Design, modification, and manufacture of animal-drawn secondary tillage implements for wheat-based light soil farming systems in Misrak Bedawacho District, Central Ethiopia

Abstract

This study focused on the design modification, manufacture, and performance evaluation of animal-drawn secondary tillage tools for furrowing in a wheat-based light soil farming system in 2nd Chefa Kebele, Misrak Bedawacho District, Hadiya Zone, Central Ethiopia. The objective was to improve the efficiency and effectiveness of the traditional maresha plough while maintaining compatibility with local farming practices. Field experiments were conducted under actual farming conditions using pairs of oxen, comparing traditional and modified implements based on weight, tillage depth, rake angle, pulling force, draft force, field capacity, efficiency, structural safety, and soil physical properties. The modified tools were lighter and incorporated a reduced rake angle and multi-plough configurations to enhance performance. Results showed significant improvements, with working time reduced from 6.89 h to 1.98 h for 0.25 ha and field capacity increasing from 0.036 to 0.126 ha/hr, while field efficiency reached up to 99.21%. Although draft force increased slightly with additional ploughshares, pulling force remained within manageable limits. Structural analysis confirmed that all components operated safely within allowable stress limits. The modified tools also improved soil plasticity and moisture retention, supporting better crop establishment. In conclusion, the modified animal-drawn tillage implements offer a practical, efficient, and sustainable solution for smallholder farmers by enhancing productivity and reducing labor and animal fatigue. It is recommended that these tools be promoted through local fabrication, extension services, and farmer training, while further studies should assess long-term performance, adaptability, and adoption across different agro-ecological conditions.

Introduction

Agriculture remained the backbone of Ethiopia’s economy, employing the majority of the labor force and underpinning national food security¹. In Central Ethiopia, the Hadiya Zone is one of the major wheat-producing areas, where smallholder farmers relied predominantly on animal traction and traditional implements for land preparation². In this regard, the central research question of the study focused on how the design and modification of animal-drawn secondary tillage implements could enhance operational efficiency, minimize labor intensity, and increase wheat productivity in the Misrak Bedawacho Distric³.

According to the available research, using farm machinery can have a variety of positive effects for rural development and smallholder agriculture⁴. With over 70% of farms being less than two hectares in size, full tractor-based mechanization was limited, making animal-drawn implements the most practical and accessible form of mechanization for smallholders⁵. By 2050, global population is expected to reach 9.6 billion. As a result, the consumption of staple cereals, including rice, wheat, maize, as well as fish and meat products is expected to increase dramatically, particularly in rapidly developing countries⁶. Ethiopian agriculture is vital to both the nation’s economic growth and the livelihoods of its citizens. At the scale of prevalence, wheat cultivation in Ethiopia covered approximately 1.7 million hectares annually, involving over 4.7 million farming households⁷.However, average yields in Hadiya Zone remained between 2.5 and 3.0 t/ha, which was significantly below both global averages and the attainable potential under improved management⁸. Poor secondary tillage practices had been identified as a major contributing factor to this yield gap, as they led to inadequate seedbed preparation, weak weed suppression, and unfavorable soil conditions for wheat growth⁹.

Tillage plays a fundamental role in smallholder crop production systems, especially in the mixed farming zones of Ethiopia. In Ethiopia, where wheat primary cereal crops, animal-drawn plows such as the traditional “maresha” have remained the dominant tools used by farmers¹⁰. However, these tools have limitations in terms of soil penetration, working width, and efficiency, especially in light to heavy soils common to the area.With increasing pressure on land and labor, there has been a growing need to adapt tillage implements that can improve soil preparation while remaining accessible to resource-poor farmers. Existing tillage tools, though culturally accepted, often lack durability and functional efficiency. This study aimed to evaluate the current tool use, introduce specific.

modifications to existing animal-drawn tillage tools, fabricate a prototype using locally available materials, and assess its performance under actual farming conditions¹¹.

The indirect effects of inefficient tillage practices extended beyond crop yields. Socially, heavy manual labor associated with land preparation placed a disproportionate burden on farm households, especially women and children¹² In addition, rural-to-urban migration had caused seasonal labor shortages, intensifying reliance on animal traction¹³. Economically, the inefficiency of traditional implements increased the cost of production, delayed farming operations, and weakened the competitiveness of local wheat against imported grain¹⁴.when it is suitably moist due to rains. The primary factor is that the required draft force is 2.5 times lower when the plow is finished after the land has received enough rain than while plowing dry terrain¹⁵. Additionally, repeated tilling enhances soil pulverization, which reduces soil porosity while increasing compaction (Soil compaction affects nearly all yield and yield components)¹⁶.Oxen provided the traction necessary to” pull the ploughs, preparing the soil for the seeding of early, used for crop production like wheat and flax crops. Draught animals proved to be sustainable in terms of global warming and the use of non-renewable energy as compared with agricultural machinery¹⁷.

The Ethiopian ard plough ‘Maresha’ is a tillage tool that most farmers still use for land preparation. The production of the wooden structure is based on experience, culture, and trial and error methodsThe forces considered were the pulling forces provided by a pair of draught animals, the operator input force, gravitational weight of the implement, the normal and tangential interfacial forces acting on the ploughshare and wooden side-wings and the inertial force¹⁸.An implement made up of a combination of soil working tools was developed and tested. The implement was intended to enable 45–55 hp tractors to complete a seedbed in a single pass for both dry and wet land crops¹⁹. Many researchers have used various approaches for predicting draft force, including analytical, empirical, and numerical methods²⁰.

