Design of Manually Operated Four Rows Rice Seeder

In Ethiopia, rice is one of the targeted agricultural products that has received adequate attention in the promotion of agricultural output. It is regarded as the “Millennium Crop” and is anticipated to help ensure food security in the nation. As a result, over the past few years, its production has increased. Despite the growth, there are still a lot of production system issues that need to be resolved, with planting technique leading the list. The farmers continued to use time- and labor-intensive traditional seed-broadcasting techniques, which led to a sharp reduction in output due to an unfavorable plant population. Consequently, in order to maintain the ideal plant density and get around the issues with the conventional method of disseminating the seed on the farm; there was efforts have made to design suitable planting machine for rice. Then depends on the binary dominance matrix traditional seeding techniques (broadcasting), manual planting technique in rows and the newly designed manually operated four rows rice were evaluated and it was found that newly designed seeder was better than manual method in all parameters. The machinability aspect, which comprises installation, simplicity, durability, choice of material, machine, low pricing, and prolonged life span when operated with high utilization with minimal downtime, was properly taken into account in order to achieve this design target and goals.


INTRODUCTION
Ethiopia's economy is based on agriculture, which accounts for over 46% of GDP, 83.6% of employment, and nearly 80% of foreign export revenues. Tiny-scale farming accounts for 90-95 percent of Ethiopian agriculture's production, with 14.2 small subsistence households having an average of 0.89 hectares of land each (CSA, 2014). In Ethiopia, rice farming is a relatively new development. When wild rice (O. longistaminata) was discovered in the marshy and wet portions of the Fogera and Gambella Plains, Gebey et al., (2012) believed that efforts to introduce rice into Ethiopia had already begun. In Ethiopia, the potential area for rice cultivation is thought to be around 30 million hectares, of which more than 5 million ha are very appropriate, according to the MoARD (2010) assessment. According to CSA, MoARD, and Gebey et al. (2010) and CSA, (2009), the crop's area and output are on the rise. Ethiopia's current rice-producing regions are Amhara, SNNP, Oromia, Somali, Gambella, BeniShangulGumuz, Tigray, and Afar. Compared to its potential, Ethiopia has a small quantity of land planted in rice. The amount of imported rice has increased along with output levels. The Ethiopian government bought 25,667 tons of rice in 2008 and 30,082 tons in 2009, respectively. If rice output keeps rising, it is anticipated that the nation will soon be able to replace imports and begin exporting (MoARD, 2010). Generally speaking, rice has enormous potential and may significantly impact Ethiopia's socioeconomic development, food and nutritional security, income production, and poverty alleviation. Farmers in many parts of Ethiopia have expressed a strong interest in rice farming and routinely ask for new technologies. The crop has been designated by the government as "the new millennium crop of Ethiopia" in order to achieve food security because of its significance and potential. However, the lack of pre-harvest, postharvest, and processing technologies, as well as a lack of knowledge on how to use it, were among the biggest constraints on rice production in Ethiopia, according to Tesfaye et al., (2005). Despite this enormous potential, Ethiopian rice farming is largely traditional, with the majority of participants being small-scale farmers with modestly sized farms. Similar to this, there aren't many rice production processes that are mechanized, including soil cultivation, planting, harvesting, and threshing. The majority of farm tasks are carried out by hand, with the aid of simple hand tools, or with the aid of equipment pulled by animals. One of the biggest mechanization issues addressed was the planting process, which was caused by the lack of an appropriate rice planter or seeder. For the purpose of disseminating rice seeds by hand, farmers typically utilize this technique. It is evident that the conventional method of planting cannot maintain the ideal plant density in the field while evenly distributing the seed. Low efficiency and excessive costs are the inevitable results. In comparison to conventional hand broadcasting techniques, it was investigated if rice seeding by mechanical means could provide the ideal plant population and attain high field capacity. Additionally, it is simple to cultivate when the pattern is uniform in rows, and the rows offer the chance to employ an inter-row cultivator. Devnanai, (2002a), Devnanai, (2002b), Tajuddin, and Rajendran, (2002) among many others, have claimed that direct sowing of paddy using a drum seeder has led to lower production costs and Am. J. Food. Sci. Technol. 1(1) [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]2022 higher yield when compared to manual transplanting and broadcasting approach. The first issue was that when the grains were repeatedly discharged from the drum through the orifices, the drum's percentage of fill decreased. This resulted in a non-linear change in the grain flow rate, which again affected plant uniformity and, ultimately, crop production. The second issue was that the seeds continued to fall while rotating near the top of the field, potentially wasting better seed. Third, it required frequent refilling and was challenging to gauge the quantity of seeds inside the drum. Even though the machine has these restrictions, Ethiopian farmers find it difficult to obtain and utilize this kind of equipment due to economic issues and the machine's lack of availability in the nation. In light of the aforementioned constraints, it is necessary to construct a suitable rice seeder using materials that are readily available locally. Therefore, an effort was made in this work to address issues with the traditional methods of planting rice (both broadcasting and row dropping) by creating a four-row rice seeder that is both technologically and economically feasible. The general objective of the project was to design a four rows rice seeder with the following specific objectives.  To develop functional structure for four rows rice seeder.  To prepare 3D and 2D drawing of the rice seeder.  To prepare exploded drawing of the seeder.

