Water footprint analysis of teff production in Ethiopia

Teff is the most important crops of Ethiopia, contributing significantly to agricultural income and food security. Water footprint (WF) is one of the indicators used to show the pressure on water resources. It provides a useful perspective on how and where freshwater is used in the supply chain, which facilitates decision-making processes. In agricultural production, the part of water requirement of the crop that is met from the effective precipitation (Peff) is called green water footprint and irrigation water requirement that is met from ground or surface water is called blue water footprint. The goal of this study is to determine the water footprint (WF) of teff production in the four largest teff-producing Ethiopian regions for the 2019–2020 production period. The study also aims to calculate the economic water productivity of the teff crop in the specified year. The water footprint of teff production was computed using the CROPWAT 8.0 and CLIMWAT 2.0 models. The average effective rainfall (Peff) was 330 mm, while the average teff crop water requirement was 309 mm per growing season. Teff's average water footprint was 3089 m3 /ha. The overall water footprint of the teff crop across the country in 2019/2020 was 9 billion m3. The green water footprint component accounts for 78% of the overall annual WF. The remaining 22% represents the blue water footprint. The total water footprint of teff per ton was 1777 m3. Teff's economic water productivity in the 2019/2020 production period was 0.68 USD/m3.