Tillage, the mechanical manipulation of soil, had long served as a foundation of agricultural development by improving aeration, water infiltration, and seedbed preparation¹⁶. Globally, tillage practices varied with environmental conditions, soil type, and cultural traditions, while draft power influenced depth and intensity. Animal traction generally achieved 10–20 cm, whereas tractors reached up to 40 cm²¹ Deep tillage improved root penetration and water dynamics but risked erosion if poorly.

managed²². Traditional lightweight ploughs remained adaptable and accessible but required walking over 60 km to cover a hectare, limiting efficiency²³. Despite this, indigenous ploughs persisted due to affordability and cultural attachment²⁴. In some areas of Ethiopia access to oxen is considered to be a more important production resource than land. The reasons for oxen’s strong position there are related to the predominance of cereal cultivation, dry climate and heavy soils. In parts of Ethiopia there are more oxen than cows. Households with a pair of oxen are in general the richest households and those without oxen have to pay up to 50% of the harvest to have their land ploughed²⁵.

Previous studies demonstrated that the traditional Ethiopian maresha plough was effective for primary tillage but inadequate for secondary operations such as seedbed finishing and weed control²⁶. Modified implements, including animal-drawn harrows and tine weeders, had been tested both in Ethiopia and neighboring countries, showing improvements in soil pulverization, weed suppression, and reduced draft power requirements¹¹. These findings partially resolved the question of whether animal-drawn tool modification could improve field efficiency under smallholder conditions. However, unresolved issues persisted, particularly regarding affordability, durability, and adaptability of such tools to Ethiopia’s diverse soil types and cropping systems²⁷.

Despite these advances, significant knowledge and practice gaps remain, especially in wheat based systems in Southern Ethiopia. Most design improvements have been concentrated in Oromia and Tigray, with limited attention to the unique agroecological conditions of Hadiya Zone and Misrak Bedawacho District²⁸. Secondary tillage operations such as seedbed refinement, residue management, and furrow or ridge finishing are particularly under-researched, even though they are crucial for cereal production. Moreover, many studies focus narrowly on tool geometry and draft requirements, overlooking critical adoption factors such as ergonomics, durability, and ease of repair²⁹. Addressing these gaps requires a holistic approach that integrates design modification, local manufacture, and performance analysis under real farming conditions, thereby ensuring both technical effectiveness and socio-economic feasibility³⁰.

Soil degradation added another dimension to the problem. Studies showed that repeated tillage with inappropriate implements increased soil pulverization, reduced porosity, and caused compaction, all of which negatively affected yield and yield components³¹. While improved tools were shown to reduce these negative effects, their dissemination in Ethiopia remained limited³². The Ethiopian Agricultural.

Transformation Agency (ATA) introduced mechanization initiatives such as combine harvesters in the study area, yet many farmers still relied on manual harvesting and threshing, or on animal trampling³³. This indicated a persistent gap between technology availability and farmer adoption.Therefore, this study addressed a critical gap by focusing on the design, manufacture, and performance evaluation of animal-drawn secondary tillage tools specifically suited to wheat-based farming systems in Misrak Bedawacho. The expected contribution extended beyond technical performance, as the findings also provided insights into socio-economic feasibility and farmer adoption, thereby supporting Ethiopia’s broader agricultural development strategies in productivity, mechanization, and food security.

While primary tillage using the traditional maresha plough is widely practiced in Ethiopia, secondary tillage operations often receive less attention despite their importance in crop production. Secondary tillage plays a critical role in seedbed refinement, weed control, and soil leveling, all of which directly influence seed germination and crop establishment. In wheat-based farming systems, inadequate secondary tillage frequently leads to uneven seedbeds, poor soil tilth, and increased weed competition, which ultimately reduce crop productivity. Previous studies have shown that improving secondary tillage operations can significantly enhance soil structure and crop establishment, particularly in smallholder systems where mechanized alternatives are limited³⁴. Therefore, improving the design and efficiency of animal-drawn secondary tillage implements represents a practical approach to increasing productivity while remaining compatible with the resource constraints of smallholder farmers.

Materials and methods

Description of study area

The investigation of the Misrak Bedawacho district, which is located in the Hadiya zone of the Centeral Ethiopia. The district’s main town is Shone, which is approximately 334 km away from Addis Abeba, on the route to Wolaita Sodo. It is also around 120 km from the regional city of Hawassa and 97 km from the zonal town of Hosanna. Geographically, the district’s co ordinates range from 7°9′00–8° North and 37°5′00–40°00′00 East. It is bordered to the west by the Mirab Badawacho district, to the south by the Wolaita zone, to the north by the Kembata Tambero zone, to the north by the Halaba zone, and to the east by the Siraro Badawacho district. According to the District Finance and Economic Development Office, the total population of the district is 168,752. Out of this population, there were 77,922 men (46.17%) and 90,830 women (53.6%). When looking at the gender ratio, women outnumber men. Majority of the population consists of Hadiya ethnic groups, each with their own unique language culture. Other ethnic groups in the district include Wolaita, Kambeta, Amhara, and Oromia. The primary language spoken in the district is Hadiyyissa. In terms of religion, 67.37% of the population identified as Protestants, 20.07% as Muslims, 8.02% as Catholic, and 3.58% practiced Ethiopian Orthodox Christianity (Fig. 1).

Fig. 1.

Map of study area (Yohannes et al., 2026).

Design of the study

The study followed an experimental engineering design, involving the modification, fabrication, and field evaluation of an animal-drawn secondary tillage tool. A comparative approach was employed, whereby the performance of the modified tool was tested against the traditional tillage tools (maresha) in wheat-based farming systems of Misrak Bedawacho District, Hadiya Zone, Central Ethiopia. Aditionally the study adopted the design to investigate new tillage systems and the need for improved energy efficiency of tillage operations do put an emphasis for optimizing imporoved animal drawn tillage tool design in the Hadiya Zone for smalhold farm implementation. The tool’s conformity was assessed.

against ASAE standards for animal tillage tools, ergonomic suitability, and soil-working efficiency³⁵. Design conformity was checked through dimensional accuracy in AutoCAD. Design and fabrication were carried out at the Shone politicical college Mechanical Engineering Workshop, while soil and tool performance tests were conducted in farmer fields in Misrak Bedawacho District Chefa Kebele.

