef and vertisols (black soils). In the highlands of Ethiopia there are about 7.6 million hectares of vertisols. Farmers plow muddy fields to plant tef, chickpea and other crops. The muddy fields are not suited to tractor plowing. Moreover, soil damage is high when it is plowed in such conditions.  

Land ownership policies also hinder the mechanization of agriculture, which necessitates land consolidation by few farmers. Allowing farmers to sell their land may enhance mechanization but its consequence can be disastrous unless there is a well developed industrial and service sector that can absorb the displaced labor. So, the government policies that do not allow farmers to sell their lands might be justified. But policy makers should also realize that large landholding is the key to tractorization and hence they should try to balance ambition with reality when trying to replace oxen by tractors.

In recent years, as part of the first phase of the growth and transformation program launched in Ethiopia, it was proposed to replace at least 50% of the draft animals (mainly oxen) by mechanical power, i.e., tractors, within 5 years.  That was too ambitious and not rational. In Ethiopia, there are about 15 million oxen used for plowing. A large four-wheel tractor can replace a maximum of 20 oxen. That means in order to replace 50% of the oxen or 7.5 million oxen, we need 375,000 high power four-wheel tractors, which can cost up to 20 Billion USD without considering the required implements (plows, planters, harrows, etc.), spare parts, fuel, etc. The country cannot afford so much capital in hard currency even if the above factors hindering tractorization are not in place.

Tractorization of small farms has always been the ambition of leaders in Africa. The ambition arises from the assumption that developed nations are rich because they use tractors for plowing. In reality, the reverse is true i.e., the developed nations use tractors because they are rich. Rich means large landholding, which implies commercial farming as opposed to subsistence. So, despite relentless efforts to tractorize smallholder farming in Africa, the outcomes have always been disappointing. A study by Groote et al, (2018) showed that farmers in neighboring Kenya are increasingly using oxen for tillage, rising from 17% to 33%, accompanied by a declining trend in the use of tractors, from 5% to 2%, during the period 1992 to 2012.  Teferea (2011) listed a number of advantages of draft animal power over tractors for most farms in Ethiopia.

Others argue that two-wheel tractors can be appropriate for smallholder farmers in Ethiopia. That is not true. A closer examination of the traction power development of these tractors reveals that the two-wheel tractors cannot produce the required force to pull plows. Moreover, these tractors come with rotovators, which get powered directly from the engine and rotate at a speed of 540 revolutions per minute. The rotovators plow the soil by cutting and throwing it backwards and upwards at a very high-speed pounding with iron sheet roof, similar to a hammer mill, thereby causing excessive pulverization. Such type of tillage can only be sustainable in the cultivation of rice paddy fields and in temperate soils. Rice paddy fields remain saturated during cultivation such that the water protects the soil from damage. In temperate regions, the cold climate slows down carbon oxidation in addition to the already high organic matter content of the soil in those parts of the world.  In the upland farming systems of Ethiopia, however, rototvators will damage the soil through loss of soil organic carbon leading to a further land degradation. Moreover, since the rotovators cultivate at a shallow depth, the water holding capacity of the soil is heavily reduced leading to increased surface runoff and soil erosion.

Apart from damaging the soil, the capacity (work rate) of the two-wheel tractors is not better than a pair of oxen. Tests conducted at Melkassa Agricultural Research Center showed that a 6.5hp two-wheel tractor requires 30 hours to plow one hectare while a 15hp tractor takes 20 hours (Laike Kebede and Bisrat Getenet, 2017). A pair of oxen would take about 24 hours to finish one hectare. So, basically there is no significant difference between the work rates of a pair of oxen and two-wheel tractors thus making hiring services of the two-wheel tractors unprofitable. In contrast, large four-wheel tractors can plow a hectare of land in as short as 2.5 hours. That means hiring services with large tractors can be profitable. Repair and maintenance costs are not very different, which means that those owning large tractors will have an advantage in terms of economies of scale. So, in the limited areas where farmers can’t finish land preparation within the season it would be advisable to hire larger four-wheel tractors at least for primary tillage. In the majority of the cases, however, farmers would have sufficient time to plow their fields and hence availing improved animal drawn plows that can improve the work rate of oxen would be feasible.

This implies that smallholder farmers in Ethiopia who have had a long history of using oxen for plowing may not be expected to fully adopt tractors in the near future.  Draft animal power is considered friendlier to the environment (Dikshit and Birthal, 2010). Therefore, improving and promoting animal drawn tillage implements that can be easily adopted by smallholder farmers need to be considered with the aim of conserving soil, water and energy while improving crop yields.