MATERIALS AND METHODS Design procedures
This study was carried out after studying different research reports which are mentioned in the review of literature. Both primary and secondary sources of information have been exploited to conduct the study. The project was conducted using three treatments; Traditional or Local planting (broadcasting), and Traditional/manually (dropping in rows) rice seeder and manually operated four rows rice seeder. Seed rate, seed spacing, planting date, and plant population were the factors used for comparison. The methods to be used in this design are: The gathering required information which is associated with agricultural operation. Studying the properties of rice seed. Careful consideration and analysis on various parameters led to the selection of the best suitable concept for detailed design formulation will be done through the use of a binary dominance matrix.
• The conceptual design of an appropriate system to meet their needs.
• Modeling (using Solid work 2020 Computer Aided Design software).
• The determination on whether their problem will be solved.
• Specifying material to be used for each component.

Conceptual Design
At this point, the designing of the rice seeding machine begins with the fundamental approach to developing a new system in compliance with technical requirements. Since rice production in our country is still ongoing, seed drilling machines will be developed in accordance with demand, as noted in the literature, as one of the technical transformations of rice product development.

Abstraction
This part is used to identify the general criteria of the Rice seeding machine specially, • To develop best drilling system (accurate line spacing as possible) • To decrease energy consumption • To reduce weight or space required • To significantly lower initial cost as possible • To improve production methods

Problem Formulation
• Add the Rice seed in its bucket • Start the operation • Counting amount of rice seeds • Avoiding stick property of drilling material • Metering space between row • Starting drilling the Seed

Detail design development Design Consideration
The four rows rice seeder for direct seeding rice was designed as a functional and experimental unit. The design of machine components was based on the principles of operations and lab tests. It was compared with the compared conventional method, to give a correct shape in form of design. The mechanical design details were also given with due attention so, that it gave adequate functional rigidity for the design of machine.

Agronomical Considerations
Rice agronomist recommendations; • Seed rate; it should be in the range of 50 -80kg/ha, • Row to row distance given 20cm, • Plant to plant distance should be 2 -3cm, and • Measured values (i.e. bulk density of paddy/Rice 689kg/m3, angle of repose 360) were considered.

Design concept
A set of customer needs and target specifications serve as the basis for the concept generation process, which yields a series of product concepts from which we can create the final specification (Ulrich, 2020). In order to address issues with the current manual, traditional method, low cost automation was introduced. There are several unsure planting devices in this mechanism, like rice row seeding. The concept of the work is, • Observe the manual methods to identify the important process variables.
• Quantify the important method.
• Investigate all areas of automated forming.
• Refine design of the machine, as this plays a major role in rural area.
With the aforementioned factors in mind, a semiautomated machine that replaces manual labor can be designed.