Experimental design technique

Tillage tool design was modeled using AutoCAD, with focus on plow, angle, draft line, and handle ergonomics.Fabrication used mild steel for soil-contact parts and seasoned hardwood for handles. Welding, machining, and fitting were done in the workshop. Field Testing were conducted in randomized plots, with three replications per treatment. Performance measurement draft force, working speed, depth of operation, and soil field efficiency, theoretical field capacity were measured.The modified tool was compared against traditional practices using statistical tests.Design is the method of developing different ideas by considering the working mechanism and structure of the product. It is also a description of the proposed system in terms of, a set of integrated ideas and concepts, about which a design must do, behave and accomplish the stated requirements and to be understandable by the users in a way it is applicable³⁶.Tillage operations was carried out using a pair of oxen by trained person for each type of implements and draft force measured using dynamometer.

Computer-aided design (CAD) and tool development

The modified animal-drawn tillage tool was designed using AutoCAD to ensure geometric precision, structural integrity, and functional efficiency. The CAD process involved the development of detailed two-dimensional (2D) drawings and assembly layouts of the main components, including the beam, ploughshare, hitch system, and operator handle.Particular attention was given to aligning the line of draft with the central axis of the implement, thereby minimizing lateral forces and bending moments during operation. The finalized CAD drawings were used directly to guide fabrication, ensuring dimensional accuracy and consistency between design and prototype.

The design of the modified implement was guided by both functional requirements and limitations of the traditional maresha plough. Key considerations included optimization of the hitch geometry to ensure efficient force transmission, reduction of implement weight to minimize animal fatigue, and improvement of soil-engaging components to enhance.

penetration and soil inversion.Additionally, ergonomic factors such as handle height and operator control were incorporated to improve usability under field conditions. The ploughshare geometry was refined to reduce soil resistance while maintaining adequate working depth and width.

The integration of CAD-based design and experimental measurements provided a robust framework for tool development. The CAD model ensured geometric accuracy and facilitated fabrication, while the dynamometer measurements provided realistic loading conditions for stress evaluation. This combined approach enhanced the reliability, performance, and practical applicability of the modified tillage tool under smallholder farming conditions.

Measurement of draft force using a dynamometer

The draft force required to operate the tillage implements was measured using a load-cell type dynamometer installed inline between the draft animals and the implement. The experimental setup consisted of a pair of oxen, a modified animal-drawn tillage tool, and a calibrated electronic dynamometer connected using steel chains. The dynamometer was positioned horizontally along the line of pull to ensure accurate measurement of tensile force.All field experiments were conducted on a well-prepared wheat seedbed, characterized by fine tilth and uniform furrow spacing of approximately 20 cm width, to maintain consistency in soil conditions across test runs.

A digital dynamometer with a suitable capacity (e.g., 0–1000 kg) and high sensitivity was used to measure the pulling force. The device operates based on a strain gauge load cell, which converts mechanical deformation into an electrical signal displayed as force.Prior to data collection, the dynamometer was: Calibrated according to manufacturer specifications, Checked for zero error and Verified under static loading conditions. The dynamometer measures the draft force (F) exerted by the animals during tillage. The force is generated due to soil resistance acting against the implement and is transmitted through the chain to the measuring device (Fig. 2).

Fig. 2.

Dynamometer and pulling force measuring using field test.

Field measurements were carried out under controlled conditions using the following procedure:

• The tillage implement was attached to the oxen using a chain, with the dynamometer placed inline.

• The implement was adjusted to the desired working depth and width.

• The animals were driven at a steady walking speed across the test plot.

• Draft force readings were recorded continuously from the dynamometer display.

• Each test run covered a uniform distance, and measurements were repeated three times to ensure reliability.

• The average draft force was computed from the recorded values.

Materials used and method of data analysis

To predict the draft requirement soil implement interaction from theoretical analysis and experimental field will be correlated to determine the performance of technology. A pair of ox, Stop watch for measuring time, Farm land and ruler used as draft power in the field experiment because of its vast availability and common usage in the study areas. The proposed alternatives were evaluated against selection parameters. Based on pairwise ranking, the selection parameters prioritized and Each proposed concepts was evaluated to choose the optimum design by measure its overall performance.

The physical characteristics and conditions of the soil, the primary tillage tools operational speed, the productive time, the effective operating width, the depth of cut, and the amount of material handled must all be known in order to gather data on the performance of agricultural.

field machinery. Several researchers employ specialized instruments/equipment that has been custom-made or manufactured to ascertain the physical characteristics of the soil. Then, the performance indicators are will be assessed, including field efficiency (a crucial factor in determining which machine to use), effective field capacity, theoretical field capacity, material capacity, and power and energy requirements. Equation the following can be used to pick or decide the machine speed by noting the working or operation distance of the machine and the time taken to cover such distance. For each individual farm operation for each type of farm category is calculated as given by³⁷. Actual field capacity was calculated as:

1

where A represents the area covered (ha) and T represents the time required to complete the operation (hr). This method is consistent with agricultural machinery management principles described in ASAE(American Society of Agricultural and Biological Engineers) engineering standards and farm machinery management literature³⁸.

2

3

where AFC is the actual field capacity and TFC the theoretical field capacity. The formula for efficiency evaluation is consistent with conventional agricultural engineering practice³⁹ in Eqs. (2) and (3).

Description of Conceptual designing and manufacturing

Conceptual design referred to the process of generating multiple ideas by taking into account the working mechanism and structural characteristics of a product. It also represented a description of the proposed system in terms of a set of integrated ideas and concepts that explained what the design needed to achieve, how it should function, and how it should meet the stated requirements in a manner that users could clearly understand and apply⁴⁰. Figures 3, 4, 5, 6 illustrate the conceptual design, development process, and structural analysis of the modified animal-drawn tillage tools used in this study. Figure 3 presents the conceptual design stage, where different configurations of the tillage implement were initially developed to improve the operational performance of the traditional *maresha*. These designs aimed to increase working width, enhance soil penetration, and improve overall field efficiency while remaining compatible with animal traction systems. Figure 4 shows the designed configurations of the implements, including the traditional tillage tool and the modified tools equipped with one, two, and three plows. These designs were developed to evaluate how increasing the number of plows influences tillage performance and operational efficiency. Figure 5 illustrates the actual manufactured versions of the tools based on the conceptual and designed models, demonstrating the practical fabrication of the implements using locally available materials. Finally, Fig. 6 presents the designed free-body diagram of the beam, which was used to analyze the mechanical forces acting on the implement during field operation. This structural analysis helped ensure that the tool design could withstand the operational loads generated by animal traction while maintaining stability and durability during tillage activities.

