Profiling Agricultural Engineering Technologies for Mechanizing Smallholder Agriculture in Uganda

Developing countries are grappling with numerous challenges including feeding rapidly growing populations, alleviating poverty, protecting the environment and mitigating adverse impacts of climate change. For the coming years, one of the main agricultural development agenda for Sub-Saharan Africa (SSA) should be to increase agricultural productivity and production to achieve food security through agricultural mechanization with Agricultural Engineering Technologies (AETs) as major inputs. However, there is paucity of information on the status of existing AETs and their contribution to mechanizing smallholder agriculture which is crucial to effective planning and strategy formulation. Therefore, the overarching objective of this paper is to review past and present status, constraints to adoption and future of AETs in Uganda in the context of mechanizing smallholder agriculture. Several proven AETs developed through research institutions and universities have been profiled in different areas of farm power and mechanization systems, agro-processing for value addition; renewable energy systems; water harnessing and utilization and other emerging agricultural engineering fields. The future of AETs in Uganda is hinged on the interaction of AETs with key drivers that include policy, social, cultural, economic, environmental, vocational skills development, innovation protection, research and institutional partnerships.

A critical review of selected appropriate traditional evaporative cooling as postharvest technologies in Eastern Africa

The issue of postharvest losses (PHL) is of high importance in the efforts to combat hunger, raise income and improve food security in the world’s poorest countries. PHL of horticultural products in developing countries sometimes may reach up to 45%. PHL have an impact on food security for poor people, food quality and safety, economic development and the environment. The exact causes of PHL vary throughout the world and are very much dependent on the specific conditions and local situation in a given country. Irrespective of the level of economic development and maturity of systems in a country, PHL should be kept to a minimum. PHL of horticultural products in developing countries sometimes may reach up to 45%. The failure to harness the physical and chemical characteristics of horticultural products using technologies has been very costly to farmers, processors and marketers in many parts of the world. A number of researchers and undocumented indigenous African Knowledge custodians in rural areas have innovated and constructed different technologies using locally available materials for the purpose of extending the shelf life of horticultural produce like vegetables. This review article seeks to critically examine some of the selected agricultural technologies and equipment used in African rural settings with view of assessing why they fail

Solar Fruit Drying Technologies for small holder farmers in Uganda. A Review of Design Constraints and Solutions

Solar fruit drying is a technology that is successfully applied on both domestic and commercial scale among smallholder farmers in Uganda. However, existing solar drying technologies are marred with multiple deficiencies such as inefficient conversion of trapped solar radiation to meet required enthalpy, low throughput, long drying times, and inherent difficulty to achieve acceptable hygiene among others. This review examines existing solar drying technologies in Uganda, highlighting design constraints and plausible solutions for supporting the growing fruit drying industry. The common types of solar driers in Uganda are the static-bed box type solar dryer model, the PPI tunnel solar dryer model, the NRI Kawanda cabinet solar dryer, the hybrid tunnel solar dryer and the UNIDO solar hybrid dryer model. Findings reveal that the challenges characterizing existing dryers in perspective of design are attributed to; poor material selection, poor mass and energy transfers, total dependence on solar energy, lack of capacity by local craftsmen to replicate new and improved models, difficulty to clean the dryers caused by inapt model configurations, and high cost of installation to mention a few. Therefore, a need exists to develop efficient and affordable designs using scientifically proven methods such as Computer Fluid Dynamics to pre-test and optimize the driers, incorporating alternative energy sources in the design to ensure an all-weather dryer. Additionally, disseminate such innovations to farmers, retool local artisans with quality fabrication skill sets, and develop simple manual with standards and fabrication procedures for the fruit driers

Automation and control system implementation in a smallholder crop production in Uganda: A review