List
The system is more probably chosen what it's seeking by fulfilling the following general requirement.
• Small in size to transport from place to place • Less Number of components • More accurate system as possible • Safe and Easy to operation • Manual power source • Less initial cost • Easy to assemble and Maintainability

Concept Generation Functional structure
Based on the problem related with rice seeding and assessing the literature of existing planting techniques we should have to design the new system. So let's construct the functional structure as follow:

Concept Selection
The process of selecting a concept involves assessing it in light of the needs of the client and other factors, comparing its relative merits, and choosing one over another for further research, testing, or development. The following potential other options will be considered while evaluating the variant. Due to the focus of this project being on rather damp soil conditions, we have neglected using another power source for machinery. The system may then go to the darkened region as follows after creating the decision tree. The decision is made using a

Decision Tree
Standing from the above possible alternative option system, we do have construct the following decision tree

Selection of working Principal Variants
From the aforementioned decision tree, which contains those 10 potential seeding system combinations, we must choose the best system. Then, only using the following criteria, they have narrowed the options down to a few.

Assessment of Values and Determination of Overall Values
The values are expressed in points of use value analysis approaches by giving 1 for more important criterion and 0 for less important criterion in a given pair of criteria to be evaluated.
Am. J. Food. Sci. Technol. 1(1) 10-24, 2022 Excellent, Complete satisfaction, objective satisfied in every aspect 85 Very Good, Extensive satisfaction, objective satisfied in all of important aspect 70 Good, Considerable satisfaction, objective satisfied in the majority of aspects 50 Fair, Moderate satisfaction, a middle point bin complete and no satisfaction 25 Bad, Minor satisfaction, objective satisfied in some but less than half of the aspect 10 Failure, Minimal satisfaction ,objective satisfied to very small extent 0 No satisfaction, objective is not satisfied in any aspect Un-weighted Overall Value was calculated by: Weighted Overall Value was calculated by

Concept variants result of power source in decision matrix
Three power sources are considered to sow rice with different range of rate within the specified time according to their capacity. These concept variants are; A=Single Man, B= Single man and single animal and C=Single man with pair of animal.
Here as shown in the table, the maximum rating is 78.03

Concept variants result of Seeding techniques in decision matrix
Three planting technique are considered to sow rice with different range of rate within the specified time according to their capacity. These concept variants are Traditional (Broadcasting), Manual row seeding, and Four rows rice seeder. A= Traditional planting (broadcasting), B= Four rows rice seeder and C= Manual seeding techniques (dropping seeds manually in rows) From the decision making matrix the maximum value of

Concept variants result of Hopper type in decision matrix
The hopper is a device in which the seeds to be planted are kept before their gradual release into the furrowed tunnel. The amount of seed depends upon the size of the seed hopper. Four concept variants are considered to design the four rows rice seeder. These concept variant are Cylindrical, Conical, Trapezoidal, and Rectangular hopper types. Let denoting A= Cylindrical, B= Conical, C= Trapezoidal and D= Rectangular Here as shown in the table, the maximum rating is 85.53 and hence concept variant C is selected as the best concept or alternative. Therefore Trapezoidal shape is the most appropriate hopper needed to hold rice seed.

Concept variants result of Furrow opener type in decision matrix
Furrow openers are parts of a planter that are used to open furrow so that seed is placed at a specific depth below the surface. The design of furrow openers of seed planters varies to suit the soil conditions. Here the variants to be used are, A=Stub runner, B= Hoe type, C= single disk type and D= Double disk. From this decision matrix, the best concept variant is concept A which is 78.55.So Stub runner type is chosen to open the furrow for seeding machine