Fig. 3.

Conceptual design.

Fig. 4.

(a), (b), (c) and (d) respectively traditional tillage tools, designed modified tillage tools with one plow, designed modified tillage tools with two plow and designed modified tillage tools with three plow .

Fig. 5.

(a), (b), (c) and (d) respectively traditional tillage tools, manufactured modified tillage tools with one plow, manufactured modified tillage tools with two plow and manufactured modified tillage tools with three plow .

Fig. 6.

Designed Free body diagram of the beam.

Material selection of the modified tillage tools

Material selection in Table 1, was guided by the requirement that all induced stresses remain within allowable limits under actual field loading conditions. Mild steel was selected for the major structural components of the modified tillage tool due to its favorable combination of strength, ductility, availability, and ease of fabrication. These properties make it suitable for resisting repeated dynamic loading during animal traction operations. In addition, mild steel provides adequate resistance to wear and deformation in soil-contact environments. A suitable factor of safety was incorporated in the design to account for fluctuating draft forces. This also considers variability in soil conditions such as moisture and compaction.

Table 1.

Material selection of the modified tillage tools with three plow.

Parameter	Description	Value
L1	Distance from hitch to support wheel	0.65 m
L2	Distance from support wheel to plough assembly	0.60 m
d1	Hitch pin diameter	0.02 m
D	Beam diameter	0.06 m
t	Thickness of hardend mild steel metal	0.006 m
d2	Depth of the tillage	0.15 m
S	Widith of tillage	0.02 m

Operational uncertainties caused by animal movement and field irregularities were also included. Therefore, the selected material ensures both structural reliability and long-term service performance.

The modified animal-drawn tillage tool was developed to improve soil cutting efficiency and increase field capacity compared to the traditional single-share maresha plough. The system consists of a main beam, hitching frame, support wheel, and a three-ploughshare unit mounted on a toolbar. Unlike the conventional wooden implement with limited metallic reinforcement, the improved design incorporates hardened mild steel for key structural and soil-engaging components. This enhances strength, stiffness, and resistance to wear during field operation. The beam diameter of 0.06 m and steel thickness of 0.006 m were selected to withstand bending stresses under draft load. A hitch pin diameter of 0.02 m ensures safe and efficient transmission of pulling forces from the animals. The overall layout dimensions of 0.65 m and 0.60 m were optimized to provide balanced load distribution. This configuration improves stability, reduces overturning tendency, and enhances operational performance in field conditions.

These material and design improvements enable the modified tool to operate more efficiently and consistently than the traditional plough. It maintains a uniform working depth of 0.15 m and width of 0.02 m per plough, improving soil penetration and tillage quality. The use of hardened steel reduces deformation and maintenance requirements, extending service life. Although the initial cost is higher, the tool delivers better field capacity and reduces operational delays. In contrast, the traditional wooden plough is less durable and less precise. Overall, the modified tillage tool provides improved durability, efficiency, and reliability in field operations.

Economic analysis of traditional and modified animal-drawn tillage tools

From Table 2,the economic comparison between the traditional and modified animal-drawn tillage tools reveals a clear trade-off between initial investment and operational efficiency. The modified tool requires a higher upfront cost (1500 ETB) compared to the traditional one (950 ETB), along with slightly increased annual maintenance expenses. However, this higher capital investment is offset by a significantly longer service life of five years, more than double that of the traditional tool. In terms of performance, the modified implement demonstrates superior efficiency, offering a wider working width (20 cm) and a substantially higher field capacity (0.126 ha/hr) than the traditional tool (0.036 ha/h). Consequently, the time required to till one hectare is drastically reduced from 20.7 h to 7.92 h, indicating a major improvement in operational productivity.

Table 2.

Economic analysis of traditional and modified animal-drawn tillage tools.

Parameter	Unit	Traditional tool	Modified tool
Initial investment cost	ETB	950	1500
Service life with out maintenance	Years	2	5
Average repair and maintenance cost	ETB/year	50	70
Working width	cm	15	20
Working depth	cm	20	15
Field capacity	ha/h	0.036	0.126
Average time required to till 1 ha	hr	20.7	7.92
Labor requirement	man-day/ha	4	2
Labor cost (400 ETB/day)	ETB/ha	1,600	800
Cost saving compared with traditional tool	ETB/ha	–	800
Additional investment cost	ETB	–	550
Payback period	ha	–	0.69

From a cost and labor perspective, the modified tool provides notable economic advantages. It reduces labor requirements by half, from 4 man-days per hectare to 2 man-days, which directly lowers labor costs from 1600 ETB/ha to 800 ETB/ha. This results in a net saving of 800 ETB per hectare when compared to the traditional method. Despite the additional investment cost of 550 ETB, the modified tool achieves a rapid payback period of only 0.69 hectares, making it a financially attractive option for farmers. Overall, the modified tillage tool not only enhances field efficiency but also delivers significant cost savings and improved labor productivity, making it a more economically viable and sustainable alternative to the traditional implement.

Design overview of modified tillage tools

The design of the modified tillage tool integrates multiple functional components to improve stability, force distribution, and overall field performance compared to conventional implements. The system consists of a main beam connected to a hitching frame, a support wheel for depth control, and a three-ploughshare assembly arranged along a toolbar. During operation, the pulling force from draft animals is transmitted through the beam at an angle, creating both horizontal (draft) and vertical force components that influence soil penetration. The ploughshares interact with the soil by generating resultant reactions composed of horizontal and vertical forces, while a tangential cutting force enables effective soil slicing. Proper spacing between ploughshares and optimized distances between structural elements ensure balanced load transfer and efficient tillage. Additionally, the hitch pin is designed to withstand shear stress, maintaining structural integrity under working conditions. Overall, the design enhances cutting efficiency, reduces operator effort, and improves field capacity through better force management and mechanical stability (Fig. 7).

