Impact of rainfall variability on maize yield in the KwaZulu-Natal, North-West and Free State provinces of South Africa (1987–2017)

Abstract

Climate change has increased temperature, caused drought in places like North West Province, and reduced crop yield. This study investigated the climate change impact (rainfall) on maize yield (1987 -2017). The objectives were to determine the climate change impact on maize yield for Kwazulu-Natal, North West, and Free State Provinces of South Africa, assess the difference in climate change impact on maize yield between the three provinces. Rainfall and maize data were collected from WeatherSA and DAFF, respectively. A Pearson Correlation Analysis revealed a weak negative correlation between rainfall and maize for KwaZulu-Natal and Free State Provinces. However, for North West Province there was a weak positive correlation between maize yield and rainfall. Rainfall determines yield, if excessive, it becomes detrimental to crop yield. Climate change affected negatively on maize yield, rainfall above maize requirement was not beneficial to crop yield and drought reduced yield too. ANOVA results revealed that the group mean yield between the Provinces was different, with KwaZulu-Natal having the highest mean yield. The climate change impact on maize varied between provinces, KwaZulu-Natal Province was least affected, however, North West Province was the most negatively impacted with drought events leading to reduced maize yield.