Concept variants result of Ground Wheel type in decision matrix
The ground wheel is the power transmission device to provide motion to the ground wheel shaft and rotating metering shaft. For our design let us consider the matrix of three variants, A= Wood wheel, B= Iron wheel, and C= Pneumatic wheel.
As we can see from the above decision matrix concept B which is 83.745 is the best variant concept. So, ground wheel of Iron cover type will be chosen for the design.
Description and Design requirements of the manually operated four rows rice seeder Description of row seeding machine As the name suggests, a manually driven four-row seeder was created. It has four rows, each of which has its own hopper, and it uses a rotating shaft as a metering mechanism. Because there are holes all the way around the shaft, when the shaft's holes are in the lowest position, the seeds fall out due to gravity. The ground wheel and four hoppers were fixed on the shaft; but, they have not rotated while the ground wheels are rotating. Paddy stored in the hopper and the seed flow to the metering shaft is controlled by the cut-off mechanism. One operator could pull the implement using a long beam handle that was provided. The paddy seed was covered during planting by the chain attached made of angle iron at the bottom of the machine's back end. The operator could regulate the unneeded seed flow and seed waste during the turning trip by standing up, spinning one of the ground wheels, and setting the other ground wheel to the idle position. This machine was ideal for row planting of a variety of crops, including wheat, barley, soybeans, sorghum, etc. since it had holes on the spinning shafts that were provided based on the conventional seed-seed and row-row spacing. For this particular design, it was simply taken into account as paddy or rice seed. Typically, a seeder consists of drive wheels, a frame, seed hoppers, metering systems, furrow openers, and furrow covering tools.

Design requirements of the Seeding Machine
In order to start the design, depending on many literatures the following assumed values were taken in to consideration. > Speed of operation 1 -3km/hr, > Machine weight 12kg, wheel diameter 28cm), Where C_R = Rolling resistance m_wt = machine weight = 12kg = 58.86N i= maximum gradient of the ground, let 1% The rolling resistance can be found by using the following formula: At first, wheel revolution and machine weight on wheel would be calculated as follows: > Peripheral distance = D = *28cm=0.88m, > As wheel covers 1.89m/rev, at 1m/s it covers (1m/s) Since the machine has two ground wheel, Machine weight, M wt on wheel equals the machine weight divided by two, m wt = 58.86N Power developed by the operator According to Campell et al. (1990) the power of useful work done by human being is given by: HP=0.35-0.092logt……………………………3 Where, HP = horse power developed during time t t = time in minutes Now, for 6 -8 hours continues work the power developed by the operator would be HP=0.35-0.092log(360 minor 480)=0.115-0.103 hp Let's take the average of the ranges; it becomes = 0.109hp. Therefore, based on the calculation above, the power of productive labor created by a typical human worker is equal to 0.109 horsepower. We can use the following formula to convert this power into force: Let the operating speed of the machine be 1m/s, therefore by rearranging equation 2 we can get Hence, force developed by an average human worker = 8.175kgf The Torque produced by the driving wheel Torque produced by the driving wheel, Tw is one of the required data to calculate the torque produced by the driving wheel for both shaft analysis and wheel analysis. Consequently, it was determined utilizing the following formula: T_W=F F *D W /2…………………………………….9 Where, T W = torque produced by the driving wheel F F = Force required maneuvering the machine, kgf D W = diameter of the wheel, 0.28m Therefore, substituting the values in equation 9 we can get; Tw = 21.23N X 0.14m = 2.972N.m Power required driving the planter Equation 2.9 determined the machine's one-person operability; this property may also be represented in terms of power, thus the following equation was used to compute it: P m =T W N W ……………………………10 Where, N W = wheel revolution in rad/sec, P m = 2.972N.m x (1.136 x 2 ) = 21.21 watt. Since 1kw equals 741hp, it became 0.02121/0.741=0.0286hp Therefore, Po of operator much greater than Pm demand of the machine, so again this shows us it is safe to operate by one person(i.e. 0.109hp of the operator produced greater than 0.0286hp of the power required by the Am. J. Food. Sci. Technol. 1(1) 10-24, 2022 machine, so we can conclude that it is easy to operate).

Mainframe
The planter's frame, which serves as the platform for other components to be affixed, is its skeletal framework. The main frame's material was chosen to achieve the desired strength and reasonable weight. The frame's design was also influenced by the components that would be put on it. To provide the necessary strength and rigidity while taking into account the orientation and attachment of various components, such as hoppers and handle beams, a mild steel sheet metal with a thickness of 2mm, width of 80mm, and length of 710mm was chosen. The pulling beam channel and seed collecting hoppers were directly mounted in the middle of the frame using the proper nuts and bolts that had holes for assembly adjustments. Provisions were created during the frame's design process to fix the adjustable hopper and pulling beam placement at a 20 cm distance, or the distance between two rows. As illustrated in Figure 7(a) and (b) below, the pulling handle was attached to the frame's center section at the necessary spacing and in accordance with the ergonomic criteria.