Fig. 7.

Design overview of modified tillage tools.

Draft force analysis

The draft force required to pull the implement is generated by the traction force exerted by the by the pair of oxen. The pulling force acts along the beam at an inclination angle relative to the horizontal soil surface. This value represents the effective horizontal draft force.

required to overcome soil resistance during tillage operations.The horizontal draft component responsible for pulling the implement is calculated using:

4

5

6

where:

• F_b, Pulling force (N).

• F_d, Horizontal draft force (N).

• Fv, Vertical draft force (N).

• F_h, Hitch pin force (N).

• β_1, Beam angle (°).

Pulling force F_b = 883 N and Beam angle β₁ = 15°.

Thus,

F_d =  883Ncos (15°).

F_d = 852.91 N.

F_v =  883Nsin (15°).

F_v = 228.54 N

.

F_h = 882.99 N, F_h ≈ F_b.

This confirms that the hitch force equals the applied pulling force, since it is simply the vector magnitude. The hitch force is equal to the applied pulling force because it represents the resultant of the horizontal and vertical components of the same force transmitted from the draft animals.

Stress analysis

1. Tensile stress (σ_t) on beam.

   The tensile stress on the beam is calculated using the equation:

   7

   where:

   Cross-sectional area,

   D = 0.06 m( Beam diameter), d = 0.01 m (Bolt diameter).

   Result

   = 396,756.5 Pa (0.396 MPa).

2. Shear stress(τ) on hitch

   8

   Where:

   F_h = 882.99 N (Hitch force)

   

   d = 0.01 m (Bolt diameter).

   = 5, 624,140.13 Pa (5. 624 MPa).

3. Bearing stress(σ_b) on ploughare

   

   where:

   F_h = 882.99 N ( Hitch force).

   t = 0.004 m(Thicness of mild steel metal).

   d = 0.001 m (Bolt diameter).

   = 11,037,375 Pa (11.02 MPa).

Tangential force on the Ploughshare

During soil penetration and cutting, the ploughshare experiences soil resistance forces which can be resolved into horizontal and vertical components.The horizontal component contributes to draft resistance, while the vertical component influences penetration depth and stability of the implement.

9

Fo = F_required – ( V + F_v), F_reqired = qc*A.

Where:

F_d = 852.91 N ( force exerted by soil resistance).

β₁ = 15^o (pulling beam angle angle).

θ₁ = 20^o(Ploughshare angle).

V = 147 N(Weight of the tillage tools).

F_v = 228.54 N(Vertical draft force).

qc = 40,430 N/m² (Cone petration rsistance from mechanical soil experiment).

d = 0.15 m(depth of tillage).

W = 0.2 m( widith of tillage).

A = 0.015m²(Area of Ploughshare).

F_required =569.87 N(Total force needed to pull the tillage tool through soil).

F_o = 194.34 N(operator force).

F₃= 1,513.25 N(1.51kN).

Result

Comparison of tillage performance between traditional and modified implements based on weight, tillage depth, average pulling force, rake angle, and draft force

The results presented in Table 3 reveal clear differences in physical and operational characteristics between the traditional and modified tillage tools. The traditional single-plough implement recorded the highest weight at 16 kg, while the modified tools ranged from 13 to 15 kg. This reduction in weight indicates improved design efficiency and easier handling during field operation. In terms of tillage depth, the traditional tool operated at 20 cm, whereas all modified configurations maintained a uniform depth of 15 cm. This adjustment reflects a more controlled and optimized soil engagement. The rake angle also decreased from 20° in the traditional tool to 15° in the modified designs, suggesting improved penetration geometry. These physical modifications collectively contribute to reduced soil resistance. Overall, the modified tools demonstrate better structural and geometric optimization compared to the conventional plough.

Table 3.

Comparison of weight, depth of tillage, average pulling force, Rake angle and draft force for traditional and modified wheat based secondary tillage plow.

Types of tillage tools	Weight of tillage tool (kg)	Depth of tillage (cm)	Pulling force of (N) using daynamometer (mean ± SD)	Rake angle (°)	Draft force(N) (mean ± SD)
Traditional tillage with one plow	16	20	884.00 ± 0.82	20	830.68 ± 1.20
Modified tillage with one plow	13	15	865.00 ± 0.87	15	835.52 ± 0.98
Modified tillage with two plow	14	15	876.00 ± 2.49	15	846.15 ± 2.95
Modified tillage with three plow	15	15	883.00 ± 1.70	15	852.91 ± 2.01
LSD	–	–	3.73	–	3.59
t- value	–	–	2.36	–	2.306
p- value	–	–	0.0000077	–	0.0000017

The comparison of pulling force shows only slight variation among the different tillage configurations. The traditional tool required a mean pulling force of 884.00 ± 0.82 N, while the modified tools required between 865.00 ± 0.87 N and 883.00 ± 1.70 N. This indicates that the introduction of additional ploughshares did not significantly increase the effort required from draft animals. However, a gradual increase in draft force was observed as the number of ploughshares increased. The traditional tool recorded a draft force of 830.68 ± 1.20 N, while the modified three-plough tool reached 852.91 ± 2.01 N. This increase reflects the larger soil contact area in the modified configurations. Despite this, the variation remains relatively small. The results suggest efficient load sharing among the ploughshares. Therefore, the modified design maintains manageable force requirements while improving soil coverage.

