Degree Type

Dissertation

Date of Award

2018

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

Major

Sustainable Agriculture; Biorenewable Resources and Technology

First Advisor

Robert E. Mazur

Second Advisor

Thomas Brumm

Abstract

In Uganda, energy and food security are declining. Both depend on biomass in its traditional forms of charcoal and firewood for cooking and heating. With a fast growing population and increasing energy demand, biomass resources have been declining. This dissertation examined energy and food security in relation to biomass scarcity, crop production, and agricultural residue use. This work employed qualitative and quantitative analysis with primary data collected through semi-structured interviews with smallholder farmers and soil sampling from 2015 to 2016 in south-central Uganda.

In the first paper, this study estimated electricity potential from agricultural residues using the performance of the existing gasification technology in Uganda. Electricity estimates were developed for technical potential and wasted residues potential. Results suggest that electricity from wasted residues could be as much as an additional 70% of the current power capacity while the technical electricity potential could increase the current capacity more than threefold. The biorenewable energy potential has been untapped due to cost, cultural and information barriers, and weak policy frameworks that do not protect private investors from the risks associated with rural development projects. To address these issues, the government could reinstate the expired Renewable Energy Policy that sought to create adequate financing mechanisms, promote awareness of public benefits from biorenewable energy, and improve information on renewable resource availability.

In the second paper, food security was examined in relation to socioeconomic status, crop production, and soil quality determinants at household level using logistic regression. Total acreage and yields of banana and beans were positively associated with food security in the season of plenty. In the season of scarcity, total acreage, yields of maize and beans were positively associated with food security, while off-farm income was associated with less food security. The results indicate that land size and crop yields are more important to household food security than soil quality and socioeconomic status. While the issue of declining crop yields has been partially addressed through various banana breeding initiatives, the issue of land size is more problematic. Current land policies focus on strengthening land rights, which is important for investing in production technologies and soil conservation methods, but do not provide solutions for increasing land fragmentation. The issue of land fragmentation will require complex policy formulations that address historic, ethnic, demographic, and political aspects.

Third, soil quality and fertility were examined across cropping systems and soil types. Soil quality (pH at depths of 0 to 10 cm and 20 to 30 cm, CEC, and EC) and fertility (Ca and Mg) varied by cropping system. Annual rotation and banana systems were positively associated with better soil quality and fertility compared to other cropping systems. Soil quality (pH at depths of 0 to 10 cm and 0 to 15 cm and depth to restrictive layer) and soil fertility (P and K) varied by soil types. Black and black-stony soils were positively associated with soil quality and fertility compared to red soils. The results of this study indicate that both cropping system and soil type influence soil quality and fertility. What remains uncertain is the role of farmer decision making in specific cropping systems in certain soil types.

Finally, energy and food security were jointly analyzed in the context of biomass scarcity. The analysis evaluated temporal trends (2004-2014) in energy and food security as well as their associations with biomass availability. Energy and food security have declined, with energy security experiencing the biggest decline. Analyses showed a significant association between energy security and biomass availability, which indicates that energy consumption in Uganda is still highly dependent on biomass resources. Policies should focus more on fuel diversification and improved energy access rather than on leapfrogging to advanced energy types. Energy and food security policies should be evaluated jointly, since decisions on household energy, food production and consumption are inseparable. Therefore, energy production could be linked to Uganda’s plan for agricultural modernization which could lead to a more optimal allocation of resources and improved economic efficiency.

Copyright Owner

Nataliya Apanovich

Language

en

File Format

application/pdf

File Size

166 pages

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