This review paper explores the potential of automation and control systems in addressing critical challenges faced by agriculture in developing countries, with a specific focus on their applicability in Uganda. The study aims to comprehensively evaluate the role of these systems in enhancing agricultural practices, including the identification of adoption challenges, assessment of potential benefits, investigation of system effectiveness, and provision of evidence-based recommendations. The findings reveal that while there are notable obstacles such as high initial costs, limited technical expertise, and database constraints, there are also substantial opportunities, particularly through the integration of supportive information and communication technology (ICT) strategies and policies. Automation has demonstrated its effectiveness in various agricultural tasks, from mechanized tractors to food processing and livestock farming, offering promising prospects for value addition, irrigation, hydroponics, aquaponics, greenhouse farming, and livestock management. Despite the current modest adoption rates, the study provides compelling evidence supporting the need for increased utilization of automation and control systems in Uganda’s agriculture. Collaboration among stakeholders, formulation of supportive policies, development of comprehensive databases, prioritization of tailored ICT infrastructure, and facilitation of knowledge sharing are recommended to overcome challenges and harness the transformative capability of automation. In conclusion, embracing automation holds the key to enhancing the sustainability and food security of Uganda’s agriculture, offering valuable insights for policymakers and stakeholders in guiding the sector’s future advancement

Rainwater harvesting knowledge and practice for agricultural production in a changing climate: A review from Uganda’s perspective

With a changing climate in Uganda, rainfall distribution patterns have become more irregular over time and space. Excess water during rainy season is causing runoff, soil erosion, nutrient depletion and crop damage which reduce the productive capacity of land, while on the other hand, prolonged droughts during the crop growing period have become common occurrences. Additionally, pastoralists lose livestock during the dry period each year in the Cattle Corridor of Uganda due to water shortage and lack of forage. It thus remains difficult to achieve the agricultural development targets identified in the National Development Plan for Uganda, without addressing regular incidences of adverse impacts of climate change. Currently there are no well explained approaches which can contribute to adoption of technologies like rainwater management systems which are crucial in enhancing crop yields and livestock production during periods of water shortage. The overarching objective of this paper was to carry out an assessment of the status, performance, and scope for improving rainwater harvesting (RWH) for small-scale agriculture under local conditions. Accordingly, research gaps in RWH technologies were identified and documented to inform future studies. The research was carried out in the semi-arid areas of Nakasongola, Rakai, and Hoima Districts characterized by crop-livestock dependent livelihoods. Findings show that RWH Technologies can enable smallholder farmers and agro-pastoralists to become more resilient to increasing climate variability and climate change by conserving soil and water thus increasing food production and enhancing food security. Small-scale irrigation systems have enabled farmers adapt to drought challenges by enhancing crop yields and allowing farmers to target for higher market prices usually associated with the effects of drought. However, there are challenges including threats to sustainability of such established systems because of lack of community participation in systems’ monitoring and maintenances, and vandalism, and some systems require high investment costs.

Modeling sludge accumulation rates in lined pit latrines in slum areas of Kampala City, Uganda

Disposal of faecal sludge particularly in slum areas is a difficult undertaking given the lack of space and resources. Inaccurate prediction of sludge accumulation rates (SAR) in pit latrines leads to unplanned pit latrine emptying. Given that the users and owners cannot afford the conventional emptying techniques frequently, inappropriate methods such as open defecation and emptying into storm drainages are employed which consequently contribute to environmental and health-related challenges. The main objective of this study was to develop a predictive model for sludge accumulation rates in lined pit latrines in slum areas of Kampala so as to guide routine management of pit latrines. This mathematical model was developed using a mass balance approach with a sample space of 55 lined pits. The developed model gave an average sludge accumulation rate of 81±25 litres/person/year with an efficiency of 0.52 and adjusted R2 value of 0.50. The model was found to be sufficient and most suited for rental and public pit latrines given their bigger percentage in the slums. Further studies should include geo-physical characterization of soil and drainage of pit latrine sites so as to improve model accuracy.Keywords: Faecal, sludge accumulation rates, slum areas, lined pit latrine

Transforming Corn Stover to Useful Transport Fuel Blends in Resource-Limited Settings