Statistical analysis further confirms the significance of the observed differences in pulling and draft forces. The least significant difference (LSD) values were 3.73 for pulling force and 3.59 for draft force, indicating measurable variation among treatments. The calculated t-values of 2.36 and 2.306 exceed typical critical values, suggesting statistically meaningful differences. Moreover, the p-values (0.0000077 for pulling force and 0.0000017 for draft force) are far below the 0.05 threshold. This confirms that the differences are highly significant and not due to random variation. The low standard deviation values also indicate consistency in measurements. These findings validate the reliability of the experimental results. Overall, the statistical evidence supports the conclusion that the modified tools perform differently and more efficiently than the traditional plough.

Comparison of working area, working time, working speed, tillage width field capacity; theoritical field capacity and field efficiency for traditional and modified tillage performance evaluation

The comparison in Table 4 highlights a substantial performance gap between the traditional single-plough tool and the modified tillage systems. For the same working area of 0.25 ha, the traditional plough requires 6.89 h, operating at a speed of 0.62 m/s with a tillage width of 25 cm. This limited coverage results in a low field capacity of 0.036 ha/h and a theoretical capacity of 0.056 ha/h, with field efficiency reaching only 64.28%. These values indicate that much of the operational time is not effectively converted into productive field work, largely due to narrow working width and less optimized design.

Table 4.

Comparison of working area, working time, working speed, tillage width field capacity; theoritical field capacity and field efficiency traditional and modified wheat based secondary tillage tools.

Types of tillage tools	Working area (ha)	Working time (h)	Working speed (m/s)	Tillage width (cm)	Field capacity (ha/h)	Theoritical field capacity (ha/h)	Field efficiency (%)
Traditional tillage with one plow	0.25	6.89	0.62	25	0.036	0.056	64.28
Modified tillage with one plow	0.25	5.78	0.66	20	0.043	0.047	91.48
Modified tillage with two plow	0.25	2.81	0.63	40	0.088	0.092	95. 65
Modified tillage with three plow	0.25	1.98	0.59	60	0.126	0.127	99.21

The modified tillage tool, even with a single plough, demonstrates noticeable improvements. It reduces working time to 5.78 h and slightly increases operating speed to 0.66 m/s. Although its tillage width is smaller at 20 cm, the field capacity increases to 0.043 ha/h, and efficiency rises sharply to 91.48%. As the number of ploughs increases, the advantages become more evident. The two-plough configuration doubles the working width to 40 cm, cutting the working time to 2.81 h and boosting field capacity to 0.088 ha/hr, with field efficiency improving further to 95.65%.

The modified tool with three ploughs delivers the highest performance among all configurations. It completes the 0.25 ha area in just 1.98 h, with a wide tillage coverage of 60 cm. Despite a slight reduction in speed to 0.59 m/s, it achieves a high field capacity of 0.126 ha/h, closely matching its theoretical value of 0.127 ha/h, and reaches an exceptional efficiency of 99.21%. Compared to the traditional plough, this represents a major gain in productivity, time savings, and operational effectiveness, making the three-plough modified tool a far more efficient solution for wheat-based secondary tillage.

Structural safety evaluation of stress

The structural safety evaluation in Table 5 indicates that all major components of the modified tillage tool operate within safe stress limits under field conditions. The hitch pin experiences a shear stress of 5.64 MPa, which is far below the allowable 140 MPa, ensuring safe load transmission during operation. The main beam shows a very low tensile stress of 0.396 MPa compared to the allowable 250 MPa, indicating negligible risk of deformation or failure. Similarly, the ploughshare bolts are subjected to a bearing stress of 11.02 MPa, well within the safe limit of 120 MPa. These results confirm that the design maintains a high factor of safety across all components. The low stress levels reflect effective material selection and proper load distribution in the structure. This also suggests the implement can withstand variations in soil resistance and dynamic loading conditions. Additionally, the conservative design enhances durability and reliability during prolonged field use. Overall, the implement is structurally stable and suitable for smallholder agricultural applications.

Table 5.

Structural safety evaluation of stress.

Component	Stress type	Calculated stress	Allowable stress	Safety
Hitch pin	Shear stress	5. 64 MPa	140 MPa	Safe
Main beam	Tensile stress	0.396 MPa	250 MPa	Safe
Ploughshare bolts	Bearing stress	11.02 MPa	120 MPa	Safe

Soil physical properties by tillage practice

The results in Table 6 showed that tillage practice had a significant effect on some soil physical properties. The liquid limit (LL) was slightly higher under traditional tillage (41.33%) compared to modified tillage (40.13%), though the difference was small but statistically significant (p < 0.05). The plastic limit (PL) exhibited a more pronounced difference, with traditional tillage showing a higher value (39.27%) than modified tillage (34.20%), indicating that soil under modified tillage required less water to reach the plastic state. The plasticity index (PI), however, was significantly higher in modified tillage (5.93) compared to traditional tillage (2.67), suggesting greater soil workability and a wider range of moisture conditions for soil manipulation. Bulk density (BD) and total porosity (TP) did not differ significantly between practices, with values of 1.37–1.38 g/cm³ and 47.82–48.05%, respectively, implying that tillage method did not greatly affect these structural properties.

Table 6.

Soil physical properties influenced by tillage practice.

Soil physical properties	Traditional plow (mean ± SD)	Modified plow (mean ± SD)	LSD	p-value
Liquid limit (%)	41.33 ± 0.84	40.13 ± 1.07	2.89	p > 0.05
Plastic limit (%)	39.27a ± 0.83	34.20 b ± 0.70	3.21	p < 0.05
Plastic index	2.67a ± 0.29	5.93b ± 0.50	1.45	p < 0.05
Bulk density (g/cm3)	1.37 ± 0.026	1.38 ± 0.028	0.12	p > 0.05
Total porosity(%)	48.05 ± 0.99	47.82 ± 1.04	3.21	p > 0.05
Moisture content (%)	19.01 ± 1.21	21.01 ± 0.79	2.45	p > 0.05
Specific gravity	2.25a ± 0.007	2.23b ± 0.004	0.08	p < 0.05
Dry density (g/cm3)	1.15 ± 0.023	1.14 ± 0.022	0.03	p > 0.05

LSD, Least significant difference; SD, Standard deviation; means in each column followed by similar letters are not significantly different (p < 0.05).

