Department of Agricultural Engineering

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An examination of alternative fertilizer transportation, warehousing and application systems for agricultural cooperatives
(Sokoine University of Agriculture, 2004) Kilima Fredy Timothy Mlyavidoga
The difficulty of controlling cost in a dynamic industry where competitiveness and costs are changing over time has long been recognized. Conventional wisdom suggests that players who succeed in such an industrial setting are those who capture the opportunities presented by a new business environment while maintaining economic efficiency (Bello, Lohtia and Sangtani; Flint). In recent years, one of the business challenges for fertilizer suppliers in the United States has been to keep pace with the changing business environment. The changes arise from changing demand, growing global competition, increased regulations in the industry for environmental and safety reasons, and improvements in the transportation and application methods. The improvement in fertilizer distribution and application methods is by and large a reflection of changes in the physical condition and operating characteristics of highways, and changes in farm transportation and application equipment (USDA, Agricultural Cooperative Service). Changes in fertilizer demand and increased market competition are attributable to changes in farm application systems, and consolidation of farming business that has decreased the number of farms and increased the average farm size (Norton).
Assessing potential land and surface water resources available and suitable for irrigated agriculture in the wami sub-basin Morogoro
(Sokoine University of Agriculture, 2021) Malekela, Charles John
Assessing potential land and water resources suitable for surface irrigation is essential for proper planning of their utilization types. The assessment has a great role in satisfying subsistence requirements, increasing agricultural production and hence reducing poverty. Despite efforts made by various stakeholders to improve agricultural productivity by increasing irrigated areas, Tanzania is still facing a daunting task of reaching the one million hectare target of irrigated area. This indicates that land and water resources are not presently effectively utilized. This study was initiated with the objective of assessing the land and water resources suitable for irrigated agriculture along with the extent of small-scale irrigation in the Wami sub-basin. Geographical Information System (GIS) based on Multi Criteria Decision Analysis (MCDA) was used along with various spatial tools including a model builder which was used to create geo-referenced maps of land and water resources. Ten layers (irrigation suitability factors) were used in the analysis for identification of potential land suitable for irrigated agriculture. Results indicate that, based on the suitability factors about 841.39 km 2 (3.11% of the total area), is highly suitable for surface irrigation, about 18,244.41 km 2 (67.51%), is moderately suitable and 7939.87 km 2 (29.38%), is marginally suitable for surface irrigation. Furthermore, results shows that the extent of small-scale irrigation is about 1958.87 km 2 . Moreover, results indicates that, approximately 1958 km 2 of land assumed to represent the extent of small- scale irrigated areas in Morogoro region including Dakawa and Mvomero in particular. As such, the exploration of various resources as observed in this study, including land, soil and water was well demonstrated by the integration of GIS-Based Multi Criteria Decision Analysis (MCDA), and the weighted overlay technique for land suitability analysis.
Assessment of physical status of the irrigation structures in Nyarubogo irrigation scheme, Rwanda
(2024-09) Bosco,Tuyisabe Jean; Festo,Richard Silungwe; Mahoo,Henry F
The physical status of irrigation structures holds immense importance in ensuring the efficient and sustainable management of water resources for agricultural purposes. This study aimed to assess the physical status of the Nyarubogo irrigation scheme structures, which has implications for the level of performance of this irrigation scheme. Specifically, the study assessed the effectiveness of the irrigation infrastructures in terms of intake efficiency, canal physical condition, and command area development. Cross sectional study design was employed, and units for the study were randomly selected to be included in this study. Observation method were used to characterize the physical condition of the Nyarubogo irrigation scheme while questionnaire survey were used to collect data on the implication of socioeconomic characteristics on the performance, and effectiveness of irrigation system. The collected data were fitted to the irrigation structures assessment approaches suggested by Bos, Zende and Nagarajan. Analysis of farmer’s responses was through Statistical Package for the Social Sciences (Version 27). This study evaluated the physical status of about 130 irrigation structures in Nyarubogo irrigation scheme. The structures included 7 division boxes, 73 water drops, 2 aqueducts, 42 turnouts, 4 bridges, and 2 Culverts. Overall, the scheme had an effectiveness of 63.8%, with culverts, bridges, and water drops presenting more than the average functional condition of 64.38%, 75.00%, and 100.00%, respectively. The intake efficiency during this study was found to be 67% accumulated from efficiencies of sediment level (20%), embankment (35%), and sluice gate (12%) based on their weightage percentage and rank scores. The overall canal condition was good and was quantified to 70%. The command area development was exhibiting subpar performance, registering a mere 32% effectiveness. Moreover, the study evaluated how farmers' socio-economic status influenced the inadequate maintenance of the Nyarubogo irrigation systems. It uncovered numerous elements contributing to this dilemma: there was limited engagement of women and youth in agricultural pursuits, low educational attainment, challenges surrounding land ownership (specifically, land tenure), the small size of land holdings per household and a notable absence of government incentives for maintenance efforts. These factors, however, when coupled with inadequate funds derived from water fees, significantly obstruct the proper care of these irrigation infrastructures. On the other hand, high runoff due to heavy rainfall was mentioned by the majority of farmers (20.7%) among the primary causes of poor maintenance of irrigation structures. Generally, the evaluation of the Nyarubogo irrigation system structures emphasizes the uneven levels of efficacy and challenges, highlighting the necessity of focused maintenance efforts and enhanced water management techniques.
