Simulating the impact of climate change on maize production in Ethiopia, East Africa

Abstract

Background: Climate change is expected to significantly impact agricultural production across Africa. While a number of studies assessed this impact in semi-arid southern Africa, or tropical West Africa, only a limited number took interest in the mountainous and climatically varying Ethiopia of eastern Africa. This study assesses the impact of climate change on maize production in three representative sites of maize growing areas in Ethiopia. The assessment relies on the DSSAT crop model simulation of maize under current climate and future projections (19 Global Climate Models and 2 Representative Concentration Pathways). The period 1980-2010 was used to represent the baseline climate, while future climate projections cover three periods; near term (2010-2039), mid-century (2040-2069) and end-of-century (2070-2099). Climate, soil and crop management data were collected for the study sites representing the maize growing areas in the country. Results:Results show that maize yields will decrease by up to 43 and 24% by the end of the century at Bako and Melkassa stations, respectively, while simulated maize yield in Hawassa show an increase of 51%. On the one hand, rainfall variability and rising temperatures are determining factors explaining yield decrease in Bako and Melkassa, while projected rainfall increase in Hawassa explain simulated yield increases. Conclusion:The terrain and climate high variability of Ethiopia is emphasizing the extremely different responses of current agricultural systems to climate change. Though adaptation approached can address some negative impacts, and in some case can take advantage of changes, this study reveals that dedicated local knowledge is necessary for national and regional decision makers to respond with local relevance to a global exposure, in order to face food security challenges.

Warming and Dimming: Interactive Impacts on Potential Summer Maize Yield in North China Plain

“…It should be noted that this conclusion is based on the assumption of an invariant maize growing season. However, rising temperatures are expected to accelerate crop growth [53] and shorten the length of reproductive growth stage [54], and thus reduce the total dry biomass; similar results are also reported in the future climate projections [55][56][57][58]. Therefore, some effective management options, as well as shifting cultivars in longer growing season, must be used to offset the negative impact caused by climate warming.…”

Quantifying Agroforestry Yield Buffering Potential Under Climate Change in the Smallholder Maize Farming Systems of Ethiopia

“…We showed these positive climate change effects on maize yields are explained by strong increases in rainfall in parts of the country, which will increase the agronomic conditions for maize cultivation compared to current levels, especially in the highlands. In contrast, some area specific case studies in the country have projected decreases in maize yield of Ethiopia such as in Bako (Mamo et al, 2011), Melkassa (Abera et al, 2018) and the Central Rift Valley (Kassie et al, 2015). The previous studies are all indicative of the impacts of climate change on maize in yields in Ethiopia driven especially by limited water for the crops from higher evaporative demand with climate change (Kassie et al, 2015) and also increased rainfall variability for some areas particularly in the mehr season (Brown et al, 2017).…”

Projecting maize yield under local‐scale climate change scenarios using crop models: Sensitivity to sowing dates, cultivar, and nitrogen fertilizer rates

“…Changes in temperature and rainfall in 2040–2069 relative to the baseline were estimated based on GCM outputs. The adjusted formula for modified daily precipitation is expressed in Equation 1, while modified daily temperature was computed using in Equation 2 (Abera, Crespo, Seid, & Mequanent, 2018). where is the adjusted daily rainfall for the future years, is the observed daily rainfall for the base years, is the monthly mean rainfall of the GCM outputs for the future years, is the monthly mean rainfall of the GCM outputs for the base years, P i is the weight of each grid cell, and k is the number of the grid cells.…”

“…Changes in temperature and rainfall in 2040-2069 relative to the baseline were estimated based on GCM outputs. The adjusted formula for modified daily precipitation is expressed in Equation 1, while modified daily temperature was computed using in Equation 2 (Abera, Crespo, Seid, & Mequanent, 2018).…”