Design of Seed Hopper
The hopper is a tool used to store planting seeds prior to their slow release into the tunnel's ridges. The size of the seed hopper determines how much seed it can hold. The trapezoidal hopper's four distinct compartments for holding and releasing seed are installed on the spinning shaft and supported by the frame to lower maintenance expenses. They share the same material and are the same size. Mild steel sheet metal with a thickness of 1.5 mm was utilized for construction since it is widely accessible and reasonably priced. To make opening easier, the hopper also incorporates a cut-off controller. Figure 8 depicts the design and measurements of each hopper chamber. When designing a hopper, the necessary volumetric efficiency, bulk density (689 kg/m3), and angle of repose are taken into account. The hopper was designed to ensure proper flow of seeds by the action of gravity only.

Weight of the Hopper
Since the seed attached to the metering hoppers have equal dimensions and made from the same material, the area of the single hopper used for the rest three hoppers was estimated from the following equations (

Design of the seed metering mechanism
The seed sowing machine's metering system, which distributes seeds consistently at the desired application rates, is its brain. The drum served as measuring mechanisms in this instance (figure 9). However, the hopper's purpose as a feeder was employed, and the shaft then metered the seeds. As previously indicated, the shaft of this machine served as a measuring mechanism and was used to plant paddy rice seed or rice grain in rows. Therefore, it was decided to compute the number of holes on shafts in each hopper using the following formula: n=πD/(I×X)…………………………………17 Where, n = number of holes on the drum D = diameter of the shaft, it takes 4.1cm X = required seed to seed spacing, it takes 2cm I= ratio of wheel to metering shaft rotation, 1:1 Therefore, substituting the values in eq. 34 we found that; n=(π*4.1cm)/2cm=6.44=takes 7 holes The length(l), width(w), and thickness(t) of 50 seeds were taken, and the size of the hole was calculated based on the average geometrical mean of the rice grain. According to Yonas L., (2017) their geometrical mean average was calculated using the following equation and came out at 2.95mm. We used 6mm for the design. D g =∛(L*W*T)…………………………….…18 Where: -L = mean length (mm) W = mean width (mm) T = mean thickness (mm) D g = mean geometric diameter (mm) Figure 9: Seed metering shaft

Design of Furrow Opener
The components of a planter known as furrow openers are used to open a furrow so that seeds can be planted at a particular depth below the surface. Furrow openers for seed planters come in a variety of designs to accommodate different soil types. Furrow openers of the adjustable curved stub runner type were created to prevent seed rebounding, roll over impediments, and increase seed placement accuracy at various planting depths. Furrow openers of the stub runner type are appropriate for usage when it is necessary to penetrate agricultural residues or hard terrain. They can be kept quite clean, which makes them more effective than permanent openers in wet, sticky soils. Because the depth can be regulated by using the slot supplied on the furrow opener for the purpose of altering the depth of the seeder, curved runner furrow openers are particularly well fitted to medium or shallow seeding of row crops that are crucial in regard to planting depth. The furrow openers were made of mild steel sheet metal that was 2 mm thick, bent, and had dimensions of 164.5 mm in height by 152 mm in width. They were then connected with a shaft and a furrow opener connecter using slotted nuts and bolts.

Adjustable Seed Covering
Planters should be made to compact the earth, push the seeds into the compacted dirt, then cover the seeds with loose soil in order to achieve the best outcomes for germination and emergence. The capillary continuity between the lower moist soil layers and the upper layers in which the seed is placed, as well as between the seed and soil immediately surrounding it, is improved by increasing the seed/soil contact below and around the seed. The soil just above the seed row should be left loose to reduce crusting and encourage simple emergence. In order to prevent birds from dropping soil, it is also crucial that the grain is covered in seed. The specially created furrow Figure 11: Seed covering mechanism covering tools enable optimum soil coverage over the seeds in the furrows. The material used for the design was mild steel flat iron of 980*140*3mm positioned and fitted immediately at the back of the seeder hopper two ends