Autonomous navigation of a center-articulated and Hydrostatic transmission rover using a modified Pure pursuit algorithm in a cotton field
(MDPI, 2020-08-07) Kadeghe, Fue; Wesley, Porter; Edward, Barnes; Changying, Li; Glen, Rains
This study proposes an algorithm that controls an autonomous, multi-purpose, center-articulated hydrostatic transmission rover to navigate along crop rows. This multi-purpose rover (MPR) is being developed to harvest undefoliated cotton to expand the harvest window to up to 50 days. The rover would harvest cotton in teams by performing several passes as the bolls become ready to harvest. We propose that a small robot could make cotton production more profitable for farmers and more accessible to owners of smaller plots of land who cannot afford large tractors and harvesting equipment. The rover was localized with a low-cost Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS), encoders, and Inertial Measurement Unit (IMU)s for heading. Robot Operating System (ROS)-based software was developed to harness the sensor information, localize the rover, and execute path following controls. To test the localization and modified pure-pursuit path-following controls, first, GNSS waypoints were obtained by manually steering the rover over the rows followed by the rover autonomously driving over the rows. The results showed that the robot achieved a mean absolute error (MAE) of 0.04 m, 0.06 m, and 0.09 m for the first, second and third passes of the experiment, respectively. The robot achieved an MAE of 0.06 m. When turning at the end of the row, the MAE from the RTK-GNSS-generated path was 0.24 m. The turning errors were acceptable for the open field at the end of the row. Errors while driving down the row did damage the plants by moving close to the plants’ stems, and these errors likely would not impede operations designed for the MPR. Therefore, the designed rover and control algorithms are good and can be used for cotton harvesting operations.
Center-articulated hydrostatic cotton harvesting Rover using visual-servoing control and a finite state machine
(MDPI, 2020-07-30) Kadeghe, Fue; Wesley, Porter; Edward, Barnes; Changying, Li; Glen, Rains
Multiple small rovers can repeatedly pick cotton as bolls begin to open until the end of the season. Several of these rovers can move between rows of cotton, and when bolls are detected, use a manipulator to pick the bolls. To develop such a multi-agent cotton-harvesting system, each cotton-harvesting rover would need to accomplish three motions: the rover must move forward/backward, turn left/right, and the robotic manipulator must move to harvest cotton bolls. Controlling these actions can involve several complex states and transitions. However, using the robot operating system (ROS)-independent finite state machine (SMACH), adaptive and optimal control can be achieved. SMACH provides task level capability for deploying multiple tasks to the rover and manipulator. In this study, a center-articulated hydrostatic cotton-harvesting rover, using a stereo camera to locate end-effector and pick cotton bolls, was developed. The robot harvested the bolls by using a 2D manipulator that moves linearly horizontally and vertically perpendicular to the direction of the rover’s movement. We demonstrate preliminary results in an environment simulating direct sunlight, as well as in an actual cotton field. This study contributes to cotton engineering by presenting a robotic system that operates in the real field. The designed robot demonstrates that it is possible to use a Cartesian manipulator for the robotic harvesting of cotton; however, to reach commercial viability, the speed of harvest and successful removal of bolls (Action Success Ratio (ASR)) must be improved.