Animal drawn moldboard plows and rippers

The first improved plow introduced to Ethiopia is the mould board plow. Several institutions have tried to introduce different types of mouldboard plows. The main problem with the mouldboard plows has been the high draft power requirement.  Farmers rejected the different types of mouldboard plows mainly because of high draft power requirements. The cost of production of the mouldboard plow is much higher than that of the traditional Maresha. When the mouldboard plow is used in moderate to steep slopes, turning the soil upwards requires much higher draft power. On the other hand, when the soil is turned downwards the soil is moved down along the slope, which is termed as tillage erosion. Farmers also complain about the need to move around the field as opposed to back and forth plowing with the traditional plow, Maresha. In addition, complete plowing with the moldboard plow resulting in smooth furrow bottom weakens the soil making it vulnerable to rill formation and accelerated surface runoff and hence higher soil erosion.

 In other African countries animal drawn mouldboard plows were introduced during the colonial era. The plow was introduced in conjunction with the use of oxen for draft power. However, research has shown that the smearing action of the mouldboard plow has caused formation of plow pans, which restrict infiltration and root growth, much quicker than the Maresha.

Rippers were proposed to disrupt the plow pans. However, conservation tillage systems promoted using rippers did not address the issue of weeds between ripped lines. Moreover, ripping along planting lines while leaving the land in between uncultivated reduced the water holding capacity of the soil especially in fields with long history of cultivation and hence compacted soils with poor infiltration rates. 

Conflicts between agronomists and conservationists

It is not uncommon to find smallholder farmers confused by the contradictory advices they get from agronomists and conservationists. Agronomists advise farmers to carry out repeated tillage to come up with weed free fine seedbed for improved grain yields. On the other hand, conservationists argue that repeated tillage damages the soil and hence tillage has to be reduced. In reality, farmers would have liked to reduce tillage in order to save time and energy. But through years of experimentation they have set the optimum number of tillage depending on soil type, crop type and rainfall onset as well as distribution. They may not notice the long term impact of repeated tillage on soil health. So, it is hard to convince them to give up short term benefits. However, the new concept of stepped tillage using Berken Maresha resolves the conflict by enabling farmers to undertake reduced number tillage with the added benefits of direct and indirect conservation of soil and water while increasing crop yields.

Conservation agriculture

Over the last 2 decades attempts have also been made to introduce conservation agriculture (CA). However, adoption of CA was hindered by the need for herbicide application, which has not been accepted by policy makers who favored labor intensive technologies in addition to the recent concerns raised after Glyphosate, the non selective herbicide used to replace plowing for the purpose of weed control, was declared ‘probable carcinogenic to humans’ by WHO. CA could not either be adopted because of insufficient mulch material in the crop-livestock mixed smallholder farming system where crop residues are needed for animal feed during the dry season. Moreover, farmers pointed out that they want to warm up the soil for better seed germination. This is so mainly in the highlands where the soil temperature is cooler than, for example,  the low lands of Benishangul and Gambella, which are found in the western parts of Ethiopia and where direct planting with a hoe is practiced traditionally. No till and soil cover reduced soil temperature for improved seed viability, which is one of the reasons for the adoption of the practice in hotter climates (Giller et al, 2015). Research has also shown that soils that are already low in soil organic carbon and compacted because of many years of cultivation need to be opened to allow infiltration (Aina et al., 1991; Chen et al., 1998; Steiner, 1998; Rockström and Jonsson, 1999; Biamah and Rockström, 2000; Freitas, 2000; Hoogmoed et al., 2004; Guto et al., 2011; Baudron et al., 2012; Sime et al. 2015).

The global distribution of CA (Table 1) shows that CA cannot be uniformly adopted in all countries as it can be seen in the table that close to 90% of the land under CA is found in South America, North America and Australia (Kassam et al, 2015).  One of the reasons for the adoption of CA in those countries is reduction of loss of soil organic carbon, caused by plowing with tractors at high speeds and at high soil temperatures, thereby maintaining soil quality (Giller et al, 2015). However, land degradation in the Ethiopian highlands comes mainly from soil erosion by water, through repeated cross plowing with Maresha (Temesgen et al, 2012) than from loss of soil organic carbon, which is largely caused by excessive soil pulverization through tractor plowing in hotter climates.

Table 1. Global distribution of CA in 2013 (Source: Kassam et al, 2015)

Giller et al. (2015) stated that the focus of CA is too restricted to address the technology needs for sustainable intensification. The authors proposed that a more flexible approach is needed to harness the benefits of “strategic tillage” to overcome major problems associated with continuous no-till, such as soil compaction. Therefore, there has to be a different type of CA until at least conditions allow to practice CA the way it is being practiced by the south Americans. So, we developed a new type of tillage system and a tool for a locally adapted conservation agriculture with the objectives of achieving sustainable agriculture through soil, water and energy conservation while at the same time increasing crop yields.

