Review: Climate change and the water footprint of wheat production in Zimbabwe

Simbarashe Govere,Emerson Z Nyakatawa,Justice Nyamangara

doi:10.17159/wsa/2019.v45.i3.6748

Simbarashe Govere, Emerson Z Nyakatawa + Show 1 more

Open Access

https://doi.org/10.17159/wsa/2019.v45.i3.6748

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Journal: Water SA	Publication Date: Jul 31, 2019
Citations: 4	License type: cc-by

Affiliation: Chinhoyi University of Technology

Abstract

Reductions in the water footprint (WF) of crop production, that is, increasing crop water productivity (CWP), is touted as a universal panacea to meet future food demands in the context of global water scarcity. However, efforts to reduce the WF of crop production may be curtailed by the effects of climate change. This study reviewed the impacts of climate change on the WF of wheat production in Zimbabwe with the aim of identifying research gaps. Results of the review revealed limited local studies on the impacts of climate change on the WF of wheat production within Zimbabwe. Despite this, relevant global and regional studies suggest that climate change will likely result in a higher WF in Zimbabwe as well as at the global and regional level. These impacts will be due to reductions in wheat yields and increases in crop water requirements due to high temperatures, despite the CO2 fertilization effect. The implications of a higher WF of wheat production under future climate change scenarios in Zimbabwe may not be sustainable given the semi-arid status of the country. The study reviewed crop-level climate change adaptation strategies that might be implemented to lower the WF of wheat production in Zimbabwe.

Highlights

Agro-ecosystems are the largest users of water accounting for 70% of global withdrawals and 90% of the global water consumption (Shiklomanov and Rodda, 2003; Haddeland et al, 2011)
Rekacewicz (2005) concluded that the mean annual rainfall received during a rainy season has decreased by about 5% since 1900 and rainfall patterns have shifted; more rainfall is occurring at the beginning of the season, in October, and less rain is being received between January and March
This paper fills an important gap in climate impact studies by providing a review of the anticipated climate change impacts

Summary

Introduction

Agro-ecosystems are the largest users of water accounting for 70% of global withdrawals and 90% of the global water consumption (Shiklomanov and Rodda, 2003; Haddeland et al, 2011). Accelerated population growth, change in diets and demand for green fuels means that global freshwater demand in agro-systems will increase to cater for the rising need for food, fibre and biofuels (Falkenmark et al, 2008; Gleick, 2003). A possible solution to close the gap between agricultural water demand and availability might be to increase the crop water productivity (CWP), that is reduce the water footprint (WF) of crop production in agro-ecosystems (Hoestra and Mekonnen, 2012). The various nonlinear ways in which climatic factors can affect crop production via geographic and crop-specific factors mean that the precise impact of climate change on the WF of crop production for many countries is not known. There is a need for the assessment of the impacts of climate change on crop production WF at the national level (Sun et al, 2012)

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