Deep learning based Real-time GPU-accelerated tracking and counting of cotton bolls under field conditions using a moving camera
(2018 ASABE Annual International Meeting, 2018-08) Fue, Kadeghe G.; Porter, Wesley; Rains, Glen
Robotic harvesting involves navigation and environmental perception as first operations before harvesting of the bolls can commence. Navigation is the distance required for a harvester’s arm to reach the cotton boll while perception is the position of the boll relative to surrounding environment. These two operations give a 3D position of the cotton boll for picking and can only be achieved by detection and tracking of the cotton bolls in real-time. It means detection, tracking and counting of cotton bolls using a moving camera allows the robotic machine to harvest easily. GPU-accelerated deep neural networks were used to train the convolution networks for detection of cotton bolls. It was achieved by using pretrained tiny yolo weights and DarkFlow, a framework which translates YOLOv2 darknet neural networks to TensorFlow. A method to connect tracklets using vectors that are predicted using Lucas-Kanade algorithm and optimized using robust L-estimators and homography transformation is proposed. The system was tested in defoliated cotton plants during the spring of 2018. Using three video treatments, the counting performance accuracy was around 93% with standard deviation 6%. The system average processing speed was 21 fps in desktop computer and 3.9 fps in embedded system. Detection of the system achieved an accuracy and sensitivity of 93% while precision was 99.9% and F1 score was 1. The Tukey’s test showed that the system accuracy and sensitivity was the same when the plants were rearranged. This performance is crucial for real-time robot decisions that also measure yield while harvesting.
Design of the improved evaporative cooling structure for storage of tomatoes in morogoro
(Sokoine university of agriculture, 2022) Mwankemwa, Leonard Saimon
In most developing countries, smallholder farmers face several challenges while embarking on their farming for agriculture crop production. The challenges are serious during post-harvesting processes. The phenomenon is evident in sub-Saharan countries, Tanzania inclusive. Tanzania’s economy is agriculturally based which contributes 26.7% of its GDP and it employs over 80% of the population. As such any efforts geared to eradicate poverty and improve livelihoods should focus on the agriculture (horticulture subsector) which is characterized by small scale subsistent farming, low productivity, and huge post-harvest losses. These huge losses can be attributed to a lack of appropriate post- harvest processing techniques, low awareness, on the part of good harvesting and packaging practices or techniques and lack of storage facilities. Morogoro smallholder farmers of tomatoes are not spared from this phenomenon. Several storage technologies for curbing tomato post-harvest losses have been introduced to smallholder farmers. Some technologies have shown promising results. However, more investigation of the technology’s effectiveness is needed. This study aimed to design an evaporative cooling structure for the storage of tomatoes. A need assessment survey was conducted to help generate information on tomato handling practices and losses for small scale farmers and retailers in six selected areas in the Morogoro region. Sixty respondents with at least 3 years of farming or retailing tomatoes were purposively selected through the help of the extension officer and market leaders to represent part of the tomatoes’ handling chain. The findings obtained showed that farmers were not using any storage facilities for tomatoes while retailers used inferior handling facilities and some did not use any storage facilities, ultimately losing most of their tomatoes. This study found that tomato post-harvest losses (PHLs) were 29.7% at the farmers’ level and 18.4% at the small scale retailers’ level during handling and marketing. The majority of the respondents showed a desire to possess evaporative coolers to reduce tomato PHLs. In this context, the improved wind operated passive evaporative cooling (IWOPEC) storage structure for tomatoes was designed and fabricated, and its performance was evaluated against other storage conditions. A randomized complete block design (RCBD) was used. The storage environment conditions considered were ambient (AT), cold room (CR), and IWOPEC structure. The results on the effects of temperature and relative humidity (RH) were significantly different (p<0.05) under the studied storage environments. Total soluble solids and percentage weight loss significantly increased (p<0.05) for all studied environmental conditions, whereas firmness and titratable acid significantly decreased (p<0.05) in response to storage time and environmental conditions. The IWOPEC structure reduced temperature, increased RH and gave peak and daily average cooling efficiency of 84.89% and 61.67%, respectively. The result of the benefit-cost ratio (BCR) was 2.51 shows using the IWOPEC structure for the storage of fresh ripened tomatoes is viable. In areas with high PHLs under AT, using the IWOPEC structure to improve the shelf life of tomatoes is economically feasible. Improvement of the IWOPEC structure by having water boot sump and a water pump to increase the cooling efficiency of the storage atmosphere is recommended.
