Month: August 2021

Water management is crucial in the sustainable development of the food systems agenda. In Sub-Saharan Africa, evidence points to a future with decreasing precipitation (IPCC, 2019). Therefore, detailed characterization and understanding of the hydrological components of the water systems are of paramount importance to planning, designing, implementing, and fostering the adoption of water-conserving practices. As part of my thesis, I focused on conducting a regional assessment of crop water requirement and availability of effective precipitation (PrpE) between 2020-2035. The analysis showed about a 30% projected reduction in the availability of PrpE which means increased drought stress for Maize, cassava, soybeans, and groundnut production. The results revealed that crops are likely to suffer from water stress conditions during the mid-growth stages which can negatively affect yields. However, water-conserving farming practices such as mulching and cover cropping can help in alleviating the adverse impacts of water stress in smallholder farmer communities. Conclusively, a food systems approach that integrates water use efficiency in crop production is key in the sustainable development program.

Source: Irmak (2008)

Figure 1: Schematic representation of Maize Crop Water Requirements based on growth stages

*High Kc values are indicative of higher crop water requirement

IPCC (2019) ‘Summary for Policymakers. In: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems ‘, Intergovernment Panel of Climate Change. [Editors: P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.- O. Pörtner, D. C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M. Belkacemi, J. Malley].

Irmak, S. (2008) ‘Evapotranspiration’, in Jørgensen, S.E. and Fath, B.D. (eds.) Encyclopedia of Ecology. Oxford: Academic Press, pp. 1432-1438.

I’m happy that I have finally submitted my MScCCAFS dissertation which I have been working on for the past 3 months. My work focused on investigating water availability for crop production in the Chongwe watershed of Zambia. I used the Water Evaluation and Planning system to quantify both water demand and supply delivered. Furthermore, I calculated the crop water requirements of Maize, Cassava, soybeans, and groundnuts in the study region. The trend clearly points to a future with limited water availability for crop production, especially for maize and cassava. Although the projections point towards the unsuitability of the study region for maize and cassava production, climate adaptation strategies such as breeding for drought/heat stress tolerance and water use efficiency can be beneficial. Furthermore, water-conserving farming practices such as mulching and cover cropping can help in alleviating the adverse impacts of water stress on smallholder farmer communities.