Effect of rainfall and temperature variability on maize yield in the Asante Akim North District, Ghana

Abstract

One of the largest consumed and grown cereals in Ghana is maize. However, there is a dearth of research on the response of maize yield to rainfall and temperature variability in Ghana. Precisely, prior studies conducted in Ghana have employed only quantitative approaches to explore the effect of climate variability on the yield of food crops including maize. However, this study combined both quantitative and qualitative approaches to investigate the effect of rainfall and temperature variability on maize yield in the Asante Akim North District of the Ashanti Region, Ghana. Since research will help the decision-making process of the policymakers at several cadres of managerial leadership of the United Nations Sustainable Development Goals (SDGs) all around the world where the goals are intended, this study will have significant implications on the attainment of the SDGs particularly Goals 1 (no poverty), 2 (zero hunger), and 13 (climate action). Pragmatic research philosophy was utilized with the aid of questionnaire surveys involving 150 maize farmers and three focus group discussions in three purposively chosen communities (Ananekrom, Juansa, and Agogo). The Mann-Kendall trend test was used to evaluate the trends of rainfall, temperature, and maize yield data for the period 2012 to 2021 in the study district. Multiple regression was used to assess the effect of rainfall and temperature variability on maize yield. Results showed that the surveyed maize farmers perceived rising temperatures and erratic rainfall patterns. Similarly, the Mann-Kendall trend test results revealed a significant temperature rise (p < 0.05) and an increasing rainfall pattern (p > 0.05). The increasing annual rainfall and rising temperature trends increased maize yield significantly (p < 0.05) in the district from 2012 to 2021 contributing about 70% of the yield variation. The surveyed maize farmers implemented key on-farm and off-farm practices including planting drought-resistant maize varieties, crop rotation, changing diets, and selling assets to adapt to the rainfall and temperature variability. The increasing annual rainfall and temperature patterns significantly affect maize yield positively in the Asante Akim North district stressing the need for continued implementation of adaptation practices such as planting high-yielding and drought-resistant maize varieties to enhance household food security. Furthermore, the results demonstrate the urgent need for policy formulation by policymakers to make maize production resilient to the adverse impacts of the changing rainfall and rising temperature trends in Ghana.