Centre PhD thesis explores small-scale water systems in sub-Saharan Africa
This is one of the key conclusions in a doctoral dissertation by centre researcher Elin Enfors. The dissertation will be defended at Stockholm University, 15 May at 13.00.
In semi-arid and dry sub-humid sub-Saharan Africa (SSA), high poverty levels in combination with a heavy reliance on small-scale rainfed agriculture make rural livelihoods difficult. Upgrading current farming systems, in a way that safeguards productivity beyond field-scale, is urgent for local communities.
Focus on alternative development trajectories
The thesis builds on an in-depth case study of the Makanya catchment in Tanzania. It consists of five papers that approach questions of alternative development trajectories for smallholder agro-ecosystems, and effects of SWSIs on key variables in the system, from varying perspectives:
- Paper I presents a conceptual model for interpreting multi-equilibrium dynamics in dryland agro-ecosystems, and analyzes Makanya´s development over the past 50 years.
- Paper II investigates farmers´ strategies to deal with drought and the impact of the local Ndiva supplemental irrigation system on coping capacity.
- Paper III studies the effects of conservation tillage on yields and controlling soil variables.
- Paper IV explores four future scenarios for the catchment, and discusses the potential role of SWSIs across them.
- Paper V moves beyond the local scale, and maps dryspell frequency and trends over time in a drylands—in-SSA perspective.
Dry spells maintains poverty traps
The results of the research show that smallholder farmers in agro-ecosystems such as Makanya depend on a wide array of on- and off-farm ecosystem services for their sustenance. The productivity of the surrounding landscape is especially important when crops fail. Furthermore, long dryspells constitute a major constraint in these agro-ecosystems.
- In Makanya long dry-spells have become twice as common over the past 50 years, and frequently cause crop failures. This is a driver for land degradation, and it seems to maintain a climate—related poverty trap, Elin Enfors says.
SWSIs provide opportunities for dryland farmers to shift their agro-ecosystems towards more productive trajectories through a number of mechanisms, including lowered crop failure frequency, altered on-farm water balances, and improved soil quality.
Scenario planning can support investment strategies
Although this is promising, the task of transforming these systems is tremendously complex. For SWSIs to be effective, prerequisites are farming system solutions that integrate improved water- and nutrient management, and broad-based investments that focus on a much wider range of issues than the water management technology in itself.
Moreover, given the large uncertainty about the future in these regions, investments in small-scale farming should be designed so that they benefit local communities across a range of potential futures.
Participatory scenario planning can both help agricultural intervention programs to identify robust investment strategies and help rural communities such as that in Makanya to navigate towards desirable development trajectories.