Moisture content (MC) showed a clear distinction between the two systems, with modified plow retaining higher moisture (21.01%) compared to traditional plow (19.01%), which is favorable for crop growth. Specific gravity also differed slightly but significantly, with traditional plow recording a higher value (2.25) than modified plow (2.23). Dry density (DD) was similar in both systems, averaging around 1.14–1.15 g/cm³, but the statistical difference indicated subtle effects of tillage practice on compaction. Overall, the findings revealed that modified plow improved soil plasticity and moisture retention, creating more favorable conditions for root development and crop establishment, while the traditional plow maintained slightly higher liquid and plastic limits, reflecting differences.

Discussion

The comparison of physical and operational parameters shows clear improvements in the modified tillage tools relative to the traditional single-share plough, consistent with earlier findings in agricultural implement design. The choice of mild steel as the primary construction material in this study aligns well with findings from earlier research on animal-drawn implements. Previous studies have shown that mild steel offers an optimal balance between strength, ductility, and manufacturability, making it suitable for smallholder agricultural tools subjected to repetitive loading conditions⁴¹. In comparison to traditional wooden ploughs, which are prone to rapid wear and structural failure, the present results demonstrate improved durability and resistance to deformation. The incorporation of a safety factor to account for dynamic loading and soil variability further strengthens the design approach, consistent with recommendations in agricultural machinery design literature⁴². Therefore, the current material selection confirms and extends previous findings by ensuring both reliability and longevity under Ethiopian field conditions.

The structural configuration of the modified tillage tool also reflects significant improvements over conventional designs. Earlier studies have emphasized the importance of.

proper load distribution and tool geometry in enhancing tillage efficiency⁴³. In line with these findings, the present design integrates a main beam, support wheel, and multi-ploughshare system to improve stability and reduce overturning. The selected dimensions (beam diameter of 0.06 m and hitch pin of 0.02 m) are consistent with standard engineering recommendations for resisting bending and shear stresses⁴⁴. Compared to traditional maresha ploughs, which lack structural uniformity, the modified tool demonstrates better mechanical balance and operational control, confirming the advantages of improved implement geometry reported in previous studies⁴⁵.

From a structural safety perspective, the stress analysis confirms that all components operate well within allowable limits. The recorded tensile stress (0.396 MPa), shear stress (5.64 MPa), and bearing stress (11.02 MPa) are significantly lower than standard allowable values, indicating a high factor of safety. These findings are consistent with previous engineering analyses, which recommend conservative stress limits to ensure durability under variable field conditions⁴⁶. Compared to traditional implements, where material failure is common due to poor design and material limitations, the modified tool demonstrates superior structural integrity. This supports earlier conclusions that improved material selection and engineering design can significantly enhance implement lifespan and reliability⁴⁷.

Studies indicate that the maresha often requires relatively high draft force and has a narrow working width, resulting in low field capacity and high labor demand⁴⁸. To address these challenges, this study introduced design improvements such as reducing tool weight, adjusting the rake angle from 20° to 15°, and developing one-, two-, and three-plow configurations. Field performance comparisons between the traditional and modified tools were conducted under real farming conditions in Chefa kebele of Misrak Bedawacho District. The experiments were carried out during the normal land preparation period using pairs of oxen to reflect the practical working environment of local farmers.

The modified tools were also evaluated in terms of operator comfort, economic feasibility, and environmental sustainability. Field observations showed that improved soil penetration and smoother tool movement reduced operator fatigue during operation. This improvement was mainly due to the optimized rake angle of 15°, which helped reduce soil resistance and draft force⁴⁹. Although multi-plow configurations may require slightly greater traction power under some soil conditions, they remain suitable for smallholder.

farmers. The modified implements are simple improvements to the traditional maresha rather than completely new mechanized systems. They can be manufactured using locally available materials and simple fabrication techniques, which keeps production costs relatively low⁴⁵. In addition, animal-drawn tillage relies on renewable biological energy, reducing dependence on fossil fuels and supporting environmentally sustainable farming⁵⁰. Improving the existing maresha therefore provides a practical and culturally compatible pathway for gradual agricultural innovation in Ethiopian smallholder farming systems⁵¹.

The modification of the traditional wheat-based secondary tillage plow led to notable improvements in performance characteristics such as tool weight, rake angle, and draft force. The modified tools were lighter (13–15 kg) than the traditional plow (1.6 kg) and had a smaller rake angle (15° instead of 20°). These adjustments reduced soil resistance and made the implements easier for draft animals to pull, thereby improving operational comfort and reducing fatigue during field work. Similar results have been reported by Gebregziabher et al.¹⁸ and Sims et al.⁵², who found that optimizing implement geometry and reducing tool weight can significantly lower draft demand while improving the efficiency of animal-drawn implements in smallholder farming systems.

The modified implements also operated at a slightly shallower tillage depth of 15 cm compared with 20 cm for the traditional plow. This adjustment was intended to maintain effective soil loosening while minimizing the energy requirement for draft animals. Earlier studies have indicated that excessively deep tillage often increases draft force without providing substantial agronomic benefits, particularly in light-textured soils common in Ethiopian highlands²⁶. Study on conservation and soil management also suggests that moderate tillage depth can improve seedbed preparation while preserving soil moisture and structure⁵³.

In this study, the modified tools maintained effective soil disturbance while slightly lowering the average pulling force measured with the dynamometer (865–883 N) compared with the traditional implement (884 N).Changes in tool geometry further influenced draft force requirements. The traditional plow required 830.68 N, whereas the modified designs ranged from 835.52 to 852.91 N. Although the draft values were slightly higher for the improved tools, this increase reflected better soil engagement and more stable cutting action during operation. The modified tillage tools demonstrated improved performance through reduced.

weight and optimized geometry, which enhanced soil penetration and efficiency compared to the traditional plough. The slight increase in draft force with multiple ploughshares is consistent with findings that greater soil engagement marginally raises resistance without significantly increasing animal effort. Similar observations were reported by of Choubey (2016) and, Alvarez and Steinbach⁵⁵, who explained that draft force is strongly influenced by implement design, soil contact, and cutting efficiency.