Pulling Beam and Handle
Pulling beam is principal parts used to join the main seeder parts and the handle used for pulling forward the seeder during planting. For the design Single circular beam having 36mm and 1240mm diameter and Length respectively made up of wood for the purpose of decreasing the weight of the machine was selected. The beam was hinged to the hitch. The pulling beam was attached to the frame by using of the frame and beam connecter used as a hitch at one end and attached to the handle holder on the other end as shown on Figure12 below. In order to transfer the planter from one location to another during planting operations, a handle is used to supply the pulling force from a human operator. The planned handle was made of a circle of wood that measured 865 mm in length and 36 mm in outer diameter. Through the use of connecting bushing and nuts and bolts, the handle was fastened to the pulling beam. The handle on the seeder was primarily designed to regulate planter pull when sowing and turning in the field. The length of the handle and pulling beam were designed with ergonomics and surface smoothness in mind.

Shaft design and analysis
A shaft is a rotating machine element which is used to transmit power from one place to another. The power is delivered to the shaft by some tangential force and the resultant torque (or twisting moment) set up within the shaft permits the power to be transferred to various machines linked up to the shaft. In other words, we may say that a shaft is used for the transmission of torque and bending moment. The various members are mounted on the shaft by means of keys or splines. For this project hollow shaft having the internal diameter of 8.5mm and outer diameter of 41mm was designed. These types of shafts are stronger per mass of material, for particular power transmission, it requires minimum weight, and they may be forged on mandrel, thus making the material more homogenous than would be possible for the solid Shaft. The stresses, torques, and bending moments generated in the shaft during operation must be seen in relation to the shaft that the seed hopper assembly is mounted on. When power is transferred from the ground wheel to the seed hopper, the shaft is intrinsically subjected to a torsional moment, or torque, at a specific rotational speed. As a result, the shaft develops torsional shear stress. Additionally, a shaft typically carries the load from a hopper or seed box, which applies pressure to the shaft in a transverse orientation (perpendicular to its axis). The shaft develops bending moments as a result of these transverse forces, necessitating a consideration of the stress from bending. Because shear stresses and regular stresses from bending occur at the same time in these shafts, integrated stress analysis is actually necessary. Where, (R1and R2) or (F m )= the Ground reaction due to the sum of machine weight, and weight of seeds carried by the ground wheel. F m = 12kg + 10kg = 22kg or 215.82N F f = force driving the wheel, equals13.75N, we found it Rw h = wheel reaction at one end in the horizontal direction.
Rw v = wheel reaction at other end in the vertical direction.
Rh (a,b,c) = weight of seed hoppers including the seed at full load at point Here, we established the ideal shaft diameter and used the following procedures to determine the forces acting on the shaft and how much of each force they depend on: Finding the load exerted on the shaft The seed hoppers are what put pressure on the shaft. The following formula can be used to determine the weight coming from the seed hoppers; (since the seed box stands on the shaft with four foot, the load should be divided in to four). As stated above, it was made to hold 6 kilogram of rice seed.
Wh Thus, all forces acting in the horizontal direction become zero, and we draw the conclusion that neither a shear stress nor a bending moment exist.

Determining the maximum bending moment
Finding the product of the above-found vertical and horizontal seconds was the next stage. Consequently, we can apply the following formula to this: The torque on the shaft The power transmitted from the driving wheel to the shaft with 1:1 ratio, i.e. directly, hence torque produced at the wheel and the shaft are equal, 1.925N.m or we can also calculate using the following formula: P=T 1 N 1 =T 2 N N ………………………….24 Where, p = power transmitted T1 = torque produced at the wheel, equals 1.925N.m (which was found by eq. 24 above) T2 = torque produced at the shaft, which is equal, 1.925N.m N1 = angular rotation of the driving wheel, =1.136 rev/s or 68.2 rev/min (taken from the initial mentioned parameters above) N2 = angular rotation of the shaft, 1.136 rev/s or 68.2 rev/min (because of 1:1)

