Climate Change Effect on Land Use, Cassava Production and Yield in Nigeria

Abstract

Climate change is a global challenge affecting human beings, their socioeconomic activities, health, livelihood, and food security. Cassava is Africa‘s most important staple food after maize, in terms of calories consumed and also a major source of calories for roughly two out of every five Africans. Despite being the highest producer of cassava globally with over 9 million ha devoted to cassava production annually, Nigeria‘s yield (tonnes/ha) has progressively declined. There is a need for an investigation of the effects of climate change on the declining yield status of Nigeria. The objectives of this study were to determine the effects of temperature and rainfall variability on cassava land use, production and yield between 1980 and 2021. The study employed the mixed-method (quantitative and qualitative) to analyze the impacts of climate change on land use, cassava production and yield in Nigeria. Data collection for quantitative method utilized time series data covering the period from 1980 to 2021, encompassing two climatic variables, temperature and precipitation. These yearly national climatic data were sourced from the Nigerian Metrological Institute (NIMET). The dataset ranged from 1980 to 2021 for all the stations. The historical datasets on land use, cassava yield and production was sourced from the Food and Agricultural Organization of the United Nations (FAOSTAT). Multiple linear regression was used to model relationships and project future climate impacts. Surveys (n=400 farmers) provided quantitative yield and production data and qualitative perceptions of impacts. Focus groups (n=20) generated qualitative data on adaptation strategies. Results showed increasing temperatures and slightly higher rainfall overall. Quantitative analysis of meteorological data (1980-2021) showed rising temperatures and rainfall trends. Multiple regression modeled relationships between climate variables and yield quantitatively. Results showed that cassava yield increased slowly pre-2000 (9.58 – 9.70 t/ha), increased steeply from 2001 to 2010 (9.60 – 12.22 t/ha), and fell drastically post-2010 (12.22 – 5.84 t/ha). The decline in cassava yield post-2010 was associated with soil degradation, poor access to improved farming materials, pest and diseases, poor management, quality of rainfall rather than amount (regularity and duration) and increase in temperature. Farmers reported delayed rains, excess rain, higher temperatures and longer sun hours as factors that negatively impacted yield. In conclusion, continued adaptation is needed based on quantitative trends and farmers' qualitative experiences in coping with climate risks.