Operational performance results revealed clear improvements in working time and field productivity. The traditional plow required 6.89 h to till 0.25 ha, while the modified single-plow system reduced this time to 5.78 h. Much greater reductions were observed with the multi-plow designs, where the two-plow and three-plow configurations completed the same area in 2.81 and 1.98 h, respectively. These improvements were mainly due to the increased effective tillage width of the modified tools, which reduced the number of passes required to cover the field. Similar findings were reported by Hunt³⁸ and Srivastava et al.³⁹, who showed that wider implements significantly improve field capacity. Studies on animal traction technologies also indicate that multi-tool configurations can enhance the timeliness of farm operations and reduce labor requirements⁵⁶.

The improvements in working width and operational efficiency resulted in higher field capacity and better use of working time. Field capacity increased from 0.036 ha h⁻¹ with the traditional plow to 0.126 ha h⁻¹ with the three-plow modification, while field efficiency improved from 64.28% to values close to 99.21%. The high field efficiency of 99.21% observed in the three-plough configuration exceeds typical values reported for traditional systems, which often suffer from time losses and limited working width. Similar improvements have been reported in studies evaluating improved animal-drawn implements and intermediate mechanization technologies⁴⁵. These findings corresponded with studies by Xie et al.⁵⁷ and Pretty⁵⁸, who emphasized that adaptive mechanization and context-appropriate implement design are crucial for sustainable agricultural intensification. Therefore, the modified tillage tools developed in this study offered a practical, evidence-based alternative to traditional systems, suitable for smallholder wheat producers seeking to improve productivity and reduce animal labor fatigue.

Previous studies emphasize that traditional farming technologies often persist not only due to economic constraints but also because they are deeply integrated with local knowledge systems and farming practices⁵¹. The economic analysis also supports the superiority of the modified tool over traditional tillage tools. Although the initial investment is higher, the extended service life and reduced labor requirements lead to significant cost.

savings, consistent with previous studies on farm mechanization in developing countries⁴¹. The rapid payback period (0.69 ha) highlights the financial viability of the technology, particularly for smallholder farmers. Earlier research has emphasized that adoption of improved tools depends on both technical performance and economic benefits⁴⁸.

The modified plow improved key soil physical properties compared to traditional tillage. It reduced liquid limit (LL) and plastic limit (PL) while increasing the plasticity index (PI), indicating better soil workability and resistance to cracking. Bulk density (BD) and dry density (DD) were higher at the surface but decreased with depth, while total porosity (TP) slightly increased due to biological activity. Specific gravity (SG) remained constant, showing no major change in mineral composition. The modified plow also showed slightly higher soil moisture content, though not statistically significant. Similar benefits of conservation tillage were reported by Li⁵⁹, who found that such practices contributed to increased structural quality and resilience under variable moisture conditions. Overall, these results suggest improved soil structure and resilience under modified tillage. In this context, the present findings demonstrate that the modified tillage tool not only enhances productivity but also provides a practical and affordable solution for sustainable agricultural intensification.

Conclusion and recomendation

The results of this study demonstrated that modifying the traditional animal-drawn secondary tillage implement significantly improved its operational and mechanical performance in wheat-based farming systems. The redesigned tools were lighter and incorporated a reduced rake angle, which helped lower soil resistance and improved the ease of operation for draft animals. Although the modified implements showed slightly higher draft force due to improved soil engagement, they provided better soil cutting and seedbed preparation than the traditional plow. The multi-plow configurations particularly enhanced field performance by increasing effective tillage width and reducing the number of passes required during field operations. Consequently, working time decreased substantially, from 6.89 h with the traditional implement to only 1.98 h for the three-plow configuration when cultivating 0.25 ha. Field capacity also increased more than threefold, indicating a clear improvement in operational efficiency and productivity. These results confirm that relatively simple design modifications to indigenous tools such as the maresha can significantly enhance tillage performance while maintaining compatibility with existing animal-traction systems. Therefore, improving traditional implements provides a practical and sustainable pathway for strengthening smallholder wheat production and reducing labor and animal fatigue in Ethiopian farming systems.

Based on the findings of this study, the modified animal-drawn multi-plow tillage implements should be promoted as an improved alternative for secondary tillage in wheat-based smallholder farming systems. Agricultural extension services, research institutions, and local fabrication workshops should collaborate to support the production and dissemination of these improved tools using locally available materials. Training farmers and local artisans on fabrication, operation, and maintenance would further enhance adoption and sustainability. Future research should also evaluate the performance and durability of the modified tools under different soil types, agro-ecological conditions, and cropping systems. In addition, studies focusing on farmer acceptance, economic benefits, and ergonomic improvements would help refine the design and support wider adoption of improved animal-traction technologies.

Author contributions

Conceptualization, D.Y., K.P.K., M.D., and M.M.; Formal analysis, D.Y., M.D., and M.M.; Investigation, D.Y. and M.D.; Methodology, D.Y., K.P.K., M.D., and M.M.; Supervision, K.P.K., M.D., and M.M.; Writing-original draft, D.Y.; Writing-review and editing, K.P.K., M.D., and M.M.; fund acquisition, M.M. The published version of the manuscript has been read and approved by all authors.

Funding

The authors would like to express their sincere gratitude to the Office of the Vice President for Research and Technology Transfer at Hawassa University for funding this research. This work was supported under the NORAD ICP-V project budget, with a focus on landscape and ecosystem management (Action Track 3: Increasing the Positive Production of Nature).

Data availability

The data supporting the findings of this study are available from the corresponding author upon reasonable request.

Declarations

Competing interests

The authors declare no competing interests.

Consent

Informed consent was obtained from all individuals participating in the field experiments and appearing in the photographs for publication in an online open-access journal. In addition, all figures were carefully reviewed to ensure that no personal names or sensitive identifying information are visible.