Berken Maresha: A new tool for sustainable agriculture

A new type of plow that addresses the concerns of both agronomists and conservationists has been developed by Aybar Engineering PLC. The plow has been successfully tested by different institutes in Ethiopia. The concept of the new tillage system is ‘stepped tillage’. Stepped tillage is a means of breaking the hard pan along a certain line accompanied by shallow tillage on both sides of the ripped line. This practice makes it possible to undertake ripping and shallow cultivation in one go. A new tillage implement called Berken Maresha (Figure 3) has been developed to accomplish stepped tillage. Berken in Amharic means ‘at different levels’.

The idea of stepped tillage was proposed by the author in 2007 following less-than-expected outcomes of field evaluations of a conservation tillage system that involved ripping along planting lines (Temesgen, 2007). Deeper tillage at the center is meant to disrupt the plow pan thereby increasing infiltration and root growth while the shallow cutting is meant to control weeds and to loosen the surface for increased infiltration. Initial field tests showed promising results whereby the plow pan was effectively disrupted leading to increased infiltration while reducing the number of tillage and increasing crop yields (Temesgen et al, 2012). However, the plow required too much draft power that it could not be adopted by farmers. Subsequent improvements were made with the 5th version  Arashogel (Nicol et al, 2015)  followed by the 6th version, Berken Maresha (Figure 3a), which was developed in 2015.  The new plow was commercialized in 2017.

Figure 3(b) shows the soil profile before and after a single plowing with Maresha and Berken Maresha. At the top of Figure 3(b) we see unplowed strips of land left by the traditional plow between each of the consecutive furrows as can be seen from the overlapping segments of before and after profiles. Farmers have to carry out tillage to plow these undisturbed strips of land. Through repeated cross plowing the soil becomes excessively pulverized making it vulnerable to rill formation in addition to damaging the soil structure. On the other hand, the soil profile resulting from the use of Berken Maresha (Figure 3b, bottom) shows that the field is completely disturbed in the first tillage, as evidenced by separated lines of before and after soil profiles, thereby making it unnecessary to carry out repeated tillage.  Moreover, the profile created by Berken Maresha consists of rugged furrow bottoms that act as invisible barriers (Siwur erken in Amharic) to the flow of water along the slope (Figure 3b and Figure 4). Figure 4 shows a photograph displaying the invisible barriers. The picture was taken after manually removing the loose soil plowed by Berken Maresha. The invisible barriers resist surface runoff and reel formation while allowing more infiltration and hence reducing soil erosion. The double edged advantage of the invisible barriers is that leaving these parts of the land undisturbed saves time and energy while conserving soil and water. In other words,. the smartness of the stepped tillage concept is that by saving time and energy that would have been spent on plowing parts of the land, leaving those parts undisturbed led to the construction of invisible soil and water conservation structures.

                        (a)                                                                                (b)

Figure 3 (a) Berken Maresha and (b) field profiles before and after tillage using Maresha (top) and Berken Maresha (bottom).

Figure 4. The invisible barriers (siwur erken) exposed by cleaning (removing the loose soil) after Berken plowing. The invisible barriers are laid along the contour thereby retarding down-slope flow of water and rill formation.

Advantages of Berken Maresha over the traditional Maresha

The concept of stepped tillage that avoided cross plowing and that resulted in plow pan disruption and non inverting tillage has got the following advantages

1. It requires less draft power
2. It remains stable in the soil and hence it requires less effort to maintain depth of operation thereby reducing drudgery to farmers. It makes it easier for women to operate the plow.
3. It reduces the number of plowing
4. It allows farmers to practice contour plowing, which among others, keeps the angle of penetration of the plow uniform throughout the operation as opposed to the traditional cross plowing, which            creates a high variation when plowing up and down the slope. Moreover, it reduces drudgery to both the oxen and the operator by avoiding walking up and down the slope
5. It reduces surface runoff thereby allowing more infiltration and increasing soil moisture
6. It reduces soil erosion
7. It increases groundwater recharge thereby improving dry season flow and ground water levels and hence making more water available for dry season irrigation
8. It reduces soil evaporation thereby improving soil moisture in dry areas
9. It penetrates deeper thereby breaking plow pan, allowing more infiltration and deeper root growth
10. It reduces weed population
11. It makes plowing in terraced fields convenient and increases the performance and life span of soil conservation structures
12. It increases grain yield
13. It reduces deforestation
14. It reduces clod formation

Results of field test on Berken Maresha

Different organizations have evaluated Berken Maresha and its predecessor, Arashogel, in comparison with the Maresha plow. Muche et al (2017)  showed that Berken Maresha penetrated to a maximum depth of 27.5cm while the traditional Maresha penetrated to a maximum depth of 18.1cm showing the potential for plow pan disruption by Berken Maresha. They also reported increased infiltration rates (46%) and root growth (40%) more than the traditional Maresha as well as more than 50% reduction in surface runoff and soil erosion.