Development and performance evaluation of solar greenhouse dryer with desiccant energy storage system for tomatoes
(Sokoine University of Agriculture, 2021) Mbacho, Susan Andrew
Tomato is one of the most important horticultural crops widely grown in the tropical East Africa countries. It is mostly used as vegetable recipe for food preparation at most homes or consumed raw as a salad. However, during the rainy season, tomato farmers experience widespread post-harvest losses due to insect and molds infestation. Also, during harvesting seasons, most markets in East Africa are flooded with the produce leading to over- supply against low demand resulting to heavy postharvest losses. Therefore, it is necessary to use appropriate drying technologies especially solar drying technology to reduce these losses. The use of solar drying technology is a good alternative solution to the problem of crop drying and especially the perishable tomato crop. Literature review show that most solar crop drying technologies developed for the past 50 years have very small loading capacity and cannot operate during the night. Therefore, in this study, we developed an integrated greenhouse solar dryer with Clay- CaCl 2 solid desiccant energy storage system. Solar greenhouse drying systems have an advantage over other solar drying systems because its structural simplicity combined with high loading capacity. In addition, they have relatively good thermal crop drying performance compared to most solar dryers. The system was tested under no-load and load conditions. The experimental study with no-load condition exhibited the mean collector temperature of 41.9 °C giving an average temperature rise of 14.7 °C (35%) above the ambient (27.2 °C) with an average R.H. value of 32.6% at the flow rate of 0.28 m 3 /s on the test date. When the desiccant energy storage was used during night an average greenhouse temperature recorded within the drying chamber was 26.5 °C higher than the ambient temperature of 15.9 °C (40 % temperature rise). The results obtained under desiccant energy storage showed that at a 0.07 m 3 /s air flow rate with an average rise in temperature of about 13.6 (32.3%) against the average ambient temperature of 28.5°C. The average relative humidity within the system was found to be 36.5% lower than the ambient R.H. (84.1%). The collector efficiencies obtained from no load test was 46.2% and 40.8% for the dryer and desiccant chamber respectively. The performance of the dryer was evaluated with fresh tomato load during the month of September - December 2019 at Kenyatta University field site. The dryer demonstrated capacity to dry fresh tomatoes from 93.9% (wb) to 8.3% (wb) within 27 hours with solar greenhouse drying efficiency of 23% while at night the dryer demonstrated desiccant drying efficient of 19.9%. The drying rate for the two-day solar drying was 0.985 kg/h and 0.875 kg/h respectively and that in night drying using desiccants was 0.34 kg/h. The economic analysis of the drying system shows a payback period of less than a year (0.54 year) with benefit-cost ratio of 8.4 implying that the system is economically viable. On the basis of these results, it was concluded that prototype solar greenhouse dryer with Clay-CaCl 2 energy storage system has great potential for tomato drying and other high moisture agricultural products in East African countries.
Evaluating the effect of planter downforce and seed vigor on crop emergence and yield in Hill-drop vs Singulated Cotton.
(2018 Beltwide Cotton Conferences, San Antonio, 2018-01) Virk, S. S.; Porter, W. M.; Fue, K. G.; Snider, J. L.; Whitaker, J.
Selection of correct planting parameters and their optimization based on current field conditions is crucial in achieving high crop emergence, which can translate to higher yields. A study was conducted during 2017 to evaluate the effect of planter downforce and seed vigor on crop emergence and yield in two cotton varieties planted with singulated and hill-drop seed plates. For this study, two cotton varieties (a small seeded low vigor variety and a large seeded high vigor variety) were planted at 1-inch seeding depth using two different planters to obtain singulated and hill-drop planting conditions. Two seeding rates of 29,000 seeds/ac and 42,500 seeds/ac were used to represent a typical low and high population for planting cotton in Georgia. Planter downforce treatments consisting of low, medium and high downforce values (100, 200 and 300 lbs., respectively) were implemented using the available downforce technology on both planters. Field data collection consisted of emergence counts at one and three weeks after planting and yield data from the center two rows of a four row plot at the end of the season. Data analysis indicated that singulated seeds were more effective in low downforce treatments independent of the crop variety. Hill-drop seeds exhibited better crop emergence (75-81%) in higher downforce treatments as compared to crop emergence (62-72%) obtained with singulated seeds. Yield data also suggested that singulated cotton can maximize emergence in low to medium downforce conditions for large seeded high vigor varieties whereas hill-drop cotton yields better with small seeded low vigor varieties planted at medium to high downforce. Results showed that low vigor varieties require higher seeding rates (more seeds per foot) when planted using low downforce to provide an overall high crop emergence rate whereas this trend was not observed in the high vigor variety. A comparison among seeding rates showed that higher seeding rates did not maximize crop emergence when planted as hill-drop. Overall results from this study emphasized the importance of using correct planting parameters (downforce, seeding rate, and variety) based on existing field conditions to maximize crop emergence and yield.
