Model prediction of maize yield responses to climate change in north-eastern Zimbabwe

Abstract

The increasing frequency and severity of droughts and floods, the shift in onset of the rains, increasing intensity of mid-season wet and dry spells and variations in the cessation of the rains in the last 50 years have been
identified in the Intergovernmental Panel on Climate Change Third  Assessment Report (IPCC-TAR) as a major consequence of climate change. This paper presents a study that was conducted to project climatic trends in Zimbabwe by the end of the 21st Century. Observed data of the last three decades (1971 to 2000) from several climatological stations in north-eastern Zimbabwe and outputs from several global climate models were used. The downscaled model simulations consistently predicted a warming of between 1 and 2 ºC above the baseline period (1971-2000) at most of the stations in the period 2046-2065. Most of the models predicted that for the same period, rainfall will decrease by an average of 10 mm for each month for October to December; while there will be
an average increase of 10 mm for the months of January to April. The AquaCrop crop production model simulations predicted that climate change will shift planting dates towards delayed planting in the period 2046-
2065. The results further showed that using traditional static sowing practices in the period 2046-2065 will result in maize (Zea mays L.) yield reductions, while adopting dynamic planting strategies will result in highest maize yields for short season cultivars.