Field experimentation conducted in central Ethiopia  (Laike Kebede et al, unpublished data, +251911771891, Melkassa Agricultural Research Center) showed that surface runoff and soil erosion are significantly reduced by Berken Maresha compared to the traditional Maresha (Table 2 (a) and (b)).

Table 2 (a). Effect of use of Berken Maresha on surface runoff and soil erosion. 

Source: Laike Kebede, unpublished data

Table 2(b) Comparison of minimum tillage with Berken Maresha (MT) and conventional Tillage with Maresha (CT) on soil loss

Source: Laike Kebede, Unpublished data

Results reported by Muche et al (2017) on surface runoff and soil loss (Table 3) are similar. They  compared Berken Maresha  (BT) with no tillage (NT), conventional tillage (CT) and deep tillage (DT). Deep tillage was carried out by manually digging the soil to a depth of 60cm, which may not be practical under small holder famers’ situation. Hence, it can be seen that Berken Tillage is the best option to reduce surface runoff by maximizing infiltration rates while at the same time giving the best yields and reducing soil loss. As usual, in soils with low organic matter content like most fields in Ethiopia (except in some locations of Benishangul, Gambella and parts of Southern Region) research has shown that NT reduces crop yields significantly (Aina et al., 1991; Chen et al., 1998; Steiner, 1998; Rockström and Jonsson, 1999; Biamah and Rockström, 2000; Freitas, 2000; Hoogmoed et al., 2004; Guto et al., 2011; Baudron et al., 2012; Sime et al. 2015) because in already compacted and prone to compaction soils, leaving the soil unplowed results in higher surface runoff and soil erosion in addition to increased weed infestation.

The implications of reduced soil erosion goes beyond reducing land degradation, which is meant for sustainable agriculture. Its environmental impact includes reduction of river pollution and reservoir siltation. Prior to the construction of the dams, the main concern, when it comes to soil erosion, was loss of soil fertility affecting productivity of upstream farmers. The impact of the sediment was felt by the downstream countries such as Sudan who spend millions of dollars every year trying to remove sediment from irrigation canals and reservoirs. With the construction of the dams inside Ethiopia, however, the effect of soil erosion will be double edged on Ethiopia. The Ethiopian government is at the moment campaigning on tree plantations one of the aims of which is reduction of soil erosion to minimize siltation of dams. The trees will contribute immensely but sediment coming from cultivated lands need to be reduced. Berken Maresha can make a significant contribution if it is made available to smallholder farmers who are at the moment using the traditional plow, Maresha.

Table 3. Field test results comparing No tillage (NT), Conventional Tillage (CT), Deep Tillage (DT), which involved manual digging up to a depth of 60cm and Berken Tillage (BT) on maize crop.

Source: Muche et al. 2017. Application of Deep Tillage & Berken Maresha to Break Hardpan, Improve Infiltration …ICAST conference,  23 May 2017, Bahrdar University.

Effect of use of Berken Maresha on crop yields

The researchers at Bahrdar University also reported the best grain yields from Berken Maresha (Muche et al. 2017).  On-farm research conducted by Gedion Shone (+251911491041) in Adama Kebele of Minjar Shenkora woreda in Amhara Region showed that grain yields of tef and other crops were increased by 28%, on average, using Berken Maresha as compared to the traditional Maresha (Table 4).

Table 4. On-farm agronomic evaluation of Berken Maresha with the traditional Maresha in Adama Kebele, Minjar Shenkora Woreda of North Shoa.

Source: Unpublished data by Gedion Shone (+251911491041)

Conclusion

The main cause of land degradation in Ethiopia has been identified to be soil erosion by water as a result of repeated cross plowing by the traditional tillage implement, Maresha. The formation of hard pans beneath the depth of operation of the Maresha plow has also contributed to poor infiltration and hence increased surface runoff. Introduction of mouldboard plows has not been successful in Ethiopia. The mouldboard plow has been found to cause land degradation as evidenced by the experiences of smallholder farmers in neighboring countries. Conservation agriculture could not be adopted in Ethiopia due to technical and socio economic factors. Attempts to replace oxen by tractors have not been successful because of lack of crop yield advantages from plowing with tractors and because labor shortage for land preparation is restricted to a small part of the farming setup, in addition to other socio economic and technical factors. A new type of tillage implement called Berken Maresha, which undertakes an innovative stepped tillage system, has been found to be effective at reducing surface runoff and soil erosion while being easier for the oxen and operators. The plow has also been found to increase crop yields. Berken Maresha reduced the number of plowing by avoiding the need for repeated cross plowing thereby reducing the time and labor required for seedbed preparation. We conclude that wider adoption of Berken Maresha by smallholder farmers in Ethiopia and other sub-Saharan African countries can lead to a sustainable agriculture.

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