Evaluation of a stereo vision system for cotton row detection and boll location estimation in direct sunlight
(MDPI, 2020-08-05) Kadeghe, Fue; Wesley, Porter; Edward, Barnes; Changying, Li; Glen, Rains
Cotton harvesting is performed by using expensive combine harvesters which makes it difficult for small to medium-size cotton farmers to grow cotton economically. Advances in robotics have provided an opportunity to harvest cotton using small and robust autonomous rovers that can be deployed in the field as a “swarm” of harvesters, with each harvester responsible for a small hectarage. However, rovers need high-performance navigation to obtain the necessary precision for harvesting. Current precision harvesting systems depend heavily on Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS) to navigate rows of crops. However, GNSS cannot be the only method used to navigate the farm because for robots to work as a coordinated multiagent unit on the same farm because they also require visual systems to navigate, avoid collisions, and to accommodate plant growth and canopy changes. Hence, the optical system remains to be a complementary method for increasing the efficiency of the GNSS. In this study, visual detection of cotton rows and bolls was developed, demonstrated, and evaluated. A pixel-based algorithm was used to calculate and determine the upper and lower part of the canopy of the cotton rows by assuming the normal distribution of the high and low depth pixels. The left and right rows were detected by using perspective transformation and pixel-based sliding window algorithms. Then, the system determined the Bayesian score of the detection and calculated the center of the rows for the smooth navigation of the rover. This visual system achieved an accuracy of 92.3% and an F1 score of 0.951 for the detection of cotton rows. Furthermore, the same stereo vision system was used to detect the location of the cotton bolls. A comparison of the cotton bolls’ distances above the ground to the manual measurements showed that the system achieved an average R2 value of 99% with a root mean square error (RMSE) of 9 mm when stationary and 95% with an RMSE of 34 mm when moving at approximately 0.64 km/h. The rover might have needed to stop several times to improve its detection accuracy or move more slowly. Therefore, the accuracy obtained in row detection and boll location estimation is favorable for use in a cotton harvesting robotic system. Future research should involve testing of the models in a large farm with undefoliated plants.
An extensive review of mobile agricultural robotics for field operations: focus on cotton harvesting
(MDPI, 2020-03-04) Kadeghe, G. Fue; Barnes, Edward M.; Rains, Glen C; Porter, Wesley M
In this review, we examine opportunities and challenges for 21st-century robotic agricultural cotton harvesting research and commercial development. The paper reviews opportunities present in the agricultural robotics industry, and a detailed analysis is conducted for the cotton harvesting robot industry. The review is divided into four sections: (1) general agricultural robotic operations, where we check the current robotic technologies in agriculture; (2) opportunities and advances in related robotic harvesting fields, which is focused on investigating robotic harvesting technologies; (3) status and progress in cotton harvesting robot research, which concentrates on the current research and technology development in cotton harvesting robots; and (4) challenges in commercial deployment of agricultural robots, where challenges to commercializing and using these robots are reviewed. Conclusions are drawn about cotton harvesting robot research and the potential of multipurpose robotic operations in general. The development of multipurpose robots that can do multiple operations on different crops to increase the value of the robots is discussed. In each of the sections except the conclusion, the analysis is divided into four robotic system categories; mobility and steering, sensing and localization, path planning, and robotic manipulation.
Field testing of the autonomous cotton harvesting Roverin undefoliated cotton field
(2020 Beltwide Cotton Conferences, Austin, Texas, 2020) Fue, K. G.; Porter, W. M.; Tifton, G. A.; Barnes, E. M.; Cary, N. C.; Rains, G. C.
This study proposes the use of an autonomous rover to harvest cotton bolls before defoliation and as the bolls open. This would expand the harvest window to up to 50 days and make cotton production more profitable for farmers by picking cotton before the quality is at risk. We developed a cotton harvesting rover that is a center-articulated vehicle with an x- y picking manipulator and a combination vacuum and rotating tines end-effector to pull bolls off the plant. The rover uses a stereo camera to see rows, RTK-GPS to localize itself, fisheye camera for heading, and stereo camera to locate the cotton bolls. The SMACH library is a ROS-independent task-level architecture used to build state machines for the rapid implementation of the robot behavior. First, the GPS waypoints are obtained, and then, the rover passes over the rows while picking the cotton bolls. The navigation is controlled by a modified pure-pursuit technique together with a PID controller. Two parallel programs organize the entire rover regarding when to pick and when to navigate. While navigating, the rover looks for harvestable bolls, and when bolls are discovered, the robot will stop and pick. It will do this repetitive work until it finishes all the rows. The rover navigation had an absolute error mean of 0.189 m, a median of 0.172 m, a standard deviation of 0.137 m, and a maximum of 0.986 m. The largest errors occurred during turning around at the end of rows and were caused by wet conditions and tire slippage. The rover picked cotton bolls at the average Action Success Ratio (ASR) of 78.5% and was able to reach 95% of the bolls. Most bolls that were not picked could not be pulled into the vacuum using the rotating tines on the end-effector.
