Fostering Sustainability Through Organic Waste Re-Use in Sub Saharan Africa

Efficient re-use of organic wastes is of critical importance to the productivity of small-holder farm households in many parts of Sub-Saharan Africa (Smith et al., 2015). Organic wastes can provide important and sustainable organic fertilisers that recycle valuable nutrients back to the soil as well as increasing the organic matter content of the soil. This can improve soil structure, nutrient supply and productivity. Organic wastes are also widely used as sources of household fuel, usually by burning (dung or crop residues). Crop residues may also provide an important source of animal feed, while both dung and crop residues are used in building.

Technologies exist that allow more efficient use of organic wastes, so that they can be used to provide multiple functions and foster both sustainable food production and energy provision for smallholders farmers. For example, anaerobic digestion produces a much cleaner source of energy (biogas) than direct burning of organic wastes, while the residue from the process (bio slurry) is an excellent organic fertiliser, high in plant available nitrogen; pyrolysis cookstoves can be used to burn crop residues with much lower emissions of harmful particulates, with direct health benefit, especially for woman and children (see Thakur et al., 2018 for a review), while also producing biochar, which can either be incorporated in the soil as a soil improver, or briquetted to provide additional fuel (Smith et al., 2014).

However, despite the potential benefits of these technologies, adoption is slow. This may be due to
1. Unclear or non-realised benefits;
2. Lack of access to affordable equipment in remote areas;
3. Failures in the market for equipment and communication of benefits to potential users;
4. Preferences and cultural norms.

This project will examine:
1. the benefits of different technologies for more efficient use of organic wastes, producing maps of potential benefits in different areas of Sub-Saharan Africa,
2. the potentials for adoption, benefits and threats across different production systems and dominant value chains.
3. the factors influencing adoption or disadoption of different technologies in different regions of Sub-Saharan Africa,
4. failures in the market and communication of benefits to potential users.
The student will gain training in
1. Systems modelling (using the ORATOR model developed at UA);
2. Geographical information systems;
3. Statistical analysis in R;
4. High level use of Excel;
5. Programming in Fortran;
6. Qualitative socio-economic data collection and analysis; and
7. Policy analysis.