Design of Ground wheel
The ground wheel is the power transmission device to provide motion to the ground wheel shaft and rotating metering shaft. The seed hoppers were made fixed on the shaft by using bushing and keys. Lug type wheel was used for designing of the ground wheel because of its suitability to use under wet or sticky soils; whereas pneumatic wheels fail to work. Ground wheel of 280 mm diameter was selected for the designing of the wheel. The wheel is made of M.S. Rod (1.5 mm diameter) and width is kept 60 mm. The spokes were made up of mild steel flat Iron of 1.5 mm thickness 6 spokes were provided on each wheel extended 130 mm towards Centre and maximum width at the both ends was kept 45mm and welded with the bush having diameter of 42 mm and the length of bush is 100 mm. Disk plates having 47mm and 4mm diameter and thickness respectively and also Lugs are provided on the ground wheel for better traction of machine on the field the lugs are made of G.I. Sheet of 6 gauge thick.

Determination of Seeder performance and capacity
Field capacity and efficiency were determined in accordance to the recommendation made by Kepner (1978) and using relevant parameters that included effective operation time, turning time and time losses due to obstructions on the field. From the data gathered working speed (km/h), effective field capacity (ha/h) and field efficiency (%) were estimated using the expressions below (Kepner1978)

Manufacturing Process
This chapter covered a detailed explanation of how each machine component of the seeding machine was made. This stage of the manufacturing process aids in producing the machine locally using materials that are readily available. The appropriate machinery and tools are utilized as needed.

Cost Estimation and Cost of Operation
By figuring out the cost of various components, the unit cost of a manually operated four-row rice seeder was established. Cost analysis is a crucial component of technology design and production that helps ensure the dependability and affordability of the technology. Individual components or functional groups can be used to determine the cost of a subsystem for a given system (carrying out a single function). The overall system expenses are calculated by adding these expenses collectively. The cost estimation method begins with a set of technical drawings for the assembly's component parts and figures out the price of each activity related to component manufacture, assembly, and finishing.
Eliminating pointless processes has a significant impact on reducing manufacturing process costs. This can be accomplished through careful planning, operating in succession, and grouping individual activities or groups of operations. the following benefits of grouping operations;

Direct material total cost
To determine the total cost of direct materials used in the manufacture of the manually operated four rows rice seeder a material balance and flow sheet should be developed. Once the materials balances established, raw material prices must be assessed and identified. Therefore the materials and their current cost needed to manufacture the seeder were studied from the current markets.
Cost summary of the Manually Operated Four rows Rice seeder

RECOMMENDATIONS
> There is need to create awareness among the farming communities on adoption of newly designed technologies to increase and improve their agricultural production. > There is need for development of low cost Animal Operated or tractor mounted high efficiency Rice seeder for farmers for more mechanization of their agriculture.
> The row planter prototype is needed to be fabricated, tested and demonstrated in the farmer's field.
> Promotion and dissemination of the technologies has to be done to end users.
> Adjustable seed metering mechanism should be used to use the planter for different Rice varieties and crops.

CONCLUSION
In Ethiopia, rice is one of the targeted agricultural products that has received adequate attention in the promotion of agricultural output. It is regarded as the "Millennium Crop" and is anticipated to help ensure food security in the nation. As a result, over the past few years, its production has increased. Despite the growth, there are still a lot of production system issues that need to be resolved, with planting technique leading the list. The farmers continued to use time-and labor-intensive traditional seed-broadcasting techniques, which led to a sharp reduction in output due to an unfavorable plant population. Therefore, attempts were undertaken to design a suitable planting machine for rice in order to address the issues with the conventional method of spreading the seed on the farm and maintain the ideal plant density. the binary dominance matrix determines It was determined that the novel constructed seeder outperformed the manual approach in all aspects. Traditional seeding techniques (Broadcasting), Manual row planting technique, and the newly created Manually Operated Four Rows Rice were all assessed. The machinability aspect, which comprises installation, simplicity, durability, choice of material, machine, low pricing, and prolonged life span when operated with high utilization with minimal downtime, was properly taken into account in order to achieve this design target and goals. The designed machine "Manually Operated Four rows Rice seeder machine" can help to substantially reduce the human labor involved in planting and also reduces the time used for seeding operation on small farms. The designed seeder was easy to operate and repair, applicable for different sizes of grains according to their physical properties, do not break the Rice grains during seeding process. Design permits fabrication from locally available materials.