Irrigation performance of a water distribution system: The case of Kigugu irrigation scheme-Mvomero district Morogoro region Tanzania
(Science publishing group, 2024) Chogohe, Mnega Hussein; Silungwe, Festo Richard; Tarimo, Andrew Kirumi Paul Rai
This study assessed the performance of the Kigugu Irrigation Scheme's water distribution system in Tanzania with an emphasis on its impact on crop yields. We used a combination of participatory tools and direct observation to gather comprehensive data, including weather patterns, water discharge rates, and farmer input levels. Descriptive statistical analysis revealed significant variations in water distribution across canals, with Relative Water Supply (RWS) values ranging from 0.7 to 5.9, indicating instances of both over- and under-supply. Despite these variations, satisfactory performance was demonstrated by the irrigation system, with high Water Delivery Performance Ratio (WDPR) values consistently recorded above 0.65, indicating that water demands were largely met across the system. Furthermore, the study found that equity in water distribution improved significantly during the growing season, with the equity index dropping from 0.2 to 0.1. This underscores the critical need for fair water allocation practices, particularly during low-flow periods, to ensure that all farmers receive an adequate supply. Based on these findings, several recommendations for irrigation system modifications were proposed to further improve water distribution and equity. In terms of productivity, a notable correlation between water distribution and crop yield was observed. A canal with a design discharge of 0.0228 m 2 /s produced a yield of 552.18 metric tonnes, demonstrating efficient water utilization. In contrast, canal SC.4-2, with a lower discharge of 0.0185 m2/s, achieved a smaller yield of 274.31 metric tonnes, further highlighting the importance of optimal water distribution for enhancing agricultural productivity. Overall, the Kigugu Irrigation Scheme maintains a reliable water supply, contributing positively to sustainable water resource management and agricultural productivity. This, in turn, supports local economic growth, enhances food security, and improves community well-being. The study’s findings provide critical insights for future improvements in irrigation management and resource allocation
Irrigation scheduling
(Sokoine University of Agriculture, 1984) Thadei, Simon y
This thesis deals with irrigation scheduling under rotational water supply. First, irrigation scheduling is defined and the general review of the principles, factors, methods, and scheduling techniques which must be considered before scheduling is given. This includes crop water requirements, factors affecting crop water requirements and methods for determining crop water requirements. Then soil waterholding capacity, irrigation requirements (efficiencies and leaching requirements), amount of water for irrigation, availability of water supply, and scheduling techniques are reviewed. Also, Tanzania's case study is given for two projects: Mbarali (a state farm) and Mombo (village owned farm). Finally, irrigation schedule is prepared for Mombo irrigation scheme.
Likelihood of adopting briquette technology in abundance of competitive energy sources: a case study of Morogoro urban and rural districts, Tanzania
(Research Gate, 2022) Yustas, Y. M.; Tarimo, W. M.; Mbacho, S. A.; Kiobia, D. O.; Makange, N. R.; Kashaija, A. T.; Silungwe, F. R.
Firewood and charcoal are the primary energy resources in many developing countries, especially in sub-Saharan Africa. However, the unstainable collection and use of these resources negatively impact the environment. Equally, using briquettes as green energy resources can address the energy shortage and conserves the environment. However, the information on people’s preference to use briquettes instead of other alternative energy sources is scarce. Furthermore, studies demonstrating the briquette technology preferences and adoption to prospective users, including youth and women in urban and rural areas, are limited. Therefore, this study was conducted in the Morogoro district to (1) characterise the respondents’ demographic issues useful for evaluation of people's preferences, (2) assess the preference for briquette fuels, particularly for youth and women, and (3) evaluate the extent of using the briquettes as sources of energy as compared to other alternative sources of energy. The household survey involved 330 respondents in urban, peri-urban, and rural areas of Morogoro. The areas were chosen to represent the Tanzania sceneries. Besides, supplementary key informants’ interviews involved village leaders, charcoal retailers and other people with knowledge of briquette technology. The results show that over 95% of respondents preferred to use briquette as an alternative energy source and expressed their willingness to engage in the briquette business. Additionally, the study shows low use of briquettes compared to other energy sources like charcoal and firewood in urban, peri-urban, and rural areas.Furthermore, there was no significant difference between men and women in their willingness to join the briquette business (p-value =0.517). Therefore, a few people are aware of briquette technology. This study recommends increasing the awareness of briquette technology through training youths and women on briquette technology and insisting on the availability of briquette products and stoves. In addition, assessing the factors hindering the briquettes from being a hundred per cent preferred by people is a point of research interest.