Development of local technologies is crucial to the sustainable energy agenda in resource-limited countries and the world. Strengthening local green technologies and promoting local utilization will reduce carbon emissions that could be generated during transportation and delivery of green products from one country to another. In this paper we developed bio-oil/diesel blends using a low-tech pyrolysis system designed for smallholder farmers in developing countries and tested their appropriateness for diesel engines using standard ASTM methods. Corn stover retrieved from smallholder farmers in Gayaza, Uganda were pyrolyzed in a batch rocket stove reactor at 350 °C and liquid bio-oil harvested. Bio-oil chemical composition was analyzed by Gas Chromatography equipped with Flame Ionization Detector (GC-FID). Bio-oil/diesel emulsions in ternary concentrations 5%, 10% and 20% bio-oil weight were developed with 1% concentration of sorbitan monolaurate as an emulsifier. The bio-oil/diesel emulsions and distillates had property ranges: specific gravities at 15 °C 827.4–830.7 kg m−3, specific gravities at 20 °C 823.9–827.2 kg m−3, kinematic viscosities at 40 °C 3.01–3.22 mm2/s, initial boiling points 140–160 °C, final boiling points 354–368 °C, and calculated cetane indexes 56.80–57.63. These properties of the bio-oil/diesel blends and their distillates compare well with standard transportation diesel fuel. The emulsion distillates meet the standard requirements for automotive diesel in East Africa

Contextual investigation of factors affecting sludge accumulation rates in lined pit latrines within Kampala slum areas, Uganda

Pit latrines in slums areas of Uganda fill up faster than might be expected from some estimates owing to inappropriate use and failure to consider critical factors affecting sludge accumulation rates at the planning, design and construction stages. This study sought to investigate factors affecting filling rates of lined pit latrines in slum areas of Kampala with the goal of contributing to accurate planning, design, construction, emptying and overall maintenance. Fifty-five pit latrines were selected from the five divisions of Kampala city using stratified random sampling. Data collected included: number of users, frequency of emptying, years taken since last emptying, type of non-faecal materials deposited, cross-sectional dimensions of the pit, rate of sludge degradation and geo-physical factors of pit location. Methods used were: field surveys, questionnaires and key informant interviews plus on-site depth measurement. Mass loss tests to investigate the rate of sludge degradation were carried out in the laboratory at moisture content levels similar to those in pit latrines. Sludge accumulation rates were calculated using volume of sludge in the pit, number of users and time taken since last emptying. Statistical analyses included correlation and one-way ANOVA. Results revealed that number of users and type of material deposited in the pit latrines, especially non-faecal matter, had a significant (p < 0.05) effect on sludge accumulation rate. Public pit latrines with a higher number of users had lower sludge accumulation rates and this was attributed to greater degradation taking place and greater restriction on entry of non-faecal matter. The rate of sludge degradation was higher at 90–100% than 80–90% moisture content, due to better degradation conditions. Tighter restrictions on non-faecal material deposition into pit latrines are recommended to reduce filling rates of pit latrines in slum areas.Keywords: sludge accumulation rates, slum areas, faecal matter, degradation, lined pit latrine

Improving Maize Shelling Operation Using Motorized Mobile Shellers: <em>A Step towards Reducing Postharvest Losses in Low Developing Countries</em>

Maize shelling is still a challenge in low developing countries with more efforts required to advance this operation. In Uganda, motorized immobile maize shellers have been fabricated locally to enhance the shelling operation. However, their performance has not elated the farmers. The unsatisfactory performance is a result of these shellers being fabricated by local artisan with finite understanding of the maize grain characteristics and operation factors to optimize maize shelling. In addition, farmers in these countries have a deficiency of power to operate the motorized maize shellers available. Transportation of these motorized maize shellers is also still a challenge and it imposes an extra cost to the farmers hence reducing their profits from maize growing. In this chapter, we reviewed maize shelling process in low developing countries particularly the categories of maize shelling, maize sheller design requirements, use of equations to design sheller parts, modification of the motorized maize shellers and case studies on the mobile maize shellers, comparing them with immobile maize shellers. The study concluded that on addition to other sheller performance attributes, motorized mobile maize shellers can solve transportation challenges associated with motorized immobile maize shellers