Assessing the impact of climate variability on maize yields in the different regions of Ghana—A machine learning perspective

(Upper West region, Upper East region, and Northern region) and the Rain Forest zone (Ashanti region, Eastern region), but has a strong impact on maize yield in the transitional zone, as evidenced by the prominent position of the feature in the Brong Ahafo region. Addi- tionally, the Brong Ahafo and western areas’ temperatures are more significant compared with those in the rest of the nation. The upward trend in maize yield can also be attributed to the advancements in agricultural technology and practices. Farmers have gained access to better-quality seeds, improved irriga- tion systems, and modern farming machinery, all of which have contributed to higher maize yields. Additionally, the government’s focus on agricultural development and support pro- grams has had a positive impact. Through initiatives such as subsidized fertilizer distribution, extension services, and training programs, farmers have been empowered with knowledge and resources to enhance their farming techniques, leading to increased yields. However, the maize yield in the northern region of Ghana (Fig 2h) has been experiencing a downward trend since 2016, therefore, future research should look at the cause of the declining maize yield in the region. The rise in maize yield across all regions in Ghana is not only significant from an agricultural standpoint but also holds economic and food security implications. Higher yields contribute to increased food production, reducing dependency on imports, and ensuring food self-sufficiency. Moreover, surplus maize production can be sold in markets, generating

income for farmers, and stimulating economic growth at both local and national levels. Discussion Summary of Key findings The agricultural sector of Ghana is heavily dependent on maize production, which also has a significant impact on both economic growth and food security. However, variabilities in maize output across the nation’s regions can pose complications for farmers and decision-makers. We go over the main findings and implications of our assessments on maize yield, climate var- iables, and their importance in Ghana. The Greater Accra region shows a high degree of fluctuation in maize production when assessed, which suggests a lack of consistency over time. The Western region, on the other hand, has the lowest coefficient of variation, indicating maize output that is more dependable and predictable. Notably, the Greater Accra region also has a lower average yield in compari- son to other regions, suggesting possible factors affecting maize farming there. Further investi- gation is required to determine and address the variables affecting maize production in the Greater Accra region considering this study. Even though there are variabilities in maize yield in all regions, all of Ghana’s regions have seen a substantial increase in maize output, according to our data. The development of agricultural technology, better farming methods, and govern- ment support programs are all responsible for this growing tendency. Productivity has signifi- cantly increased because of improved irrigation systems [28], access of high-quality seeds, and

sophisticated equipment. Furthermore, measures like subsidized fertilizer delivery, extension services, and training courses have helped farmers become more independent and improved their farming practices [39]. The increase in maize output has implications for the economy and food security, lowering reliance on imports and promoting regional and national eco- nomic growth. Among the climate variables, precipitation patterns, and temperature have significant impact on the productivity of maize. The higher average temperatures are brought on by the Guinea Savannah Zone’s connection to the Upper West, Upper East, and Northern areas. The average temperature in these regions was higher than the average for the rest of the regions, revealing its position as the warmest zone in the nation with less precipitation. The variability PLOS ONE Impact of climate variability on maize yields in Ghana PLOS ONE | https://doi.org/10.1371/journal.pone.0305762 June 25, 2024 19 / 24