Mechanisms of mechanical oil expression from rapeseed and cashew.
(University College Dublin, 1979-02) Mrema, Geoffrey C.
The conventional theory of oil expression from vegetable oilseeds suggests that before substantial oil expression can occur, the oilseed cellwalls have to be ruptured by a combination of physical (crushing) and thermal (cooking) pre-treatments. Results from oil expression tests using rapeseed and cashew on the Instron Universal Testing Machine have suggested an alternative mechanism in which up to 80% oil is expressed through a porous cellular microstructure under pressure without cellwall rupture and at ambient temperature. The porous mission electron microscopy. The cellwall pores (plasmodesmata) were of diameter 0.87 and 0.126 pm wall surface area for rapeseed and cashew respectively. The oil expression process has been successfully described by a mathematical model based on three modified form of Terr.aghi's equation for the consolidation of saturated soils., to describe the behaviour of the consolidating oilseed cakej the Hagen Poiseulle equation for flow of fluids to describe the flow of oil through the pores on the cellwall; and The model has Darcy 's law of flow of fluids through porous media to describe the flow of oil through the intra-kernel voids. in pipes, fundamental equations: a oil expression can occur, the oilseed cellwalls and average porosity of 0.093 and 0.171% of the cellnature of the cellwalls has been confirmed by trans been succeafully applied to experimental data which has revealed that the flow of oil across cellwalls in the seed kernel was the rate determining step. In addition the model was also used to analyse the performance of hydraulic and screw expellers. The study has suggested that the design of both hydraulic and screw expellers could be improved by incorporating an undrained compression pretreatment to rupture cellwalls 3 and by reducing the drainage area to 0.5% - 1.5%. Furthermore^ improved strategies for oil expression have been suggested in two cases, (a) For mechanical expression followed by solvent extraction it is proposed that the physical (pre-crushing) and thermal (cooking) pre-treatments be replaced by an undrained compression pre-treatment. are not r equired (b) where mechanical expression is the sole process^ the pre-crushing pre-treatment should replaced by an undrained compression pre-treatment.
Modelling the water balance of a small catchment: a case study of Muhu catchment in Southern highlands of Tanzania
(Sokoine University of Agriculture, 2000) T. Shiba, Sipho Simeon S.
I'he water balance ol'Muhu catchment located in the Southern Highlands of Tanzania in Iringa region was modelled by establishing the empirical relations that exist between storage parameters, rainfall parameters and runoff components. Storage parameters included soil moisture storage and interception. Rainfall parameters included rainfall amount, intensity, duration. throughfalL stemflow and evaporation. Runoff components included total runoff, direct runoff and base How. The catchment's physical and hydrological characteristics that affect these parameters were determined. 1 he assessment of hydrological and physical properties showed that the soils were predominantly sandy clay, having high organic matter content, with a moderately rapid hydraulic conductivity (Ks) of 4.2 cm/h and infiltration rale of 3.8 cm/ h. The bulk density was generally low with an average of 0.9 g/cnT for 0-15 cm depth: 1.1 Ig/cm5 for 15-30 cm depth and 1.30 g/cm’ for 30 - 45 cm depth. The catchment had a slope steepness of 35 % and a varying vegetal percentage cover of about 56 %. The 1997/98 waler year was exceptional with high rainfall (1934 mm) mainly due to the El-nino phenomenon. Sixty-seven percent of the rainfall received in the catchment penetrated the canopy to reach the forest floor as throughfalL On average 3.3 % of the rainfall reached the forest floor as stem flow' while 25.5% of the rainfall was intercepted by the canopy. ThroughfalL stemflow and interception were linearlyIll related to rainfall. Die regression coefficients of all the relationships were significantly different from zero al 1% level (fteO). With increasing percentage surface cover, interception increased while throughfall decreased. The storage capacity of the forest cover was estimated to be 0.7 mm. Il has been found in this study that stream flow and runoff have gradually been increasing since the 1994/95 season. However the rainfall trend docs not support this development. A consideration of runoff curve numbers showed that the observed trend was partly due to catchment degradation, farming activities in the area have gradually been substituting the forest with arable land, thus reducing surface cover. Records indicated that the lowest recorded daily mean How was 0.27 m'/s. while the highest was 1.6 m'/s. I he water balance was positive during the first five months of the wet season. The highest water balance was in April. During this period there was more recharge to the soil moisture and ground water storage. Water balance was negative in the remaining seven months of the water year, with the lowest in September. The developed direct runoff model and water balance model were found to be valid and useful in estimating the respective parameters in forested catchments of the southern highlands of Tanzania.
Performance evaluation of an indigenous irrigation system at towero village, western Uluguru mountains, Tanzania
(Sokoine University of Agriculture, 2000) Kongola, Malongo John Mussa
Indigenous irrigation methods in mountainous areas are a result of people’s efforts to survive on limited land resource bases. The adoption of an irrigation method depends on whether it does not affect the soil. While surface methods are common in the Uluguru Mountains, drag hose sprinkling is receiving wide use at Towero. Drag hose sprinkler irrigation refers to the local use of sprinklers where water pressure is obtained by gravity flow. Effects of indigenous irrigation systems’ practices on soil erosion were evaluated using field data and aerial photographs. Field data were obtained from six slopes, ranging from 6 to 84%. Two versions of aerial photographs were used to produce land-use maps for 1964 and 1992, respectively. Traversing produced the land-use map of 1999. Land-use analysis revealed that between 1964 and 1999, the area under indigenous irrigation increased by 0.81 ha/ycar. Between 1964 and 1999 the settlement area increased by 0.83 ha/year. Deforestation rate was 6.48 ha/year. Mean crop yields for leeks ranged between 9.65 — 13.53 tonne/ha. Mean specific yields ranged between 0.65 - 1.09 kg/m3. Mean water conveyance, application and storage efficiencies were 83.72%, 86.20% and 99.64%, respectively. All fields wereii over-irrigated based on soil moisture data which were taken daily. Over-irrigation caused inequitable water distribution. Daily sediment load transport in canals A, B and C were 22.2 kg, 187.6 kg and 54.7 kg, respectively. Total sediment loss was 264.6 kg per day. Net downslope splash loss at 84, 70, 65, 24 and 15% slope was 28.9, 19.1, 12.0, 6.0, and 1.0 kg/ha, respectively. The effects of indigenous irrigation systems’ practices at Towero were: soil loss in the form of splash erosion and sediment load transport, and acceleration of deforestation in pursuit for more agricultural land. Hence, efforts to promote soil conservation practices at Towero are essential.
Real-time 3-D measurement of cotton boll positions using machine vision under field conditions
(2018 Beltwide Cotton Conferences, San Antonio, 2018-01) Fue, K. G.; Rains, G. C.; Porter, W. M.; Tifton, G. A.
Cotton harvesting is performed by expensive combine harvesters that hinder small to medium-size cotton farmers Advances in robotics provide an opportunity to harvest cotton using small and robust autonomous rovers that can be deployed in the field as an “army” of harvesters. This paradigm shift in cotton harvesting requires high accuracy 3D measurement of the cotton boll position under field conditions. This in-field high throughput phenotyping of cotton boll position includes real-time image acquisition, depth processing, color segmentation, features extraction and determination of cotton boll position. In this study, a 3D camera system was mounted on a research rover at 82° below the horizontal and took 720p images at the rate of 15 frames per second while the rover was moving over 2-rows of potted defoliated cotton plants. The software development kit provided by the camera manufacturer was installed and used to process and provide a disparity map of cotton bolls. The system was installed with the Robot Operating System (ROS) to provide live image frames to client computers wirelessly and in real time. Cotton boll distances from the ground were determined using a 4-step machine vision algorithm (depth processing, color segmentation, feature extraction and frame matching for position determination). The 3D camera used provided distance of the boll from the left lens and algorithms were developed to provide vertical distance from the ground and horizontal distance from the rover. Comparing the cotton boll distance above the ground with manual measurements, the system achieved an average R2 value of 99% with 9 mm RMSE when stationary and 95% with 34 mm RMSE when moving at approximately 0.64 km/h. This level of accuracy is favourable for proceeding to the next step of simultaneous localization and mapping of cotton bolls and robotic harvesting.
Repair costs of tractors and comparison of mechanization strategies under Tanzanian conditions
(University of Munich, 2000-08) Mpanduji, Sylvester Michael

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